Topic: Hacking a BFL Single/25 to 48gh and beyond..... (Read 8431 times)

So anyway a quick update: I installed 7 more chips on my other single/30 a few weeks ago, ran well at 56gh overall. However last weekend I powered it down and it came up with only one side.

Turns out the 1850 chip wasn't working right, so I pulled it and replaced it. Now one set of FETs is working, but the other is not. Enough to keep the board hashing with a fan pointed at the running FETs but still kind of odd.

And I have another single board that has one side down. At first I thought the problem was the 1850 and swapped it, but sure enough 0 volts. Then I found the FETs were shorted and replaced half of them. Then I checked the caps and found one of them (the one between vcc and ground) was shorted, which was shutting down the chip. Pulled the cap and the board is coming up but only at .6 volts, which is kind of odd.

Just got a new set of FETs in, will replace this weekend and see what happens. It would be nice to get the other 30gh running on this board.

Never dull, always fun.

thank you I ordered 10 for 16 usd including fedex shipping

What country are you in?  Have you tried Mouser?

http://www.mouser.com/ProductDetail/Texas-Instruments/CSD16404Q5A/?qs=%2fha2pyFadugSnQ10j0BuekvPf4xb1xPwdHGhkVkF47c%3d

My unit has IOR mosfets on it instead of the 010NE2LI ones, unfortunately I am out of town for the weekend, so cannot get you the info on them at the moment.

Yes Q3 is damaged and need replacement any idea where i can buy this FET?

CSD16404 = 7030L

Q3 in that center photo looks a bit cooked.  Hope the board/pad under it is not damaged!

Thanks for the datasheet links.

here closeups of the FET which can blow so easy:







now I have to source them, bfl wants the whole box sent to them, not just the board, what a waste of energy.
I see 2 typ of FET :
CSD16404 TI 38E MF3X 3E http://www.rom.by/files/CSD16404.pdf
and
010NE2LI HSA335 http://www.infineon.com/dgdl/BSC010NE2LSI_rev2.2.pdf?folderId=db3a304313b8b5a60113cee8763b02d7&fileId=db3a30433072cd8f01308d8d1cdf33de

and here is FET of 5gh single bfl: left side is 7030L FET maybe same as CSD16404

Not sure I understand what you're asking? When you factor in shipping and such though it might be cheaper to do it locally.

C

how much for you to supply everything and send to UK a 48gh rig?

cheers

zCz

First, I would read the numbers off all six, post them, then remove them. They sometimes used different parts.

Then I would try powering it up *BUT NOT MINING ANYTHING*. The other three FETs shuould be enough to power up the chips (note they will fail on mining) but what you need to see is if there is 1 volt between that pad over on the right and ground.

If not, the driver chip is also blown and this becomes harder. If it does show 1 volt shut down immediately and order the FETs. Remember, they have solder on their backs that attach to the board so you have to heat the whole chip not just the um. pins on the ends.

C

I have shorted power rail and soon with help of this will get my bfl50 working again

here is picture of shorted FET bfl single 50 , see the burnt brown thing, luckily I did not try other psu like so many others causing more damage.



who sells those FET and what type are they , name? tnx

Interesting: I don't like the Corsair 750m as much as the 500. Although it does have more power without a doubt, the ribbon cables it uses are really kind of undersized in terms of wire gauge. There are "four" PCIe plugs, but two of them are on the end of each ribbon cable, and the gauge of the wire going to them both is a bit smaller than the gauge of the 500's single plug. Result is what's the frigging point?

Right now I have a 48gh single running on one side, and a 32gh single+35gh chili running on the other. The second wire is getting a bit warm going back to the power supply, which of course means overload and *inefficiency*. And although I can run one 24gh overclocked jally on a 12 volt line, I can't run the 20gh jally on the same line, different plug because *it* gets a bit warm.

Drat. So if you're looking for power supplies, 2 500 watt units are going to be better than a 750 in more ways than one.

C

Just got the 750. The 500 was not happy; things are much more merry on a 750 watt unit. And I now have more room for some more singles.

Other than that everything is working fine. Still a solid 48gh, that one I fixed is at a solid 31, just keeping an eye out for some chips to boost it to 60.

12v x 38a = 456w

Single Rail but only push to 30a to keep it safe.

not rated for 24/7 full load, the rail amps available are "Surge" specs.

38a surge 30a 24/7

If you want bulletproof PS then follow this thread, cheap too. pennies on the dollar for old server P/S.

https://bitcointalksearch.org/topic/server-power-supply-interface-board-for-standalone-miners-and-gpu-rigs-379677

No more soldering for the tool less, put the toy PSs back into the game boxes.

here are some examples, 12v 60a 90+ efficient:
https://www.google.com/#q=Z750P-00

Funny that you are writing about using a CX500; I was just commenting on a post about the 12v available amps and this happened to be the second post I ran across! Out of curiosity what A does your CX500 say for your 12v line?

Interesting thing to note: Last night my 32gh Jalapeno blew up it's power supply (a crummy 300 watt ATX one from Ebay, $20) so I put it on my CX500 along with a high power burning Chili and the 48gh single. The single dropped off line this afternoon and went to zero gh hash rate, which was very odd. So I moved the 20gh unit onto the the CX500, moved the Jally to the other CX500 and now everything is stable.

So it does appear that power supply issues (yes, the 500 watt Corsair was overloaded) can cause oddball issues. I just ordered a 750 watt Corsair to come by Friday, that will fix the problem long term:

Also note that crappy power supplies are not worth it for miners.

C

Sell them to me.  I might donate one for lightfoot to tear apart.

This single is really interesting. It's an early October model, hashes at a solid 32gh which means it is hitting the 30gh limiter in the software which means A grade chips. The heat sink is the good copper type and is secured to the chips with a glue so strong I am not trying to remove it. It's super stuck on there, so I'm leaving that alone forever.

The odd thing is it has only one fan connector, no sinks on the bottom other than the bottom heat sink, and only one fan that the DPO replaced with a "quiet fan" that doesn't move air for crap. Temps were at 80c, which was hot.

So.... I got a fan with two broken blades from my box of crap, put it on the unit with standoffs from all my now parted jallies, and put a 40 ohm resistor in series with the inside fan so the darn thing wouldn't vibrate too much. Best I can do. Seems to be in the 60's now, will let it hash for awhile.

However it really needs two fan ports. Well, four. And a second fan, and 6 more power control chips, and a power chip, and parts from my other non-working jally, and six more chips....... :-)

I'll work on that. Soon.

C

Well, got the chipmunk single today, interesting little thing. It seems to be an October generation single/30, has the really good heat sink, and no fan on it. Just one fan on the end that the guy replaced with some "quiet" fan which means less cooling.

Anyway yes, it does have a hole in the side, looks like an iceberg. And yes, it would not work when plugged into a computer, no recognition, no FT_PROG access, zilch. Dead chip, right?

Wrong.

If there's one thing I learned from Atlas Shrugged, aside from the fact that sex can be boring, icky and kind of rape-creepy it's the words of Atkison, who said "Check your premises". So I looked at the cable (mine, fine), then looked at the USB port. And found that the USB port was a tangle of wires inside, looks like it somehow ripped itself apart.

That would do it.

So I went to my junker jalapeno board, heated it up on the preheater, 375F for 5 mins, then 400c for 30 seconds to float off it's USB port. Did the same on the bad board, put the replacement port on, 45 seconds of heat at 400 after preheat and gentle pressure on the back, and....

Up it came. Hashed at 32gh at 75C which is kinda hot for a single. I'll find an old fan and put one on for the moment while I figure something else out.

I really think though that I could fix a rainy day... It's never dull. But now I have space for 8 more chips. Well, 6 more. But getting there....

C

What kind of cooling are you doing on it? And whats the max you have hit so far? I am really interested in this overclock because i think its worthless to power up my Single 

they are making pretty exact 60 GH each.
not more and not less.

i was already hoping that it´s possible to make those "aircraft turbines" little more effective so that they make enough hashpower equal to noise what they are making... 

thanks for your informations!

Once again, if they're running at 60 then there's not too much further they can go. We could try swapping out the resistors and flashing the firmware, but unless they are seriously underperforming it would only be a few gh of extra speed.

The systems with opportunity seem to be the 25's, 50's, and jalapenos.

C

i have some 60GH/s singles here. if you would have interest to "push" them up, i would not have anything against.  . no risk no fun!

would you have interest to try?

Where you come from?

if you have interest, answer here or just PM me.

Honest answer, not sure never seen one. However although the little single (aka jally) boards were specified for the mini-rig, I think they went with the new style single boards running flat-out at 60gh each (8 boards).

From what I have heard, they used the best of the best chips in those, so all chips are probably hashing at full rate. Therefore, not a whole lot to do other than enjoy the thing.

C

Yes you and few others could take any advantage of it, if the miner is fried.
Will definitely be sending you work, as either advice on where to go, or my own for rechipping if I get a suitable miner somewhere.
Keep waiting for the market to get flooded with em as the bigtimers find time to sell em off or something
cheap, like the old server powersupplys  pennies on the dollar.

Hey Lightfoot,

What do you think you could do to a BFL mini-rig?

I think it's 16 little singles?  480Ghash.

Got the wrong size ones, next time I'll use my watchmaker's calipers to get the sizes right.

As for the price, it's ebay so it goes what it goes for. Actually $200 is a good price if it works, and if not $25 a chip plus reballing could be worse. I should have it Tuesday, we'll see what happened to it pretty quickly.

C

Ok, I see R36,R11 in the photos above one for each side. Not really into SMT but think I can do this. Are these a 0402 package ?

Thanx

Sounds fun did you ever get the rest of the caps from mouser or want to see if it makes any difference on your 1v supply issue.

edit: saw the chewed on one, thought he wanted to much as it looked like he arced the power input area pretty bad.

Update: Today I took apart one of the single/30 power supplies because although it seemed to provide power it did not light the LED. Fan would run. Found that although the power supply is a pretty solid design (and the neutral goes to GROUND as it should) I did figure out why the LED wasn't working; cold solder joints. Looked soldered, but wiggling the LED would cause it to light.

Used soldering iron to reflow solder, now works fine. Also touched up the power cable lines as well, I wonder if that is the problem with some of these supplies; the wires run in parallel, but if one of them was badly soldered by the power supply company then it would go high which would result in a lot more resistance on the remaining wires, and lower power going to the single. Which would either shut down chips or keep them from coming live on startup.

Interesting.

Update: I did switch the heat sinks so that the best one (the old style BFL with the heat pipes) is on the 8 chips at the exhaust end of the unit and the newer one (black, fins facing properly) is on the intake side. Also put heat sinks under the board on the center FETs (6 chips starts the warming trend) and it's hashing 49gh at 72c. Very good, stable.

I also put another capacitor on the board's 1 volt supply, that was hard as those open capacitor pads are near the last chip which is on there with normal lead solder (which has a significantly lower melting point than ROHS stuff) which made adding the component dicey. 425c for 40 seconds, air angled as much as possible away from the chip. Hashing errors are down from 2.2 to 1.8, most all the errors seem to be on the last chip added, so it might be a bit of a clunk (or took a bit of damage from the reballing)

Overall things are working well otherwise, I'm going to wait for the chipmunk-chewed single to come in and continue research on that.

C

Very interesting thing here:

Last night I added another chip to this single: It now has six chips on the right, 8 on the left. I fiddled with the fans a bit, then put everything back to stock condition (both inside ones pointing up, etc) and it hashes at 48-49gh constant with a 76-77c temp (as opposed to 75 before)

However it's now running with 2% errors instead of <1%. And in looking at the stats the errors are coming from the right side, but from all sorts of chips and *not* simply the one that I put in.

Now, my 1 volt supply is missing about 4 of the filtering capacitors because I stole them from a jalapeno, but I'm wondering if this is a filtering issue on the 1 volt line. A bit more noise coming into the chips causing increased random errors (my code shuts down bad cores to save on heat, so what remains are truly random errors). It's running fine and the overall effect on hashing is minimal (<1gh) but still something odd to note.

I'll see about ordering some more capacitors and putting them on the next time I get some chips to try out 7 chips on the unit.

C

R36 and R11 I think.  Will be between two of the ASICs. Should have 828 on the top.  It will be a 7K resistor.

This sounds g8, any chance of a pic identifying that resistor.

I'll post pictures and funny commentary, don't worry. Maybe it was shards of metal or something. But to be honest the problem was probably that he didn't have the bottom plate in the little slots in the ends. It's um.... made that way.

C

"The one that looks like a metallic woodchuck was chewing on the side?"

YES! Had he never heard of a multimaster?
It's best in your hands than mine.

The one that looks like a metallic woodchuck was chewing on the side? Yeah, I picked that one up to check out. I'm wondering if the guy fried the FTDI chip, when the USB system won't talk that is usually it. Fortunately I have a spare chip here, so I could get it working again if that's it. Otherwise I'll have a ton of chips to re-ball.

In the meantime I put a reballed chip on my unit here. The concept of using resistance was useless, as the resistance between +1 and ground is basically 0 ohms. Which makes sense if you think that 8 chips can pull over 120 amps thus R=e/i or 1/120=.0083 ohms.

However it's working, and with 14 chips populated I'm cruising at 49gh and 76c. I did try running one fan pointing up and the other down, but I could hear one of the fans "singing" inside which means it was stalling, and temps went over 81c even with the output fan running at full speed. With both fans pointing up, the temps are 76, no stall, even with the resistor in series with the output fan to quiet it down.

On to the next thing. I'll check out this oddball single and see if it can be hacked too. Never a dull moment....

C

I've had much restraint in not cracking my case open. It's a 50 hashing closer to 48. There was a fried one on ebay that looked interesting to tinker with.
I'll just watch you and learn for awhile.

Doesn't the ATMEL chip need 3.3V?  I seem to remember seeing something when I flashed my friends LS about 3.3V on the program... Also, looking at my little, isn't that gold rectangle a 1.0V test point?

Each side of one of my singles the 1V line measures 14 ohms to ground.  This one has the revision B chips.  Maybe the revision A chips are lower?  I always check the

1V line after the resistor mod to make sure I did not bridge it to ground.

Also, installing a 7.5K resistor was very successful.  Gained 3Ghs (57-60) and error rate went down to around .34% (was 1.9% at 57Ghs).  Temps went up 4 Degrees

though.   Still this mod seems to be a very easy way to push an underperforming single/jala up to speed.

And in the meantime, it looks like I just bought a 100% BROKEN single. So now I'll have another thing to figure out and keep me busy...

C

You know, I didn't think about that. If I could find the 3.3 volt test point I could also find that as well (3.3 is shared between sides). But I seem to recall a loaded jally has a very low resistance to ground. What would it be, probably under 1 ohm.

I'll do that.

To check the 1 volt, can't you check the resistance to ground of the 1 volt supply like you could on a Jally???

Look for a 7K resistor between two ASICs.  On the jalapeno it is R11. Not completely sure on the resistor with singles but the ASIC layout looks the same as a Jala.

I am going to mod one of my singles this week with a 7.5K resistor.  The one I am changing the resistor in only does about 57Ghs with stock firmware.  Hope this

puts it over 62Ghs.  Will post results.

Ok, I'm ordering the resistors. 0603 size, 8.2k. Question: Do you know which resistors to do on the single board? I'm sure there is one per side, haven't tried tracing them out yet. The MOSFets on the Singles are more durable; they should handle it.

C

"This is a stock BFL supply current limited"

Limited to how many amps ? use automotive fuses 5 7 10 15 20 25, they are cheap start low on the feed lines. (newer plastic style with legs).
electronic fuses are available in fast blow, but harder to get.

Not sure how BFL does it, prolly a very fast sense digital circuit in the supply somewhere.

EDIT: Just thought about all the horror storys of the older BFL jally supplys so all bets are off on this one ....

Ok, here is an interesting question/problem:

Normally when I add chips to a jalapeno I plug it into the "danger supply". This is a stock BFL supply current limited so that if a chip is shorted the board will come up with a "beaconing" 12 volt LED instead of blowing the 1 volt supply to hell. It's worked well (this is how I found that old style chips can short internally) but with the single, there's a problem:

I can't fire the unit up on a jalapeno supply. And even an 8 chip jally will not boot with a jally supply, you need to use a big supply. Which means if you short, you're dead.

What can I do to protect the 1 volt supply lines as I add more chips? I'm confident that I can add factory chips, but I worry a bit that a reballed chip might have a slightly out of line ball. Normally not a problem, but if it shorts the 1 volt line....

Any thoughts?

C

Ok, some pictures of this whole thing.

First, the board with 5 chips added to it, and the extra FETs and parts



Close up of the left-side FETs. Remember that the board sides are mirror images of each other.



Good shot of the board when I put on the first choke. Nice solid 1 volt.



And finally a shot of the other FETs and the driver chip during install.



Overall not bad, I'll put a sixth chip on it tomorrow or Tuesday based on how I feel.

Ok. In the meantime all together, total of 5 chips on the right side, 8 on the left, both power supplies operational.

They way to test the power supplies for shorts or screw ups is to not install the choke, and check the voltage. If it's 2 volts or so the chip is good, if it's zero or something else you have a problem.

Once I put the choke on the overall voltage on the rail was a rock-solid 1.018 volts. Not bad, not bad.

The unit is now together and hashing at 48gh at 65c. Heat sinks are installed on the center FETs only since those get the least cooling. Oddly enough the stock fan was pointing *up* so I set the second fan to point up as well. I might try reversing it later, however I think the backwash of the fans going down will disrupt the cooling air going across the heat sinks (which it does nicely since the fins are parallel to the main air flow all around)

Edit: I changed it so the first fan points down, then the second up. Reason being I want the air to come in, be forced over the first heat sink, then zip up through the second sink, then out the unit. Keep the air flow smooth as possible, otherwise it bunches and your fan blades stall. Temps are 72c now, and quiet.

I'm still only feeding it with a single molex plug, part of the reason I am not going further on chips. The other reason is I am not feeling well today, so I'm done for the moment. Will post some pics as soon as I can find a USB cable for my phone.

C

Awesome, thanks, I got an 8-pack on order now

The heat sinks are Enzotech's. Nice stuff actually, waiting for another batch to come in.

Right now working on adding chips 3 and 4 to the blind corners, will then add the FETs and go from there.

Edit: Chip 3 on and working, doing chip 4 and the six FETs. Wonder if it will read 1 volt even without choke 2 on there (ie: does the chip have a single point of reference for voltage sensing on the rail, probably)

C

bump to follow! 

Sounds like you are having fun so far, nice accomplishment!  I do want to ask though... where do you get those square heatsinks you use on the back of the board?  I've had no luck finding any in my searches.  I also noticed you only put heatsinks on 1 of the 2 sets of FETs and on the ADP.  Any reasoning on that?

Well, that was a fun job. Microsummary: Ten chips on the board total, hashing at 35+gh, not bad. I really can do anything with anything and a Mouser catalog.

Quick details:

1) I don't have my darn heat sinks in, so I had to use some old small ones. Yuck.

2) I need to make a new back plate or something for this. I have the right heat sink, but it's balance on two chips right now, not great.

3) The 1 volt supply came up rock-solid. It must do the voltage sensing after the choke coil. Ok, makes sense.

4) Running one chip I heard a buzzing on the board. Added 5 12 volt caps on the right side. Added another chip buzzing still there. Turns out it was the POS BFL power supply buzzing probably because it's overloaded with 10 chips.

5) It really is working, maybe tomorrow I'll add the other six FETs to share the load. Which means removing that BFL heat sink on the left set of chips, not sure how to do that. Heat? Chisel? Putty knife?

6) Technically I have to remember that the 1 volt supply on the right here is handling the chip load with 1/2 of the FETs. So right now it's running equal to a 4 chip jalapeno.

7) I was too lame to put a fan on the second heat sink (it's the super-good one) so I just put a 120mm fan on the end blowing in. With the case on it should keep things reasonably cool, we'll see.

So now I have this thing running along with the Chili on one 500 watt supply. The other 500 watt is running an 8 chip, 2 7 chips, a five chip, and a four chip. Hm, it may be overloaded. Great... Edit: Nope, it's pulling 470 watts from the wall which is fine. So you can run a max of 32 chips per 500 watt supply. I'll have to remember that.

Pics tomorrow, have a date tonight.

C

Updates:

1) This is not easy :-)

2) Have the chip, 6 fets on, no choke, one capacitor on the 1 volt line. Note that oddly enough the 1 volt connections between the two sets of 8 chips are *NOT* connected. Note also that if you try to power with a 1a bench supply you will think you're dead. Man up and plug it into the big BFL supply. Either it works or it blows.

3) It seems to work. I see 2.5 volts at the choke inlet, remember choke is not on yet. Shorted the choke pads quickly and saw a nice solid 1.018 at the 1 volt test pad. Other 8 chips appear to come up on the other side.

Next step: Heat board, put on 5 more 1 volt capacitors, then try it out. I should get a solid 1 volt, in which case I'll check to see if I can put a chip on the board.

C

Fan : 120x120x25 is size Delta is brand gateway servers use em.

"Few" meaning three  leads on em...12v 4000rpm 45dba 130+ CFM 3wire

AFB1212SH
http://www.ebay.com/itm/Gateway-960-8006323-Delta-AFB1212SH-Back-Case-Chassis-Fan-30-Day-Warranty-/170822936596?pt=US_Computer_Case_Fans&hash=item27c5d72814

http://www.ebay.com/itm/Gateway-Delta-AFB1212SH-Back-Case-Chassis-Fan-/281046185168?pt=US_Server_Fans_Cooling_Systems&hash=item416fa874d0

http://www.ebay.com/itm/Delta-Elec-AFB0812SH-12V-DC-Brushless-Fan-/350343725894?pt=LH_DefaultDomain_0&hash=item51921d0346

Thank you for the Molex information. I think a stock corsair power supply will be able to handle 12 chips which is what I will go for this weekend; if it works I'll order some edge connectors and start moving to 16gh or so.

Speaking of which, I need another fan. Oh great, totally forgot that....

C

Also watching

Adding info on PCIE headers plugs ect.
Before ordering make sure that the peg holes match a GPU connector. Been much confusion on that due to patent on PCIE Express by STB I believe it was. Aftermarket molex are called "something" JR.

http://www.frozencpu.com/cat/l3/g44/c155/s648/list/p1/DIYMod_Parts-Connectors_Pins-6-Pin_PCI-E_Connectors-Page1.html

https://bitcointalk.org/index.php?topic=379677.60

http://www.molex.com/molex/products/datasheet.jsp?part=active/0455590002_CRIMP_HOUSINGS.xml

finally to this:

http://www.molex.com/molex/products/datasheet.jsp?part=active/0455580003_PCB_HEADERS.xml

Can't wait to see where this goes   

I don't think increasing the voltage increases the heat.  Increasing the voltage allows the firmware to bring up more engines at faster clock speeds

and this is what increases the workload on the FETs.  My theory anyway.  Before I did this to one of my 3 chip jalas I noticed that only

about 39 of the engines where online and most of the chips ran somewhere around 275Mhz.  After I installed the 8.2K resistor, All 48 engines

where running and the average clock speed was about 285.  This jala hashes at about 13.1Ghs with a temp of around 42C.  The FETs aren't sinked

and only feel warm to touch after 24Hrs hashing.  8.2K sets the DC-DC to around 1.08-1.1V.  Varies per board, all 8 of mine are a little different.


I do wish BFL had tied the 1V to some type of control logic that the firmware could control.  Maybe automatically increase it when conditions

are ideal or when errors are high.  Maybe even make it user adjustable but stipulate this voids your warranty.  Kind of like motherboards do with

cpu voltage.  I can see how a setting like this could be a self-destruct button for an uninformed user/owner.

Hm. Does boosting the voltage boost the temps of the FETs on the jalapeno? I wonder because it's usually amps that cause the heat, and if you drive the chips at a higher voltage then the amps should go down or stay the same (maybe). I could see the chip temps going up more, but do the FETs?

I think if I tried this on my 8 chip jalapeno it would catch fire.

Gonna watch this closely.  I have a single that pulls 62Gh at about 64C.  Thinking about replacing the feedback resistor like I did in my jalas to put

about 1.1V into the ASICs.  Wondering if the mosfets can take this though. With the jalas is was a marked improvement with every one. +1Gh and

lower errors but higher temps due to higher clocks.  They only have 2/3 chips.  Do not really want to try this with the already strained DC-DC stage

in the single.

BTW, thanks Lightfoot, for all your effort and information.

And... I took apart the box again and took a look at the existing FETs. Good thing I did because this board has some differences.

First, the driver is not an 1850; it's an ADP 1877. Looks to be a higher power version, which is good since those are taxed. Likewise the FETs are IRFH 5250's and what appear to be 16404's from TI. Both heavier duty components than the little singles.

I also verified that the chokes are the gateways between the power supplies and the 1 volt main lines. So I'm going to order six of each type of FET, and a controller chip. I'll get the 4.7uf electrolytics from my dead jally, and will get the 470uf ones as well, although I think this board has plenty of them.

Then I will try adding 4 chips and see what happens. It's going to be slower going; I have to map out the chips by adding them one at a time and then testing, which requires a lot of heat sinking. Maybe I'll get myself a good temporary sink to run for a few minutes for testing each chip. Once I have 4 I can put on an AL heat sink or something like that.

TO be honest I was temped to toss a chip on there and see what happens. But at the same time I knew I couldn't sink it, so I will wait...

In the meantime, what is the part number for the PCI-e sockets and the fan sockets on this board? I'm probably going to need another fan, and more power input on the 12 volt side rather soon. :-)

Found the other one at Digikey. Not quite sure why they did two totally different models, but I'll give it a go and wait a few days for the chips. I do have the ones from this trashed jally unit here, but since the power supplied blew up I have no idea what kind of shape it is in. Then again I could test them with a 2 volt power supply and a light bulb circuit like I do with my IGBTs; hook it up with the light bulb between source and drain, (a LED would be safer actually) then touch source to gate and the light should go on. Drain to gate should keep the light off. Or maybe you don't need to do that with FETs; with IGBTs the residual charge on the gate is enough to keep it on.

C

Thoughts after looking at the Jalapeno schematics:

I'm guessing the Single schematics are quite similar to the jalapeno, at least in theory. And according to those schematics, it looks like the 1 volt power supply is screaminigly simple: You have a bank of six FETs being gated by a FET driver that picks it's feedback up from resistors and capacitors on the board. All the big caps, and other things are nothing more than filter units, to keep the ripple to a reasonable level.

Which is interesting. The two coils operate one to a set of six FETs; the big capacitors that are flat filter the 1 volt line, and the big capacitors that are round filter the 12 volt line. The chokes are the final stage of the output; I'm guessing they absorb any transients on the line as a result of the switching.

So in theory I should be able to build a quick and dirty 1 volt supply that is isolated from the board by simply putting on the FET driver chip (the 1850), two FETs (one push, one pull), and get a rather noisy 1 volt supply. I still need a filter cap, and if I put the coil on it will hook into the main 1 volt power bus but then I would not be able to measure it in isolation, so I might need to hot wire in a capacitor on the FET side of the coil. Then if I see 1 volt on that side I know the rest of the parts are there. If not, then I'm kind of boned for awhile as not all the supporting tech is in place.

I'll give it a shot. One set of FETs, and a second 1850. Question: Do the FETs have to be different types? One I was able to find at ease at Mouser, the other one was more difficult and I may have the wrong part.

C

First thoughts:

The Single I got was pretty stock. From what I have noticed, the first generation singles had a nasty habit of blowing up the FET drivers. A number of people have posted pictures of the results and they are not pretty. Which is not good. However the reason for this I think is not enough heat sinking on the chips. So when I flashed my unit to stock 1.2.9 software I made sure to include the following heat sinks on the bottom of the board:



Putting these sinks on gives some bottom cooling to the FET chips which I think will help the life.

Next up is to think about how to boost this unit. The normal way to do it is to add chips, and if your board is like this then you can do it pretty easily:



Note how this board has 8 chips to the left, and a full complement of components on the right. All you need to do (I think) is put chips on, as the 1 volt supply line is ready to go.

However if you're like me your board is more like this:



It is going to be a bit more of a problem.

Note how some components are missing. Especially the big capacitors, the smaller surface mount caps, and of course the FETs. And the FET driver. However the supporting small chips all appear to be there, so if we could mount the other stuff we would be in business. Equally important, the solder is there for the components, so it might be fairly non-impossible to add them. Some of the parts are kind of unique, but oddly enough I have a blown up jally sitting here.....

More to follow as I start working on this. You might be able to add a single chip on the right side, but that will probably stress the FETs out beyond their capacity (ie: They go boom). Edit: You can't. The 1 volt supplies on a single board are isolated from each other; the one on the right runs the right chips and so forth. Therefore there is no 1 volt power unless you were to jumper the pads which would be beyond stupid. :-)

More in a bit.

C

Reserved for thoughts and notes.

First thought: The Single board has some more beefy components than the older little_single. I wonder if early singles had the same components and they did an upgrade. I think they did; these FET drivers seem to be much more robust than the ones on the jalapenos. With two full sets of FETs it is almost overkill.

Also cooling is an interesting thing. I don't believe in running the singles open; what I have been doing is putting a speed limiting resostor on the output fan, adding a Noctua 120mm fan on the intake, and right now I'm running two fans on the heat sinks inside. One is blowing air down, the other up.

My thinking is that this take air from the outside, runs it down and to the left over the first sink and the FETs, then continues to run the air up through the second heat sink over the second set of FETs, then out of the unit. Nice wave form, which in my mind is better than sucking air down for the first one, then trying to suck what air is left again down for the second one. Reducing airflow is bad. The result is a nice 73c board temp and warm air coming out the end of it without a whole lot of noise.

I'm currently at 5 chips, might go to a max of six or seven chips because I have a pair that need reballing. 7 is about the limit anyway, going to 8 is a whole nother ballgame on the jallies, so why stress this unit for 4 more gh?

Edit: Went to six chips, 49gh speed, temps of 73c. That's about as far as I need to go; to get to 55-56gh is not really worth it since I have another single to boost, and power/cooling issues tend to snowball at 7-8 chips per side. Overall though a complete success.

C

Ok, I've pretty much taken the Jalapenos to their max limit (32gh, with 6 added chips and a lot of cooling) so now it's time to take on the singles. Much bigger board, has possibilities, but also has some interesting limitations.

My goal is to bring a 25gh single up a bit power-wise, maybe to 48-50gh or so. The unit I will be working with here is a standard single/25 which was bought by me running at 23.5gh tops. Which was a bit slow. In checking it out I found the chips ran slow, and one of the chips was missing from BFGMiner's point of view.

Update: Added two sets of FETs, driver, capacitors, and 5 chips. Hashing very nicely at 48gh and temps of 72c with a speed reducing resistor on the output fan.

If you're curious about the other things I do, check out my jalapeno thread at:

https://bitcointalk.org/index.php?topic=336782.0;topicseen

Here we go....