Black screen on Dell Dimension 5100

My secondary computer, a Dell Dimension 5100, 2.8ghz, 160 G HD, 4G ram, 305 watt power supply, mfg 2005, win 7 OS, has a black screen at startup. Monitor good, has monitor logo at initial power up when power strip turned on, not computer, then goes to standby mode, and then black. I tried a second monitor also, still dark. I replaced video card, and tried onboard video, still no good. Fans run, hard drive spinning, power light lit on mother board, CD and DVD drives spin up. I have 4 sicks of 1G ram, which I removed one at a time, still no joy. I removed battery to reset BIOS, still nothing. I tried the F8 key, with no effect. The power light on the front of the computer stays amber. I tried control-alt-delete also.

Where should I go from here. Could it be a virus? How can I trouble shoot this?

 

You said the power button remains amber, I had a friends Dell OptiPlex 780 do that and it ended up the motherboard went bad but I was able to pick up another board on EBay for $25 and replace it. It could be the power supply but in my case it was the board. Check for bulging or leaking capacitors on the board. In my opinion any PC older than 2006 will probably have leaking capacitors. I had to change my 2009 Dell SC430 board out because of Bad Caps.

 

No beeps on power up. Only the main power button light remains on, and it stays amber. Looks like we are getting close to a solution. I see a board on ebay for $60. It's a 3.0 ghz. I hope it will work. It looks the same. Any more info would be appreciated.

https://www.ebay.com/itm/Dell-Dimen...:94EAAOSwkvtcJQNj:sc:USPSPriority!19465!US!-1

 

You have to look at your mother board and make sure you have the same number, Dell may have used a couple of different boards in each model . Is yours a J8885 REV A03? Just because the Ebayer says its a Dimension 5100 board doesn't mean it is so. Also are you able to do a board change out? I read where yours only can use the Prescott CPU's??. I upgraded my Dell SC430 from a Celeron to a Pentium Dual Core 945 @ 3.4 Ghz for $25 on EBay, they can't run the Core2 Duos.

 

I just looked, the listing on my board is DS/N CH0J8885-69861-56A-11FO C/0 CN REV A03. As far as ability to change out a board, what do I need to know? Other than the physical swap, is there software setup requirements? Also, will going from 2.8ghz to 3.0ghz, cause any issues? This is all new to me. I have rebuilt tv sets, but as far as computers go, all I have done is add ram memory boards, and replace a bad CD drive unit.

 

OK then that is your board, just the physical swap and fresh heat sink compound on the CPU. I never know what kind of experience a poster has but if you have done TV's then your good. You may find Info on YouTube also. I used to work on CB radios back in the 80's.

 

I ordered the mother board. It should be here the beginning of next week. I may need your advice if I run into trouble swapping it out, and getting it to power up. I believe I have some leftover heat sink paste, used for the TV horizontal hold power transistor.

 

I am a sentimental kind of guy. Kind of a learning experience also, swapping out a motherboard and getting it to work.

 

The new motherboard came today. That was the problem. Computer is up and running with the new board. Actually it was a board from a parted out computer. I have a bunch of display defaults to modify, but that's no big deal. There was no grease left on the heatsink for the CPU on the old board. I suspect that it was the component that went bad. There was one memory card that came with the new board, that was of a higher speed. 4200 vs 3200, of the existing 4 memory boards. I am hoping it won't make that much difference.