dc7900 SFF won't start with OEM P/S. Will start with generic ATX 24 pin.

[LADave]

Green LED lit inside on motherboard, but no external signs of life when I press power on button with OEM PC6019 power supply installed.  When I swap in a generic ATX P/S, it complains about no fan connection, but starts normally and I can get to the setup screen with no drives attached.  Using this generic P/S, I've also successfully booted to MS-DOS via USB and flashed the BIOS up to version 1.27.   

Nevertheless the OEM power supply gives all greens attached to my cheap eBay P/S tester.  When I connect it to a bench power supply adapter, 3.5, 5 and +/- 12 volts all check out measured with my DVM, except +3.3 is ~7% high and  +5 is ~5% high.  Ripple is .01 volts or less.  I have not applied a serious load to stress-test this P/S.  Are there any fixes short of repair/replace the OEM P/S?

[NonSequitur777]

@LADave,

Welcome to our HP User Forum!

In case you determine to replace your OEM PSU (HP p/n: 460888-001), you can get these units for under $30 via eBay: https://www.ebay.com/itm/134141319724?hash=item1f3b721a2c%3Ag%3AlvkAAOSwL1lin7NE&amdata=enc%3AAQAHAA....

Kind Regards,

NonSequitur777