Unsolved
This post is more than 5 years old
2 Posts
0
1322
October 25th, 2018 15:00
Optiplex 790 SFF, PSU BIST passes
My unit will not power on with the front button at all. When I press the BIST, the light comes on green. I have no other numbers or lights flashing anywhere. Suggestions?
No Events found!
fireberd
11 Legend
•
33.4K Posts
•
112.8K Points
0
October 26th, 2018 07:00
I've been on this forum since 2002 but I have no idea what "BIST" is. Please explain.
Also which specific 790 do you have? There are many versions, Small Form Factor, Mini Desktop, etc. Always include the version you have with any initial problem post.
Bigjimmylaw
2 Posts
0
October 26th, 2018 07:00
I am referring to the built-in test button that is on the back of the power supply. Also it is a small form factor. what
fireberd
11 Legend
•
33.4K Posts
•
112.8K Points
0
October 26th, 2018 12:00
Four possibilities.
1. Bad Power Button
2. Bad power button connection from the front panel to the motherboard.
3. Bad 24 pin power connector from power supply to motherboard.
4. Motherboard problem.
You can eliminate 2 and 3 by reseating the connectors. Reseat - 1. with the PC powered off, open the case and locate the front panel connector. Remove (unplug) the connector then plug back in making sure its fully and correctly plugged back in. Try to power up. If it powers up, the reseat fixed it. If it doesn't power on, reseat the 24 pin connector. Try to power on.
If it still does not power on you can jumper pin. If it powers on the motherboard is at fault and will require replacement. If it does not power on with the Jumper then the power supply is the problem, even though the self test passes.
Here is a procedure for the jumper from the Green wire to any Black (ground) wire. Its for a different purpose but it details the green/black jumper.
https://www.instructables.com/id/How-to-power-up-an-ATX-Power-Supply-without-a-PC/