Pc Problem

[PETERTHEEATER]

HP a18389l Presario Desktop, out of warranty. Loaded with XP Home Edition

Monitor connfirmed good.

Was working OK, on shutdown, Windows informed that uodates were being installed and PC would be shut down automatically.

I left it for 10 minutes and when I returned the monitor was blank so I switched off power to the mains as usual.

Next day, switched on but PC would not boot - blank screen i.e no signal to monitor.

Visible symtoms are:

Power is ON and fans are running.

HDD Indicator lamp is ORANGE and never changes.

Two installed CD-ROM drives, the green indicator lamps flash between one and the other continously as if the BIOS is trying to boot from one or the other (no discs loaded) and cannot see the HDD.

Tried alternative HDD - same problem.

Tried booting with HDD disconnected - same problem

Checked all connections to motherboard etc, etc.

Assume that during the previous day's Windows auto update that it had not finished and that the monitor was blank because it was in sleep mode so may have corrupetd the BIOS?

Tried re-setting CMOS to defaults by removing battery and replaceing - same problem.

Tried installing DOS update (.iso file whatever that means) from CD-ROM disc during start-up but disc is not read by either drive.

Tried booting from XP CD but disc not seen. Both CD-ROM drives will not read any disc during start.

The graphics card is almost new and the whole tower has the side removed and has a desk fan blowing on it all the time when operating so overheating should not be a factor.

Tried booting with HDD and both drives disconnected same fault but, I'm told, there should be system 'beeps' in this case but just the same fault, no system noises.

Tried all combinations of connecetd/disconected HDD and CD-ROM drives but same fault regardless of configuration.

Unfortunately, my new PC is under warranty so I don't want to swap parts to assist troubleshooting.

I have aired this in another Internet forum but no positive feedback so lets see what Thai Visa members suggest.

Over to you for comment.

[Supernova]

Assume that during the previous day's Windows auto update that it had not finished and that the monitor was blank because it was in sleep mode so may have corrupetd the BIOS?

No.

Does the computer POST? If so, do you hear any beep or is there constant beeping? If the computer doesn't POST, the first thing I do (apart from resetting the BIOS to factory defaults) is disconnect ALL hardware devices leaving only the CPU. Then I power on the computer; if it still doesn't POST (no beeps are heard), I remove and reseat the CPU the try again. Also check the motherboard for any physical defects, most notably, bulging capacitors. Also try an alternate power supply (PSU) while your at it.

Edited September 16, 2009 by Supernova

[Saraquin]

Hi

I understand wanting to avoid part swapping but to be sure of a solution its going to have to happen

a few things i would suggest you can try are:

remove all drive connections to mainboard

then take out the ram sticks and see if you get any response from the bios either beeps or preferably some screen action

Im assuming you never got any love from the screen with your efforts? did you try re-seating the video card or removing it and using the onboard vga if you have one?

and lastly drop all the un-needed power connectors incase its a dodgy PSU and run it on bare minimum.

good luck.

[PETERTHEEATER]

OK supernova and saraquin,

Since it was working OK up until the last shutdown, I assumed that I may have inadvertently corrupted it by switching off too soon.

The PC does not POST, there are no 'beeps' at all.

The fans run, the start button indicates power ON, the HDD drive indicator lamp is steady orange all the time; does not change to green at all.

I have removed and replaced the motherboard battery to restore the BIOS to defaults; it's a new battery too.

I have (again) disconnected the HDD (both power and signal connections) and both CD-ROM drives (power and signal) - same fault

I have removed and re-seated the graphics card - same fault

I have tried booting with the RAM chips in and out - same fault.

I have disconnected the monitor - same fault.

I think an older PC (Compaq) has a compatible PSU, if so I shall try slaving it in but not today.

[Supernova]

OK supernova and saraquin,

Since it was working OK up until the last shutdown, I assumed that I may have inadvertently corrupted it by switching off too soon.

I don't see how that's possible. A 'short' somewhere is more like it.

The PC does not POST, there are no 'beeps' at all.

The fans run, the start button indicates power ON, the HDD drive indicator lamp is steady orange all the time; does not change to green at all.

I have removed and replaced the motherboard battery to restore the BIOS to defaults; it's a new battery too.

Replacing the CMOS battery won't help. Most PCs will run without a battery. The purpose of the CMOS battery is to remember the date and time.

I have removed and re-seated the graphics card - same fault

I have tried booting with the RAM chips in and out - same fault.

I have disconnected the monitor - same fault.

Powering up without a graphics card or RAM will generate a series of beeps under normal circumstances. More information about BIOS beep codes HERE. The fact that it's not generating any beeps (even in the absence of these components) indicates there may be a problem with (1) motherboard; (2) power supply unit; (3) CPU. Processors don't die very often so I'd rule that out for now; leaving only the motherboard or PSU as being the culprit.

In most cases, it comes down to being a faulty PSU or motherboard. If the PC still doesn't boot after replacing the PSU, take it down to a PC technician and have them take a look at it.

Edited September 17, 2009 by Supernova

[PETERTHEEATER]

Thanks for the assistance posters, all constructive comments.

I shall try another PSU if the cooection is compatible and see if that helps.

[Saraquin]

Powering up without a graphics card or RAM will generate a series of beeps under normal circumstances. More information about BIOS beep codes HERE. The fact that it's not generating any beeps (even in the absence of these components) indicates there may be a problem with (1) motherboard; (2) power supply unit; (3) CPU. Processors don't die very often so I'd rule that out for now; leaving only the motherboard or PSU as being the culprit.

In most cases, it comes down to being a faulty PSU or motherboard. If the PC still doesn't boot after replacing the PSU, take it down to a PC technician and have them take a look at it.

I agree, PSU or mobo. ahh the joys of Thai power.

Good luck.

[vrad03]

Hi Peter...

My first diagnosis of your problem in reference with the visible symptoms could be:

1. BIOS firmware was corrupt. (System hardware will run smoothly i.e. cpu fans, psu fans and hdd motors but no video signal)

-If you can remember the bios manufacturer for example phoenix, you may try to hold down this key's WinKey+B, WinKey+F and Winkey+ESC. (You may google

tips and procedures on how to restore phoenix BIOS.

2. No Beeps and no POST werecommon symptoms of a busted CPU and mother board chipset. (assuming all pc parts we're removed, PSU, Motherboard and CPU)

[liquidroof]

Try to consult some computer expert may be could better help you.

[bubblegum]

Take out the CPU and replace it after cleaning ?

[Seismic]

I had a similar problem several years ago, it was the CPU that had died (not fried....just died).

it does happen. If it is under warranty then I would suggest you take it back and use the warranty repair, if you are really serious about fixing it, I would carefully inspect the MoBo, particularly around the voltage capacitors, which are normally seated around the CPU, if any are bulging, then its the MoBo, but I would bet you have a bad CPU.

regards

Freddie

[bankruatsteve]

Sounds to me like you tried too many things - maybe too late now. Use the BIOS startup in DOS. Do a CHKDSK. It's likely that you turned off before it was done thrashing around. It happened to me once.

[Phuquephace]

Buy a new PSU