Topic: S17+ Chip repair questions (Read 208 times)

Another example: In his guide, he talks about the PIC reprogramming. I have a hashboard here that showed 2.5V on the second pin. He said if it's not at around 3.3V, you should reprogram the PIC. I ordered me a PICkit 3.5, ordered the HEX files from ZEUS, I did everything step by step and reprogrammed the PIC, now I got it at 2.8V. So still no 3.3V. But in the guide, it stops there. What if the reprogramming doesn't do the thing? Should I replace the PIC? Or does it mean I need to look elswhere for the problem? It's not that the PIC doesn't show anything. So if the PIC was bad, it would probably show 0V or am I wrong?

Oh I figured that out meanwhile. It's just because his explanation in English can get a bit confusing. He was talking about the output voltage and in the same sentence he said to measure the resistance. That's what confused me. His guide might use a better translation though, many confusing parts in the whole thing, but I'm managing to manouvre myself out of it. I just took a working hashboard, measured the whole thing out, and wrote the data down to compare to the malfunctioning boards. I'm getting there eventually
PS: I'm an industrial electrician, so the basic knowledge is more than present, just need to school myself a bit more in to electronics

This is technical and it seems you don't have knowledge about repairing boards.

It's not measuring the voltage it's measuring resistance like the capacitors(The orange/brown color) for me with an analog multimeter I don't use exact Ohms if I see there is resistance on both polarity then I'm sure it's shorted but if you see no resistance then the capacitor is not shorted. Another thing to find those shorted parts in my own experienced is by injecting voltage and find what parts are hot.

In that case, you need to point the multimeter at the ground(The positive one) and the pins from 1,4, and 8(The negative one) to check if those MOS are shorted.



Without any knowledge about the basic repair, you will not understand the guide from ZeusBTC. You should learn the basic repair first

About your first question, since the image said downward then from the image, you need to start from 1 which is the first pin on the top left corner, and the 4th pin is on the top right corner then the 8th pin bottom right corner.

Like for example on ZEUS's explanation in the picture below. He talks about measuring the resistance between pins 1,4 and 8.

First question: which ones are the pins 1, 4 and 8 exactly?
Second question: Measuring the resistance? Or does he mean measuring the Voltage? If not, what should the resistance be exactly in Ohms?

EDIT: Found quite some information through the chip datasheet in link below:
https://toshiba.semicon-storage.com/ap-en/semiconductor/product/mosfets/12v-300v-mosfets/detail.TPHR9003NL.html

I've been doing nothing but youtubing
The thing is, many of these tools are explained for different applications other than asic mining.
It's quite confusing. The measures are much different and it's much more helpful to get the info from technicians who are familiar with mining gear.

There is very little information online when it comes to asic repair. So my best guess is to get help here

I never heard of this tool but it looks like a tool that could use for testing and reading a logic board or it's more likely a debugging tool the same as what test fixtures do.

I would suggest you search it on youtube to see how it works.

I'm sorry I just noticed there were comments on my topic.
Thank you for the expanded explanation.

How does the I2C analyzer work exactly? What does it do?

Yes, its fine flux is enough solder paste only needs if you see the terminal doesn't have enough solder, or if you can't easily solder the chip you will need a bit of them.
But it is still recommended to add a bit of solder paste to make sure all terminals from the chip are soldered.

i saw a video on youtube how when replacing a faulty chip under a new chip they don't put some tin paste and they put it in place with a little flux and load it.
And it all works.
It's fine?

Perverza nailed all the key points and Merit given for that

All I'll add is a couple corrections in terminology:
It is not 'rust' between the pins nor is it any other sort of normal corrosion. What you see are called tin dendrites, fine metallic tin crystals that grow out of the solder from the combination of moisture in the air and electrical fields. While they have always been a potential issue where there are bare closely spaced solder connections it wasn't until lead-free solder was forced into use that it became serious - the main reason that Lead was added to solder back in the late 1930's was to prevent formation of dendrites. Lowering the melting point of the solder alloys was just icing on on the cake. Nothing has yet been found to prevent dendrites that works as well as Lead being part of the alloy does. FYI that is why Leaded solder is still permitted for medical, aerospace, military, and some industrial devices/circuits where that preventable failure mode is out of the question.

Soapbox time: The issue of leaded solder being an environmental hazard is pure bullshit. Even after disposal into landfills vs being recycled, consumer devices using leaded solder has never been shown to be a significant contributor of lead in the environment. The result of lead-free solder causing faster failure of devices however IS significant. Even with recycling in place more electronic gear is being tossed out as garbage than ever because it dies far sooner than it could work.


The other is 'Supersonic'. Supersonic means faster than the speed of sound. That is an ultrasonic cleaner which uses very high frequency sound waves far above what people can hear (usually between 25kHz up to 500kHz is used) to create cavitation bubbles on the surfaces the sound waves hit.

Hello,

1. You need low solder paste. for example Bismuthum+Sn (Sn42Bi58).
2. You need very,very,very good bench multimeter, best to use is the 4-wire method or you can buy somewhere miliohm meter. I use keithley 2000 .
you can measure resistance between chip 1,8Volts, is it best method for found cold solders for me, but you need very good multimeter/miliohm meter.
3. You can use I2C analyzer, or change sensor and asic chip which is connected to the sensor.
4. Be careful with supersonic bath, tin is very fragile because bitmain use low solder paste. You can make more cold connections between chip and board.
I use PCB cleaner and little antistatic brush

M.

Hello

I have a bunch of S17+ hashboards piled up for repair and I've been keeping busy with figuring out as much as I can. Sadly for technicians that like to do everything themselves like me, there is not much detailed info out there on this issue. Most info I found were in Russian or some other foreign language I couldn't understand.

So to repair my hashboards I'm left with a few questions I hope you guys can help me out.
I'm an electrician myself and I have quite some tools in my workshop so that's not really an issue.

1) Until now I used the black bitmain glue to stick the heatsinks back on, but I found that the chips with the glue got hotter. Now I would like to try using soldering
    tin to fix the heatsinks back on the chips. Can anyone tell me exactly what tin I need to buy?

2) How do you guys figure out which chip exactly is malfunctioning? I got a voltmeter, I got the Zeus test fixture (but in an earlier topic a few people told me that
    test fixture is practically useless as it keeps turning off the hashboard). Is it possible to measure the malfunctioning chip by resistance? If so, does someone
    know what resistance in Ohm every measuring point needs to be approximately? Or is the only way to measure by voltage and powering on the hashboard?

3) I also see a lot of Temperature sensor errors. But sadly can't find a lot of info about how to measure it. How can I measure the temperature sensors?

4) I often use my Supersonic bath to clean the hashboards, as I find a lot of times the chip legs rusted and bridged together, this way helps a lot to get
    them nice and clean, but the heatsinks usually fall off when I do that. Does anyone know if they sell a heatsink template for hashboards so we could glue/solder
    the heatsinks much faster on the hashboard? Been looking all over google, but can't find anything. I'm thinking of buying an aluminum 3d printer just to make
    that now...


Thank you guys for responding!