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T7500 won't turn on
Hello,
I could not turn my T7500 on as when I pressed the power button, nothing happened, no light nothing. So, I disconnected the power cord from PSU to motherboard and test with BIST function and the light at BIST flash. However, when I reconnected the line back, nothing happened when I pressed BIST button. Can I confirm that this is the motherboard problem or is there still other possibility of the failure?
At this point, I think I will try to replace CMOS battery with the new one. If that doesn't work, I will order the motherboard from ebay. Any idea?
Thanks a lot,
Roytor
JOcean
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June 15th, 2019 08:00
It could be the motherboard but the only way to test a PSU is to try another PSU. A PSU may seem to test fine but under load may fail. I would go PSU first being the easiest and cheapest.
Roytor
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June 19th, 2019 16:00
Thanks a lot. Today we tested the PSU with PSU tester and it worked fine. So, I think the problem is the motherboard, however, would it be something else on the board like CPU?
Also, today I tried to replace the new motherboard. Unfortunately, I could not access the screws under the dual processor riser. Could you advise how to remove that.
bradthetechnut
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June 21st, 2019 18:00
T7500 Service Manual
T7500 Tech Guide
You'll find removal of the riser in the service manual. It has links that will get you right there. Adding or replacing parts > Dual processor riser
bradthetechnut
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June 21st, 2019 19:00
I believe you would get a diagnostic light code if it were the CPU. Codes are also in the service manual.
speedstep
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June 25th, 2019 22:00
BIST is not diagnostic for motherboard.
BIST Light Should not go out.
If it does your power supply is bad.
_abednego
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June 27th, 2019 12:00
No, BIST LED not turning on does not mean the PSU is bad. It means there is something inside the workstation that causes a power failure, and nothing more. Please, take a loot at this video from TechSupportDell to understand how this feature works and isolate the component that makes the power fail on the workstation.
scraprion
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October 19th, 2020 08:00
Having same issue.
I replaced the motherboard and everything seemed back to normal. Went on a trip for a couple of weeks, shutdown the T7500, but still plugged into the mains, just tried to start it and it's dead. Nothing.
If I disconnect the main motherboard supply, the PSU BIST is green (while pressed).
I have disconnected everything from the motherboard (RAM, riser card, all SATA drives, video cards, network cards, USB devices, CMOS battery, ethernet).
Could it be a bad PSU? Bad PS cable?
bradthetechnut
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October 20th, 2020 18:00
"If I disconnect the main motherboard supply, the PSU BIST is green (while pressed)." Does this mean no green light with the MB plugged in, and only the MB?
Miggarti
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October 21st, 2020 10:00
It is may be a piece of hardware block the power on to protect the motherboard. I suggest to remove any hardware in T7500. You will see after if you can power on this big tower.
bradthetechnut
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October 21st, 2020 17:00
How old is the CMOS battery?