Topic: Capacitor repair on an Antminer S1 board? (Read 7077 times)

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

It is very well possible these were 'NOPOPs',
parts that were not ment to be populated
on the board.

Sometimes after testing a design, it turns
out some parts can be omitted without
decreasing the performance of the circuit.
Parts are then not placed during production
in order to save a few bucks.

When the solder on the pads looks nice and
regular, there were never caps on that location.

I don't think they should be DNPs, as they're the output caps for the buck regulator (the same part (TPS5335) you used on the Bitfury 25GH boards).

If anyone's interested here's the relevant schematic section.

Edgar: from what I've seen the heatsink compound used is of passable quality - the actual application during assembly varied wildly (too much, too little). The HS screws were also installed erratically, resulting in voids under the heatsink where no or little contact was made. I also had several where cutting/tapping fluid (which hadn't been cleaned out properly) oozed out from the heatsink screw holes and mixed with the compound, resulting in a runny mess.

Don't get me started on the HS design itself..

comparing the designs, the Bitfury design only has 500uF in bulk caps(ceramics), while bitmain rev.1 has 3000uF in bulk caps(electrolytic) and Rev.2 has 1500uF

the purpose of the caps at the output is to smooth the voltage to as much of a flat line as possible by providing a resevoir to fill the valleys in the mV_p-p

SLEI

member

Activity: 84

Merit: 10

Any idea of capacitor C302 specs that one is missing from year 2014 version 1.6 board?

Near by C152 was also broken from one end.

Bitmain don't give any specs, miner is working but parts are propably needed.

jimrome

sr. member

Activity: 434

Merit: 250

Quote from: togame on June 07, 2014, 05:53:38 PM

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

It is very well possible these were 'NOPOPs',
parts that were not ment to be populated
on the board.

Sometimes after testing a design, it turns
out some parts can be omitted without
decreasing the performance of the circuit.
Parts are then not placed during production
in order to save a few bucks.

When the solder on the pads looks nice and
regular, there were never caps on that location.

I don't think they should be DNPs, as they're the output caps for the buck regulator (the same part (TPS5335) you used on the Bitfury 25GH boards).

If anyone's interested here's the relevant schematic section.

Edgar: from what I've seen the heatsink compound used is of passable quality - the actual application during assembly varied wildly (too much, too little). The HS screws were also installed erratically, resulting in voids under the heatsink where no or little contact was made. I also had several where cutting/tapping fluid (which hadn't been cleaned out properly) oozed out from the heatsink screw holes and mixed with the compound, resulting in a runny mess.

Don't get me started on the HS design itself..

edgar

legendary

Activity: 1848

Merit: 1001

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

It is very well possible these were 'NOPOPs',
parts that were not ment to be populated
on the board.

Sometimes after testing a design, it turns
out some parts can be omitted without
decreasing the performance of the circuit.
Parts are then not placed during production
in order to save a few bucks.

When the solder on the pads looks nice and
regular, there were never caps on that location.

I understand that, however this unit does not perform as intended, which is why I contacted bitmain. This unit runs quite well for a few hours then performance decreases to a seemingly arbitrary rate. I've had it perform anywhere from 9 to around 140 Gh/s. The only way for me to fix this is to cycle the power.

yea but.... think how many whole cents Bitmain saved.

doesnt it seem worth it now?

Even with all components in place & functioning correctly, i imagine the thermal paste under your s1 blades could well be retarded/ineffective.

IF its even thermal grease...it might just be old engine oil mixed with fake baby milk powder!

Still - waste not, want not!

togame

newbie

Activity: 6

Merit: 0

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

It is very well possible these were 'NOPOPs',
parts that were not ment to be populated
on the board.

Sometimes after testing a design, it turns
out some parts can be omitted without
decreasing the performance of the circuit.
Parts are then not placed during production
in order to save a few bucks.

When the solder on the pads looks nice and
regular, there were never caps on that location.

I understand that, however this unit does not perform as intended, which is why I contacted bitmain. This unit runs quite well for a few hours then performance decreases to a seemingly arbitrary rate. I've had it perform anywhere from 9 to around 140 Gh/s. The only way for me to fix this is to cycle the power.

intron

sr. member

Activity: 427

Merit: 251

- electronics design|embedded software|verilog -

Quote from: wpgdeez on June 05, 2014, 12:08:40 PM

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

It is very well possible these were 'NOPOPs',
parts that were not ment to be populated
on the board.

Sometimes after testing a design, it turns
out some parts can be omitted without
decreasing the performance of the circuit.
Parts are then not placed during production
in order to save a few bucks.

When the solder on the pads looks nice and
regular, there were never caps on that location.

faetos

hero member

Activity: 744

Merit: 514

gotta let a coin be a coin

I didn't pack one well when I moved and broke two of those off one board. It's been running well for over two months now. I don't OC it and haven't seen any adverse effects from the two missing parts.

togame

newbie

Activity: 6

Merit: 0

I recently received an S1 which is missing a cap from every pair. It looks like they were just never there. I still haven't heard back from bitmain yet. Does anyone know where we can purchase replacements? As close to these as possible is preferred.

https://i.imgur.com/lj274W7l.jpg

edgar

legendary

Activity: 1848

Merit: 1001

i also have recently received and S2 with broken & missing caps.

had exactly the same struggle trying to get bitmain to comprehend the situation.

dozens of messages relayed and he almost always says , try it again, reseat it, off & on, try again, dont worry - try again.

i have already seen images of exploded caps and the resultant non assistance.

as it happens my rig is running 9 0f 10 blades seemingly fine but it will live its life outside, im not risking my wooden house catching on fire so bitmain can save 0.01 dorrar worth of caps & 2 dorrars worth of thermal paste....

Disgusted.!

but hey....moar coupons....ffs!!

klondike_bar

legendary

Activity: 2128

Merit: 1005

ASIC Wannabe

the S1 will run fine without that capacitor, but you may need to treat it special in order to get it to power up okay.

1) power up unit normally.
2) if there are a few non-working chips (there likely will be), reboot the miner but leave the PSU on
3) the miner will reboot and the power will be stable enough in other capacitors that all the chips read up fine.

I have a unit missing that cap (i found it in the box after) and its running fine stock without doing any repairs just using the above method

GigaWave

full member

Activity: 239

Merit: 250

Quote from: GigaWave on June 05, 2014, 10:51:11 AM

Any luck with Bitmain helping you? I had one explode, looks like wpgdeez'z below. Except it was the cap under the 12V+ header.(One farthest left in the below picture) Funny thing to is, it was the same side of the miner. IE, the side opposite the control board.

Still haven't found the cap cover. Sure did give off a nice spray of sparks.

Quote from: wpgdeez on June 05, 2014, 12:08:40 PM

Heres what you don't want your cap to look like ...

They gave me an RMA number for their account with UPS and UPS didn't know what I was talking about. I haven't bothered fixing it, maybe i'll get someone to solder on a new cap and see if it will hash again. Not sure what caused the CAP to pop, I would think some other underlying issue.

Yeah, I would like to know more about them. As in exactly what they are doing.

In my case I had a power outage and the PSU did not come back on. Unplugged and replugged the mains power about 3-4 times within about 15 seconds trying to get it to power back up. On the final try the cap popped. I removed power from the one blade and everything powered up fine. Still no idea what the issue was.

Airwhale

full member

Activity: 221

Merit: 100

I've repaired two antminers with caps that broke, one due to an accadent when moving an S1, the other due to a return from shipping damage when I ebayed the miner. It's a really easy repair. I agree that bitmain should probably just issue a refund/ ship you another blade. But, If you take the antminer to any good electronics store, they should be able to walk you through the steps. Or if you are in the San Francisco Bay area, shoot me a PM and I'll do it for you over the weekend. =)

While you are figuring this out, btw, there is no reason not to have to other blade plugged in and earning for you.

uhoh

hero member

Activity: 742

Merit: 500

Circle gets the Square

Quote from: GigaWave on June 05, 2014, 10:51:11 AM

Any luck with Bitmain helping you? I had one explode, looks like wpgdeez'z below. Except it was the cap under the 12V+ header.(One farthest left in the below picture) Funny thing to is, it was the same side of the miner. IE, the side opposite the control board.

Still haven't found the cap cover. Sure did give off a nice spray of sparks.

Quote from: GigaWave on June 05, 2014, 10:51:11 AM

Heres what you don't want your cap to look like ...

They gave me an RMA number for their account with UPS and UPS didn't know what I was talking about. I haven't bothered fixing it, maybe i'll get someone to solder on a new cap and see if it will hash again. Not sure what caused the CAP to pop, I would think some other underlying issue.

It'll probably be a pretty cheap cap that's being run too close to rating. Any TV repair shop will be able to fix this for you, the traces are intact, should take them a few seconds and cost virtually nothing. Better still though, if there is not many of them, have them all changed for a higher voltage replacement.

EDIT: If you get a replacement yourself, make sure its marked 'Low-ESR'.

wpgdeez

hero member

Activity: 728

Merit: 500

Any luck with Bitmain helping you? I had one explode, looks like wpgdeez'z below. Except it was the cap under the 12V+ header.(One farthest left in the below picture) Funny thing to is, it was the same side of the miner. IE, the side opposite the control board.

Still haven't found the cap cover. Sure did give off a nice spray of sparks.

Heres what you don't want your cap to look like ...

They gave me an RMA number for their account with UPS and UPS didn't know what I was talking about. I haven't bothered fixing it, maybe i'll get someone to solder on a new cap and see if it will hash again. Not sure what caused the CAP to pop, I would think some other underlying issue.

uhoh

hero member

Activity: 742

Merit: 500

Circle gets the Square

Should be a straight forward job. Should be able to find this in pretty much any electronics store. Though if they're popping this easily, might be better to replace them all with 5V caps.

GigaWave

full member

Activity: 239

Merit: 250

Any luck with Bitmain helping you? I had one explode, looks like wpgdeez'z below. Except it was the cap under the 12V+ header.(One farthest left in the below picture) Funny thing to is, it was the same side of the miner. IE, the side opposite the control board.

Still haven't found the cap cover. Sure did give off a nice spray of sparks.