Topic: GridSeed 5-chip USB miner voltage mod - page 21. (Read 156991 times)

When you turn on anything electronic, there is an initial surge current (normally very small) which is higher than the operational current.  I have a hard time believing that turning on 20-30 gridseeds at once would generate a surge in current powerful enough to blow components unless those components were somehow 'weak' to begin with.

I think if you replace those beads you'll be back in business - hopefully no worse for wear.

I had a similar issue with a mosfet blowing (like a dumbass, curiosity got the best of me and I tried dual mining with a voltmod).  I replaced the mosfet but the gridseed just doesn't seem to run "like it used to", particularly chip #3.  But...thanks to Sandor I can clock chip #3 lower than the rest and still get 450Kh/s out of it.

Thanks vERY VERY much Happydaze, are they both the same? can someone please confirm this please I would like  to get these asap so I can get this pod back online... I dont really want to throw away $100 + 510KH...

Yes 49.9K was used I do not have any other to use. So lets thin about this for a second, HASHRA sells the 6-PIN > 10 barrel tips  and states no more than 250watt and only for scrypt. I did some research which saw someone find those can handle 192watt...  I now have 7 - Vmodded Seeds on each 6-PIN they are all working, I am just thinking to myself --- Is it or isnt it the cause, I DEFINITLEY know the 75w spec is ridiculous But I now made sure its under the 192watt as of what I found after some research was done... Not sure why hashra says 250w is the limit and if thats the
case I would of thought they should be fine.

And if what your saying the amps sky rocketted... WOuld that happen if only I was only short by 20-30watt? Do you think its because I plugged them in all at the same time and then flicked the powersupply on, maybe plug them in one by one?

Sounds to me that perhaps when you put the top heat sink back on and tightened it down, it shorted out on something like perhaps the fan red + lead? That will cause some fireworks/magic black smoke. Perhaps you should test the pod after you put it all back together too?
The burned out components look like Ferret beads to me. Good luck!

gtraah - could be power related.  Volt x amps = watts.  If you have a significant amount of voltage drop then the amps will go way up.  You used a 49.9k right?  Are you allowing 30 watts per pod on your power supplies?  That should provide a good safety margin.

I think the part in the photo is:
Device Type:  FERRITE BEAD_R1206_300OHM@100MH
Value:   300ohm@100MHz,3A

Someone else should confirm it for you.

Ok Guys I have modded 19 Pods and Itest each one after I have done it.. Now  got all 19 and I plugged them all in together for the first time after being successfully tested individually, anyway So I plugged them all in flicked the Powersupply switch and this is when I hear a small POP and flame like someone lit a match I INSTANTLY FREAKED OUT AND POWERED EVERYTHING OFF, OPENED THE POD in concern and this is what I see, I AM FURIOUS ANGRY as I HAVE TESTED EACH POD after I mod it and al worked perfect accepted shares NO HW and all perfect, but now that I plug the power in all of them I hear this POP and flames.

Please tell me what may have gone wrong here, Not enough power on the PSU cable? But not enuough power should NOT make this burn up and POP the moment I flicked he switch right? Anyway can someone PLEASE tell me the 2 chips I burnt I really would like to repair this pod... Its a waste, I am lost as to why this occured. I am using Acritc Mx-2 Compound- NON CONDUCtIvE so this could not have caused a short.

Please if someone can help me find these chips  will be greatly appreciated.


HERE IS THE PICTURE OF THE 2 BURNED OUT CHIPS, THEY LOOK THE SAME SHAPE AND SIZE. IT WOULD BE GOOD IF THEY WERE THE SAME CHIPS.
https://www.dropbox.com/s/qymhbmgvu5raq1t/20140428_203015.jpg

If someone can also give me an idea how this may have happened, please remember I test each POD after I mod and wait for a few shares to be accepted before I screw it all back together and this went in flames the second i turned the power on ... I was thinking maybe I tightened it to tight and the copper heat sink touched something to short out? And no I have not used any copper shims yet.

You are absolutely right! Zig's? mod (I knew something was fishy about that) SHOULDN'T cause any problems, but it DOES. Someone needs to get to the bottom of this before other pods are destroyed, accidently! That's the way electronics experimentation goes. You think one thing should happen, then something else unexpected happens. Back to the drawing board. But in this case, even the drawing board falls over! Total bummer!

I could screw up any mod   I bet.  Sorry ZiG - I'm not blaming you at all.  I did the first pod and it has run for several days.
Re: C35 - the clicking came before accidentally bridging that.  I took photos and planned to post them. It looked good from several angles.
I suspect the clicking has to do with me making a poor solder connection, maybe even up at con3.  The bridge to C35 came at a later attempt.  I was so surprised that I did it and even more surprised that I didn't notice it before testing the pod.

Looking at the brd file:
R46 Pin 1  goes something referenced N31930727 on the board
R46 Pin 2 goes to DGND

C35 Pin 1 goes to N31930727
C35 Pin 2 goes to N31930664

It looked like the short went from pin 1 to pin 1. The components are tiny so maybe I shorted C35 itself.

I also started the pod at 1200MHz - I feel kind of dumb admitting that.
I had to post my failure.  I want to focus on fixing it if I can.  Turn a negative into a positive.

ZiG - Can we put a resistor between Con3 pin3 and C38 pin1 or C40 pin1 or C41 pin1 or C43 pin1?  

Thank Amix for the helpful advice.  I'll focus on cleaning the pins for now.  The underside is clean.  

Any, all suggestions, tips, advice for what to do and what to check are welcome.

Finally somebody here, competent to verify independently  what I was posting in that thread...with clear understanding of (Gridseed ) electronics, schematics etc...

Thanks Mixdio...!

I recall now seeing your post back in March...I took a different path since the beginning...March 13 ...using trim pot to R46 to explore smoothly the DVDD voltage increase and it's effect on the overclocking performance and hashing ...Now I see also that you have been playing with VPLL...me too... and can tell that VPPL has a very positive effect on the stability and performance potential of the device...( reference google CPU PLL ...)

Back to the problem...everything is pointing to C35...the capacitor next to R46 pads...It is connected to the pin "SS" of the uP1509 - "buck convertor" / Voltage chip...I could NOT find any data or specs for this chip...but many other manufacturers have similar IC...like TI, Motorola, Panasonic etc...All of them are marking "SS" pin as "Soft Start" ...which means that it is responsible for a nice, Smooth, with NO transient transitions on the Power MOSFETs ...gradual rise of the voltage supplied to the rest of the circuitry...

C35 is connected to "SS" pin and is responsible for this function of the voltage regulator to start / function properly...IF YOU SHORT or DISCONNECT C35... in any way...the voltage regulator CAN NOT START "SOFT"...or smooth...or properly...and one could expect all kind of unwanted effects on the voltage output of the buck convertor...like clicking sound...maybe VR is trying to start...and couldn't...in cycle...I guess...
 
In both of these cases the guys reported that have been messy around C35...short or missing...or something in that matter...Sorry to hear that...

Anyway...I never had this problem so far...never have been messing with C35...and don't understand how C35 could be even touch in the process of cutting R46 bridge...there is enough space on the opposite side of C35 to use "Exacto knife"...cut gently the R46 bridge...and YOU ARE DONE...You don't need to solder anything to the pads of R46...or mess anymore in proximity with C35...

I already pointed that there is many other spots - a FULL ROW of pads to solder...with a lot of space around...PLUS a BIG GROUND PAD under them...

Again...to be able to modify / change /experiment with your electronic device(s)...a person have to...:

1. UNDERSTAND what needs to be done...and what he/she is doing...
2. Have KNOWLEDGE about the device...it's operation,... the process to be performed...and the desired/possible results...
3. TOOLS suitable to perform the job in satisfactory manner...
4. SKILLS to do it...
5. etc...

IF you are not sure that you have ALL of these above...simply DO NOT DO IT...DON"T EVEN TRY...because the results will NOT BE what you are trying ...and expecting to be...but the decision is completely up to you..

I am only trying to help...for free...on my time...but you are the one to actually do it...

Ask...research...learn first...and try later...it is NOT a rocket science...a relatively simple procedure...and one day there is a good chance to succeed...

Thanks for your time to read this...didn't anticipate to be that long...

ZiG

firstly clicking is prob the crystal i got it when i did the r52 mod with a 56k resistor. Applying slight pressure o. The crystal lessened it i reworked. It was less. I then uninstalled my grid dricers - i was getting an uart open error  - and checkdd the box to delete the drivers. Tge dud a fresh install of the drivers. It sorted it. I aslo noticed havibg several instances of grid miner software cancause issues!! Byt it ciuldve been my drivers agsin.

As for the dolder o. Your chips thats from underside of yhe gtids. It connects the thermal plate under the grids to the theal vias. This is something i mentioned way back. Appears they used eithrr normal solder and tinned the pads or too much solder paste. On mine it was leaking o. The underside on several chips i had balls o  tge thermal vias!! Try reworking it but first check the underside of your pcd make sure the thermal viad are clear. You might want to remove any dolder fro. The underside first. Hot air rework would do nicely alibg with flhx and desolder braid. To remove the doldrr balls o  top flux and desolder braid. Either hit air it and remove the balls or a very fine solder tip. Rither way you need to be carefull. Chances are you might end up unsolderi g a fws pins. Resolder them with a fine tip. Remember to applyf
 Flux to the pins beforehand and ti you tip.

Google smd remove. Theres a few you tube videos out there thatll be able to show you. It sint eady though so pratice on somethi g else first.

Dud wolfey invent the mod?? Er no wad someo e else he jyst gyessed what they wsd up to. Slthough i had the idwa of the r52 mod first. Others jyst tested it and put it into practice furst.
 When overclickibg make sure you have fan cooling and even improved thetmsl pafs/paste especailly on the u derside!!!!!

You really need to cut it out with the personal attacks. It's obvious to anyone who's been following this thread that you have some sort of personal vendetta against Zig for introducing an alternative mod. It doesn't matter if you've 'invented' the original mod, nobody likes an asshole and you're doling it out in droves.

And I've had the clicking issue as well, and I've only done the R52 mod. The only time I heard it though was when I plugged in the power to the USB hub, but not the 12V power. It went away after I turned on the 12V power. I thought it was kind of weird, but didn't think much of it at the time, and it never happened again except for that one time. All my Gridseeds are hashing away fine too, so I'm not sure what I did to cause it to click.

My devices have been running stable for over a month with R46 = 14k7.

Zig's mod looks to be the same mod I posted back on page 22. The schematic clearly shows R46 in series with the other SET resistors, and the mod should not cause any more problems than replacing R63/R64/R66/R139.

Wow! That sucks! No one has EVER had this trouble like that with the R52 mod! No One! Not even green-horns!
Shit!This really bugs me! I feel for your loss! 4 good chips ruined by yet another Zig DOH!!! pod killer mod! Are you absolutely sure un-bridging and adding a resistive load to R42 is correct, Zig? Never mind.  I strongly suspect - NOT! This clicking problem only started happening after Zig's mod was introduced!
I think that Zig's mod should be killed for now, at least until the actual cause of the clicking which most likely means something permanently serious has happened and your pod is now a paper weight, is discovered. Looks like I have my work cut out for me. Thanks Zig!
Remember, R52 (aka R139-at least he got that right) mod is proven by thousands of mods to work without harming your pod, even if you make a mistake, the worst that happens is your pod stops working until the solder connections are re-done correctly or the mod is reversed. No permanent destruction! Certainly no solder melting hot chips destruction occurs! I think this makes 4 clicking pods now....That's just too many fried pods! DANGER!
Stick with R52 mod. And again, the chances of our pods ever profitably mining SHA again are slim to none and IF the mod ever has to be reversed, it can be done easily by any qualified tech. Even greenhorns can do it in a reasonable amount of time, obviously!

Hey nst6563,
what commands did you use to get both the summary and scrolling print out? I can only get one or the other..DOH!
Tanks!

I tried rmod on a second gridseed today after having it working well on another gridseed for several days.  This one already had vmod1 and I was adding 15k.  Actual measured numbers were 35.83k + 14.92k = 50.75 tested on board.  That is on the high side I know.  
I got the clicking noise and tried to redo a few times but couldn't solve it.  I'm not good at soldering but thought I did an ok job. Voltage was low on first try 1.3 something.  Second try had the voltage at 1.63v.  I removed vmod1 but the clicking was still there.  You can actually feel the clicking.  The first pod I did had a higher value large silver capacitor 16v 330.  This pod has 16v 220.

I screwed something up though on one of the later tries. I may have bridged to that 20nf capacitor.  It got hot quickly ..... some solder has actually come out from under one of the gc3355 chips on two sides!     These little things are pretty tough.  One chip of the five is still working so hopefully I can fix it up.





Summary:
rmod removed, bridge replaced, no clicking sound
It powers up and miner software sees it.  cpuminer reports 5 chips and sets the frequency.
Only one chip does any mining and those shares are accepted by pool. (only chip #4 works)
Red light blinks very very slow.  It can be off for a long time or on for a long time. This might be caused because only one chip is actually mining.
Solder is visible on two sides of the center Gridchip (one of the mining chips).  See photo.  It covers four or five pins on one side and maybe three on another side.  I did not drop solder there and I know it wasn't there earlier because I took a photo of the new resistor in place before trying it.  I think it has come out from under the chip if that is possible. How do I remove that?  

I need some advice or suggestions on what to check / what to do so I can try to recover it or at least get a few more chips working.  Any help will be greatly appreciated.

k, thx. I see scrolling now but no summary at the top anymore.. Can I get both to work at the same time? I thought that was the idea.
Also, I see only 2 colors. No reds and greens like in the previous versions....why? I presume pod autotune is ON by default?
thx!

so if we just use



it sets the speeds per pod right?

Holy Shite!  talk about a typo...whoa...

Be careful with that. 

Here is the command line (Gridseed speeds are set within it)

I just launched it with the parameters you specified, let it run for a few minutes but then it just froze.  
Here's the log:
https://www.dropbox.com/s/jj1yneqjcrstr81/cpuminer-gc3355.log

:EDIT: If I remove the --log parameter it doesn't freeze.  When I add it back in, it freezes after just a minute or two.
System specs:
Asus P8z77v-pro
Core i-7 IvyBridge @ 4.55Ghz
24GB DDR3
5-disc RAID with SSD acceleration

I'm using this syntax

minerd-gc3355.exe --gc3355=\\.\COM7,\\.\COM8,\\.\COM9,\\.\COM10,\\.\COM11 --gc3355-autotune --freq=1150 --url=stratum+tcp:/xx:xx --userpass=xx.xx:xx