Computer Turns ON—No Beeps—Black Screen

[earguy]

A client dropped a desk top by today that turns on, but the monitor is black and there are no beeps when the unit is first turned on. I know the monitor is good as the OS loaded the first time I turned it on, but when I tried to perform a CHKDSK /f /r and had to reboot for it to begin—nothing booted up and the screen was black again.

The client's son built the machine so it isn't from any particular manufacturer. I tried locating the name and serial number of the motherboard, but to no avail (actually what I saw was AN52-ECK003780 but nothing comes up in Google). My question is: What would cause this to happen? A bad CMOS battery maybe? I even tried installing a new graphics card, but no change. I removed both memory modules and tested each one in each of two slots, but nothing changed.

I'm sure for some of you more experienced techies, this is a walk in the park. For me, a newbie (3 yrs), it's frustrating. Any suggestion(s) would be greatly appreciated. Thank you.

 

[FremontPC]

Try removing the power cord and holding the power button down for 30 sec. Hook it back up and see if it boots.

Maybe an Abit mobo? Google AN52 and you'll get some hits. If you ever get into BIOS you might want to see if it's set to overclock.

 

[gikstar]

Also, try hooking up a known good power supply and see what happens. Look for bad capacitors on the motherboard too. Onboard video? If not, check for bad capacitors there also and swapping out the video card.
Remove the ram and hit the power button... Usually if you hear no beeps then you have a bad motherboard, but verify the power supply first before deciding that the motherboard is bad because you hear no beeps.

 

[FremontPC]

Yeah, 2008 vintage, if I'm not mistaken. Definitely want to screen for bad caps.

 

[citizensmith]

Also, try hooking up a known good power supply and see what happens.

^^^that and check the power button actualy works. You could maually power up it with link to Green + Black ? http://aphnetworks.com/lounge/turn_on_psu_without_motherboard_the_paperclip_trick Do'nt drop paper clip onto mobo
Is the PWR switch connected to to the right pins?
CLR CMOS jumper still set so no start up?
If its a total DIY job it might be Destroyed it Yourself

 

[fabs]

That may be a power supply failure. We had some computers here that were behaving the same way after power problems. Things got back to normal after replacing power supplies.

 

[B Trevathan]

If the monitor is black form the start, what is the monitor doing does it display no signal, does the monitor power light change color or does the light blink?

If you are seeing the BIOS load and then the monitor goes black then try booting from a live CD like a Linux disc or an AV rescue disc.

What are the lights on the computer doing, is the hard drive light or the DVD light or the power button light on or blinking, is there any lights on the back of the computer like on the power supply or NIC, what are they doing are they on or blinking, are any if the lights changing color going from green to amber? Is there a light on the motherboard?

Are all the fans spinning? Can you hear and feel the hard drive spinning?

Are you using the customers monitor, monitor cables, keyboard, mouse, power cord ? Anything else plugged in?

What software did you use to test the RAM?

Why where you running CHKDSK?

 

[earguy]

Try removing the power cord and holding the power button down for 30 sec. Hook it back up and see if it boots.

Maybe an Abit mobo? Google AN52 and you'll get some hits. If you ever get into BIOS you might want to see if it's set to overclock.

Thanks. I have removed power cord and held the power button several times. Nothing happens.

 

[earguy]

Try removing the power cord and holding the power button down for 30 sec. Hook it back up and see if it boots.

Maybe an Abit mobo? Google AN52 and you'll get some hits. If you ever get into BIOS you might want to see if it's set to overclock.

You're correct. it is an AN52 motherboard. Thanks.

 

[earguy]

Yeah, 2008 vintage, if I'm not mistaken. Definitely want to screen for bad caps.

If by caps your are referring to capacitors, they all look fine.

 

[earguy]

Also, try hooking up a known good power supply and see what happens. Look for bad capacitors on the motherboard too. Onboard video? If not, check for bad capacitors there also and swapping out the video card.
Remove the ram and hit the power button... Usually if you hear no beeps then you have a bad motherboard, but verify the power supply first before deciding that the motherboard is bad because you hear no beeps.

I checked power supply and it is good. I removed ram and inserted each module in each of the slots and nothing changed. Capacitors look fine. I swapped out the video card and still no change.

 

[gadgetfixup]

Break it down. Unplug everything from the motherboard but the power. No cards, no HD, no Optical drive, no wires but power supply wires. Use a small straight blade screw driver and short the power pins to turn it on - safer than a paper clip and you probably won't drop it

We've see all sorts of things keep a board from posting. Stuck reset buttons, bad Optical drives, bad Modem cards, all sort of things. So we take a couple stabs at it and then break it down to bare minimum. If you still don't get any video, remove that HSF and check if the CPU is warm. Power it up and see if it heats up. If it's stone cold then it's board time.

 

[Larry Sabo]

I checked power supply and it is good.

How? Only by swapping in a known-good PSU can you be sure. Those testers often lie; well, they say the voltages are fine but they fail under load.

 

[Martyn]

How? Only by swapping in a known-good PSU can you be sure. Those testers often lie; well, they say the voltages are fine but they fail under load.

Agreed, have had many like that. Swap for known good without a doubt

 

[HFultzjr]

Can you boot to an alternative operating system, such as Parted Magic?
I have seen a bad hard drive cause a live cd not to boot.
Bad hard drives can cause many issues and be the first thing I would check.
If so, run some diagnostics from there.
Sounds like you need to run a FULL diagnostics, in place of just hunting and pecking until you hit "the magic" thing that will make it work.
Without a FULL diagnostics, this may just be a temporary fix and may come back.
There are several threads on here about how to do a FULL diagnostics.
Parted Magic is a good place to start.
By the way, did you clone the hard drive? You may want to do that FIRST.
Rule #1......Save the data first.

 

[DanF]

I would try to power it on outside the case, with bare minimum hardware. It's also easier to try a new motherboard like this.

You should definitely try a new PSU.

 

[gadgetfixup]

How? Only by swapping in a known-good PSU can you be sure. Those testers often lie; well, they say the voltages are fine but they fail under load.

We confiscated all our techs testers for that very reason. They measure voltage but not amperage. You can have voltage without amperage without a load. As soon as a load is put on the PSU, the voltage disappears. The only way we test now, like other veterans here, is with a known good PSU.

 

[earguy]

^^^that and check the power button actualy works. You could maually power up it with link to Green + Black ?

A client dropped a desk top by today that turns on, but the monitor is black and there are no beeps when the unit is first turned on. I know the monitor is good as the OS loaded the first time I turned it on, but when I tried to perform a CHKDSK /f /r and had to reboot for it to begin—nothing booted up and the screen was black again.

The client's son built the machine so it isn't from any particular manufacturer. I tried locating the name and serial number of the motherboard, but to no avail (actually what I saw was AN52-ECK003780 but nothing comes up in Google). My question is: What would cause this to happen? A bad CMOS battery maybe? I even tried installing a new graphics card, but no change. I removed both memory modules and tested each one in each of two slots, but nothing changed.

I'm sure for some of you more experienced techies, this is a walk in the park. For me, a newbie (3 yrs), it's frustrating. Any suggestion(s) would be greatly appreciated. Thank you.

I didn't see the on/Off switch on the power supply. I turned it off, pressed the power button for several seconds, turned the switch to ON position, and the machine booted.

On the Phoenix BIOS window it gives me the following messages:

"Display switch is set incorrectly"
"CMOS checksum error - Defaults loaded"
"Override enabled - Defaults loaded"
"Warning! CPU has been changed"
"Please re-enter CPU settings in the CMOS setup and remember to save before you quit"

I entered BIOS setup and noticed that the date and time are off. However, I was unable to make any changes. I will Google the Phoenix BIOS and follow their instructions.

Windows is loading at the moment. I have to leave for the day, but will return in about 8 hours. Again, thanks for the help eveyone. I'm sure with your advice I will get this thing up and running well in no time soon.



Do'nt drop paper clip onto mobo
Is the PWR switch connected to to the right pins?
CLR CMOS jumper still set so no start up?
If its a total DIY job it might be Destroyed it Yourself

The CMOS jumper has no jumper stunt.

 

[earguy]

I would try to power it on outside the case, with bare minimum hardware. It's also easier to try a new motherboard like this.

You should definitely try a new PSU.

Good advice. Thanks.

 

[earguy]

We confiscated all our techs testers for that very reason. They measure voltage but not amperage. You can have voltage without amperage without a load. As soon as a load is put on the PSU, the voltage disappears. The only way we test now, like other veterans here, is with a known good PSU.

Good advice. Will do that later on today. Thanks.