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viewtopic.php?f=3&t=10849Obelix wrote:
Thanks to anyone who gave me informations and advice!
Just a final note to let you people know the end of the story of my broken Fuel PSU. Remember that I had the +5V line gone up to +6V, causing the machine to auto-shut down. Other voltages were right.
Eventually, it was impossible to adapt a normal ATX power supply to the Fuel, not because of the differences in the connector pinout nor because of the insane current requirement for the +3.3V line, but because the environmental monitor *needs* a feedback signal from the PSU fan, a thing that no ATX power supply ever had. No signal means fan failure, which means auto shut off.
So I did what I should have done from day one – I had the PSU serviced by a competent technician.
It did cost me *a lot* of money, yet just a fraction of the 550$ that a well-known supplier of SGI spares charges for a new PSU. The culprit was a single IC that with its different sections individually controls each of the four voltages.
The technician went lyrical about the excellent design and the build quality of the power supply – and with good reason. Once repaired, all voltages remained constant within a few millivolts, even under extremely unbalanced loads (25 Ampere from one line, zero from the others).
I put the PSU back at work and closely monitored its behaviour for the first three hours, and all voltages remained rock-steady up to the second decimal digit. The only changing figures were the speed of the fans and the temperature of the chips. Apparently, nothing was damaged by the previous over-voltage.
And (hopefully) that’s all, folks!