Quote from: RichBC on November 10, 2015, 06:30:18 PM

Quote from: Questor on November 10, 2015, 06:13:39 PM

Quote from: jtoomim on April 24, 2015, 07:34:57 AM

Does anyone here know what the component labeled "G337 V2" on the Antminer S5 hashboards is? It's a 2-pin package, looks to be built for high current, and is silkscreen labeled C2, C3, etc. There's one in between each pair of ASICs -- i.e., one for each stage in the string, shared by both strings. My best guess is that they are shunt voltage regulators intended to serve as a bypass in case the voltage gets too high (dead ASIC?), but I don't really know. Ideally, if someone at Bitmain could chime in with a link to a datasheet or a part number, that would be ideal. We're investigating an issue on behalf of another miner in which some of them appear to have burned out.

Has anyone managed to effect a repair on hashboards where this part has burned?

I have in front of me an S5 which obviously burned in this manner, on each hash board the third (R to L on top row) 2v 330uf cap is burned to white powder on top, and on one of the boards the second one has started to go as well. I'm also measuring low resistance on the 4.99 Ohm Chip resistor above each of the badly burned caps but the resistor on the half burned capacitor is testing nominally.

Any other components to check before replacing the caps / resistors? It seems that if a 2V cap fried this badly, there surely must be damage to the ASIC pair around it, but perhaps these are miracle boards...?

Anyone who has worked on these please chime in with any thoughts or advice.

Cheers!

P.S. if anyone has digi or mouser part #'s that would be great. I saw J4bberwock posted a 4v part which should be fine, but if anyone has the exact #'s it is appreciated!

The cap is fried, however most likely it has fried because of a failure of one or both of the BM1384 ASIC chips on the Node. Dependant on the exact mode of failure of the BM1384 the 2V capacitor will have been overvolted causing failure. Measuring across the capacitor / resistor should read about 4.7 Ohms (Do allow for resistance of the meter leads by connecting them together before measuring)

So you can try replacing the capacitor but almost certainly one or both of the BM1384 chips will also have failed. Changing them is much more difficult.

Rich

Thank you for the reply! So, I replaced the capacitor, but the board still does not hash Sad

All ASIC's show 'oooooooo' in the status, but the hashrate is zero, I would have expected to see oooo--oo or ooooxxoo or whatnot...

Is there a way to bypass what may be the dead ASIC's without overly affecting the rest of the chips / voltages on the boards?