Antminer S9 Chip Repair Questions

[eotrix]

Hello, I have watched some videos that guides you to detect faulty chip and replace them. First they use Fixture app and then confirms with Multimeter and here I have issues. I have a question I wonder. Do we test resistance values with multimeter while board has power or no? Also, can we directly use multimeter to check 63 ASIC without Fixture test to find faulty chips?

Im asking about that because for example a guy gives table for resistance values and when I check with my multimeter I get like way lower values for every asic. His table says 780 and I get 360 for CLK on every Asic. But I do test them hashboard power off. So if anyone have more insight and even some more tricks about this detect and repair process, I would be appreciated.

Thanks

[NotFuzzyWarm]

Unless specifically instructed otherwise, resistance measurements are ALWAYS done with power off.

That said, depending on make & model multimeters can apply different voltages when doing resistance checks and that will affect what you see: if they use a very low voltage then semiconductor junctions may not turn on vs a meter that uses a higher voltage. That will definitely change your readings.

Best thing to do is take a set of measurements on a known good board and use those readings as your reference.

[eotrix]

Thank you for the reply sir. I have took my time and measure all the chips' resistances and found out one of them shows x2.5 higher than rest. So I assume that one is the failure chip on board.