|Lon story short: we had a power failure, and my wife's system does not power up.|
System: Store bought, HP Pavilion 9400f, AMD Phenom X4 9750, 8GB RAM, 750GB HD.
When power switch is pressed, absolutely nothing happens, no fans try to spin, no lights appear anywhere, nothing.
HP docs on this system are not good.
I pulled the covers and looked around. I see no obvious burns or signs of damage.
Motherboard appears to be a MCP61PM-HM, HP P/N 5189-4598. I think this is an Asus based mobo. It has a pretty standard and obvious layout.
PSU part number is HP 5188-2589. It is 350W, but there is not a lot of hardware to drive in this system. And has worked unchanged for about 2-3 years.
Further diagnostics: the PSU has an LED, which does show green when external power is applied. This seems suspicious to me. So I ....
pulled the PSU, and ran standard bench tests. They are clean: 3.3 where expected, 5 where expected ,......
I should mention: this mobo does not appear to have a single 'power present' LED. Either that or I am blind.
I am looking for suggestions as to what to try next, because I am baffled at this point. I have the feeling that throwing a new PSU at this is not going to fix anything.
Would appreciate any thoughts from folks more savvy about hardware than I am.