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Bitcoin => Mining support => Topic started by: Matce on March 25, 2021, 09:56:16 PM



Title: PSU problem - need some "insider" info
Post by: Matce on March 25, 2021, 09:56:16 PM
So I have a few chinese Q3 miners (similar to A1, F1, etc) - one of the miners popped a PSU. I found a exploded MOSFET, replaced it, no luck.

From my understanding the PSU has 3 inputs/outputs. The output for the control board still works. The high-power output to the hashboards is dead and there is another input or output (4 wires, separate connector from control board) that I can't identify.
I'm ASSUMING its some sort of control for the PSU to turn on/off/PWM/??? hashboards.

Wondering if I can just get a separate high-power PSU and feed the hashboards from that. The broken PSU can still supply the control-board (or just run it from new PSU as well)?

Anybody knows how controlboards/PSUs interact?

Out of the 4 wires, I got 1 ground, 2 voltages (3.88) coming FROM the PSU and 1 voltage (3.3V) going to the PSU.
When I unplug the connector (on another miner) the miner powers down because it can't read temperatures of chips and also a LED goes on/off.
So I'm figuring: 3.88V is the power supply for the temperature-measurement circuits (1 circuit for 2 chains, so 2 wires for 4 chains) and the outgoing 3.3V is the LED?

Would mean I could run the miner on a "regular" PSU with a step-down for 3.88V for the temp-circuit?

thanks


Title: Re: PSU problem - need some "insider" info
Post by: NotFuzzyWarm on March 26, 2021, 04:37:45 PM
Perhaps, but only if you know what voltage the hash boards run at. These days that can be anywhere from 14vdc up to 23vdc.

One of the lines from the controller to PSU should be a control signal that adjusts the hash board vdc output to what the controller commands.


Title: Re: PSU problem - need some "insider" info
Post by: philipma1957 on March 27, 2021, 12:32:28 AM
@op this is simple case of planned obsolescence.  Once your bespoke PSU dies and the builder no longer sells that model your gear becomes a brick.

Builders learned their lesson from the s9 and now have stopped making easy to replace PSU's.

Good luck finding a replacement.


Title: Re: PSU problem - need some "insider" info
Post by: o_solo_miner on March 27, 2021, 09:13:33 AM
It would be helpfull to include some pictures from the dead psu, so we can see a bit more.

The 3.88V could be anything, without knowing the origin of it. The Mosfet need a negative voltage (or a negative offset) so you should begin to draw some sort of schematic for fault finding.