Home made, worked fine until I decided to disable front audio and enable rear ports; opened case, changed a couple of jumpers on MB (MSI Neo 2 PFISR), vacuumed dust from processor fan/heat sink, closed case, then nothing.
Fans spin, as do FD and HD but no video, no boot, beeps or anything. Have re-seated all MB connectors, except main power, wiped CMOS; won't even boot from start-up floppy.
I'm stumped, hoping for useful suggestions.Are all cables back like they were at this point? If not, do so, and see if it works.foam4me...Hard to tell from your description ...but are you certain you didnt dislodge a card or something else when you were inside the case ? Have you reset your CMOS defaults ?  Are you certain the jumpers you changed inside are correct ?

dl65  I re-seated IDE connectors on mobo and rear of drives, video card in AGP slot; there are no other cards to move/re-seat.
No way to RENEW CMOS as no POST, video, or any other signs of life except the spinning fans on processor and Northbridge, lights on optical drives when power on, and signs of life from FDD. Again no beeps, no video.
The jumpers were done as directed from manual that came with mobo, have not re-connected original cable.
I thought to check PIN voltages on power supply but have not tried to reseat power connector.
The most frustrating thing is that the MACHINE was built in January and has worked flawlessly until this debacle.Any chance the processor got damages either by ESD, improper seating? Is the processor fan on correctly? If no post, most likely that or power supply. Can you check with a known good PSU?

Are the jumpers back like you had them (when it ran correctly) or per manual (which may have a typo)?I don't think ESD is the issue (I wore a grounding strap when working on the mobo)although I think it is hard to check. When vacuuming the dust I tried to be careful with the vacuum tool, and it was running on 110 ac, but it may be possible that something was damaged; I hope not.

I'll try refitting the original audio cable to the top panel.maybe you need to plug in the video card...... Quote

maybe you need to plug in the video card......

I don't think ESD is the issue (I wore a grounding strap when working on the mobo)although I think it is hard to check. When vacuuming the dust I tried to be careful with the vacuum tool, and it was running on 110 ac, but it may be possible that something was damaged; I hope not.

I'll try refitting the original audio cable to the top
panel.