S7 Hash Board Tech Info

[flameruk]

Hi.
Does anyone have a layout showing the ASIC order for an S7 hash board.
So for example in the GUI if the third ASIC shows X which physical chip it relates to.
I've never seen past the heat sinks on a board yet so I guess the chains and chips could be on the legend.

I've got some partiality dead cards coming my way so just starting to prepare to lift and swap some chips to try and repair some hash cards. I had a good success rate on the old SP20's when I was doing them.

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[NotFuzzyWarm]

Well good luck with replacing s7 chips. Per Sidehack the combination of the heatsinks being glued to the top of the chips and the very-fine lead pitch all but makes cleanly removing/harvesting/reusing s7 chips near impossible. You better have one heck of a pre-heater for the boards and good hot air tool to pull the chips.

Do please let us know if you are successful!

[flameruk]

Well good luck with replacing s7 chips. Per Sidehack the combination of the heatsinks being glued to the top of the chips and the very-fine lead pitch all but makes cleanly removing/harvesting/reusing s7 chips near impossible. You better have one heck of a pre-heater for the boards and good hot air tool to pull the chips.

Do please let us know if you are successful!

Will do.
Luckily I have a very nice rework station in our electronics lab and a set of keys.
The Spondoolies SP20s were very awkward to do as the ASIC chips came on a sub board so I'm hoping that these are a little easier.

I can see the problem of getting rid of the heat sinks without pulling tracks from the board though.
One card I have coming is partially burned so I've got some practice on that one.

Wounded if sidehack has any ideas of the ASIC layouts might drop him a PM.

Probably be Christmas when these boards arrive so I'll get some pictures up when I'm working.
Then I'm going for it and going to repair a working miner.

[sidehack]

Topside heatsinks can be removed with hot air to soften the epoxy. White epoxy will dissolve in acetone, not sure yet what cuts the black epoxy. Different epoxies were used on different batches.

As for layout, not really sure offhand. I'll check something over and might post a picture later.

[flameruk]

Topside heatsinks can be removed with hot air to soften the epoxy. White epoxy will dissolve in acetone, not sure yet what cuts the black epoxy. Different epoxies were used on different batches.

As for layout, not really sure offhand. I'll check something over and might post a picture later.

Cool Sidehack, any help would be great.

I might try some de-potting agent on the black epoxy im sure we have a few gallons left here from when we were repairing some weatherproof control boxes.
As for the white, Ill pull the home made sandwich toaster hot box out and cook the boards in that for a while see if that softens them.
I dont really want to bugger up the pre-heater with dripping epoxy as my boss might not be to happy about that.

Ill have to cook up another batch of acetone with some epsom salts to remove the moisture from it so I have no moisture involved.

If you have anything on the ASIC locations that would be a bonus or its gonna be a few long days of track tracing to work it out.
I have the data sheet on the ASICS so hopefully the chained data bus is an external layer on the board, but more than likely hidden away inside some place.

Thanks!

[sidehack]

Hot air and a bit of pressure worked just fine for me on heatsinks, but then I don't have fancy tools.

Once the chips are clean it shouldn't take half an hour to figure out the routing. Just by looking at how the ground/power planes interact you can figure out node spacing. S7 won't be as easy as S5 since on the S5 the diode level shifters pretty much gave away where the inter-node data connection was but S7 chips integrate level shifting so it's pretty much just traces from chip to chip.

You looking at a 54-chip or a 45-chip?

[flameruk]

Hot air and a bit of pressure worked just fine for me on heatsinks, but then I don't have fancy tools.

Once the chips are clean it shouldn't take half an hour to figure out the routing. Just by looking at how the ground/power planes interact you can figure out node spacing. S7 won't be as easy as S5 since on the S5 the diode level shifters pretty much gave away where the inter-node data connection was but S7 chips integrate level shifting so it's pretty much just traces from chip to chip.

You looking at a 54-chip or a 45-chip?

54's sir. I have early batch Miners and those are the ones I want to keep going for a little longer.
I'm 50/50 just to scrap the lot but I'm still profitable at the moment.
I spent a lot of time working on the SP20's but then they only had a couple of chips per board.

I need to spend some time on the Bitmain gear now to learn it's inner workings then I rekkon I can move onto the S9 hash cards next year.

Thanks for the reply.

[sidehack]

Unfortunately I don't have a stripped-down 54-chip board anymore, just some functional ones I don't really want to take apart.

[flameruk]

Unfortunately I don't have a stripped-down 54-chip board anymore, just some functional ones I don't really want to take apart.

Cool, I'll gladly share my findings with you real soon.
I'm waiting on 5 cards to arrive.