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May 21st, 2025 00:20
T7500 PSU no power - mobo inquiry
Was told on bootup message error for DIMM6, then F1 and it went through. This evidently happened for a week.
Then it would only boot if the PSU tester button was pressed then the front power button.
Now it won't boot at all.
Have isolated the PSU from everything and when the 15 and 16 pins are connected on the 24 pin ATX, the PSU light is green and it runs okay.
Once the ATX is connected back to the mobo, it doesn't work, no mobo light.
Disconnected all drives.
Have taken out the CPU 2 riser, all Dims except #1 on the mobo and still no power.
Have disconnected CPU 1 power, front panel power and still no power.
Not sure what next to do.
Any ideas what it may be please?
Because the PSU works with the pins 15,16 connected, does that mean it is okay? If so, seems like it's the mobo.
Any definitive test to see if it is?
Thanks
ozstar
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May 21st, 2025 04:41
To add to the above, I have just multi tested the ATX 24 pin with the PSU on and the voltages are as recommended.
So am I back to the mobo?
Is there anything else that could cause to not boot up ?
JOcean
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May 21st, 2025 18:13
@ozstar If you press the PSU BIST button and the PSU lights green and the PSU fan runs then the PSU is working properly per Dell specs. What can cause your problem then? Bad DIMMs, bad CPU, bad MB, If you have disconnected everything from the PSU except the MB and still get no power then try removing all the DIMMs. You should get an error but some response. Have you tried jumping the power switch connection on the MB just to rule out the power button? One thought though, have you tried replacing the CMOS battery with a brand new recently purchased battery? If you replace it remember to leave the old battery out of the system for 15 minutes before installing the new battery.
(edited)
ozstar
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May 21st, 2025 22:13
Many thank for the suggestions. I tried them all and still no sign of life except the mobo light goes on whenever I plug the power in. Other than that.. dead evene when I press the PSU BIST in.
As I said The PSU does work with pins 15-16 joined.
I am at a loss as nothing else in plugged into the mobo.
JOcean
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May 22nd, 2025 01:23
@ozstar Sure sounds like a bricked MB. eBay Canada (probably US as well but I am a Canuck) shows a number of MB at this link.
ozstar
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May 22nd, 2025 21:25
Thank you.
I found one in Western Australia.
I am in Sydney Oz 4 ks away but better than having to get it from C or US. Its the postage that kills it and our dollar is trash at the moment. :-(
Anyway hope we can getit up and running again soon.