Monitor screen is black—computer turns on by itself.

[earguy]

I am working on a desktop eMachine ET1831 w?Windows 7 Home Premium SP1.

I serviced this computer last week and removed a fairly large amount of malware. All seemed well.

The owner called me today to say that his computer hasn't been working for a few days now. When I power on the computer there is nothing, no beeps and nothing on the monitor. I hold down on the power button to shut it off, then I unplug the power cord, hold in on the power button for a few seconds and then, when I reinsert the power cord, the computer powers on by itself without out pushing the start button. I installed a new PSU and the computer starts normally, but still nothing shows up on the monitor.

I removed the RAM chips and inserted them one at a time, but nothing. However, the computer started to turn on again by merely plugging the power cord in. After a couple of shut downs, the unit starting turning on as normal, using the start button.

I have tried three other monitors that I know work as I use them daily but the screen is still black.

Ideas?

Thanks

 

[Kitten Kong]

Short on the actual power switch?. Have you tried removing the power switch from the motherboard, and see if it still does it?.

If it did, I would lean towards possible mobo fault.

 

[BlackLabTechs]

I'd try removing the "eMachines" label and slap a Dell or Lenovo label on there. Should boot right up!

 

[earguy]

Short on the actual power switch?. Have you tried removing the power switch from the motherboard, and see if it still does it?.

If it did, I would lean towards possible mobo fault.

I haven't removed the switch yet. That's a good Idea and I will do it. Thanks. Any ideas on the black screen?

 

[earguy]

Seeings how I think the problem with the blank screen is the on-board graphics port, if I install a graphics card, will the computer default to the card or do I have to configure it in BIOS?

I removed the switch and the computer did not turn on when plugging the cord into the back of it. However, it is intermittent.

 

[nlinecomputers]

Sounds like a dead motherboard to me. Why waste time on it? It has no video and power issues even after replacement of the PSU. I assume that you have stripped it down to the bear essentials? No drives. Only memory, video and a KB. If you can't get any further then that pronounce it dead and move on.

 

[earguy]

Sounds like a dead motherboard to me. Why waste time on it? It has no video and power issues even after replacement of the PSU. I assume that you have stripped it down to the bear essentials? No drives. Only memory, video and a KB. If you can't get any further then that pronounce it dead and move on.

I have stripped it down as you've suggested. I will take your advice and pronounce it dead. Thank you.

 

[MichaelBits]

Just to note....

Some desktops have a bios setting for power on after power loss. If set, it will kick on anytime power is applied to the machine, meaning plugging in the power cord.

 

[earguy]

When I delivered the unit to my customer last week, all was well. The monitor flashed yesterday for a moment before going and remaining black. I hadn't thought about this until just now but, would removing the CMOS battery for a BIOS reset possibly help this situation? Ninecomputers suggests a dead mobo and I think he is correct. I really am not wanting to tell this poor guy he needs another computer.