Computer help forum: PC won't boot, even with clone?

Not even a flicker on the display. No logo, no bios indication, nothing at all. Nothing on the keyboard, either.
Sorry about the details: HP m9340f, desktop. It originally had Vista long ago, but I installed Win 7 (upgrade) years ago. The monitor is working properly. Shouldn't the hard drive indicator be lit all the time? It's not. Not at all.

As for HD indicator, that's only activate when the HD is being accessed. Even during power-ON it may flash for a moment but continued flashing indicates its being accessed.

Since, nothing displays, that hard to fix. It suggest either the video side is gone(reseat card or cables), mtrbd. bad or monitor or PSU. Now, you say the monitor is good. Unplug it and it should display a "no signal post" or similar provided its a newer monitor.

Since, your HD flashes for awhile it starts to boot, but stops or it isn't getting the proper signals or passing them on. Since, you've swapped the HD out and it still continues to NOT display, then that leaves the mtrbd. or video. Since Vista was original to the PC, it suggest it has some yrs. on it. What maybe happening, the PSU has failed due to wear&tear. Having fans and drives running only suggest at least 12V is present, probable 3.3V or 5V is goner or off. If you have a spare PSU of similar type, swap it out. You can jerry-rig it to have it hanging and supplying the connections just to see if it boots differently, maybe all the way. If OK, then replace PSU with a good one or similar wattage or better. You can try a "video card" if yours is mtrbd. video port or replace card with a working one. However, for now a bad PSU seems likely. Just be sure you get a physically similar one plus right(or better) wattage. I would think a "generic" PSU will do fine.

tada -----Willy

It took me a while to try some of these suggestions. Thanks for being patient.

I had a video card on hand. First, I tried re-seating the current card. No change.
I put in the older card and, again, no change.

The power supply unit...that took me a while. The existing unit was an upgrade, and seemingly worked. I undid it, though, and put the old one back (as you suggested, letting it hang outside the case.

This also did not make any difference.

The monitor is definitely working properly, as I checked it with another machine.

At no time does the keyboard light up.

So, it sounds like the mb is toast? Oh, well. Maybe a good time to upgrade the machine.

Unplug the AC cord for 10min. and then reconnect and check results, powering it ON. If it remains the same, then if you want, tear down the PC. Disconnect all drives and remove video card. Find the CMOS clearing pins, use that to reset the bios. Now try to power-ON, does it show any display? If no, then inspect the mtrbd. closely for any "bad caps" damage. Google for examples. If nothing seems to work, then you can conclude the mtrbd. is hosed. if you want, buy another one via eBay or Craigslist at some cost. Swap it out with old one and it should boot as if nothing happened. Of course, provided there no 2ndary cause that may have broken the PC ion the 1st place, why the mtrbd. got hosed.

As I posted before if you make a bootable disc using the Ubuntu "live version" and simply place in CD/DVD. Boot it up even if no display but the CD drive seems to flash like it's booting, you may have a bad video card and/or on-board port. If no card and you swap to on-board video port and see if anything displays. Basically, this is all a last resort thing, but if it seems to want flash yet no display, then the video side has hung the PC for whatever reason. I don't think I can offer more than this for now.

I have tore down the PC and place on cardboard on table. Use only basic system, no drives, ONLY ram, kybd., mouse and mtrbd., test that way with PSU attached. The power-ON/OFF not the connection and momentary touch with small screwdriver(metal) will act as a switch, same for ON/OFF.

good luck -----Willy

I should add, disconnect all USB devices except for possible kybd and mouse for now, Retest w/o any and see if that makes a difference. ------Willy

Willy, thanks, but the machine is old enough that to go through this renovation process would be, say, less than desirable. A new computer, with bigger RAM, USB 3.0, processor, etc. is what I'll do. I'll stimulate the economy a bit by sinking some money into a new machine. Thanks again.