I have a computer that the monitor is not getting a input signal. However, the monitor works on my other computer. I cannot open the cd drives. Sometimes when I turn the computer on it DOESN'T come on. I was wondering if it is the video card or the power supply or the mother board or all of the above. I need help.What should I do?
Thanks Cptplug

Hi there CTP
First (and easiest) thing to check is your PSU (power suppply)

Try disconnecting it from the mobo and reconnect again. If this makes no difference see if you can get anothe PSU from somewhere and try that.

Hello cptplug.

You could use a copy of my diagnostic charts.
Download them from here
www.erniek.eclipse.co.uk/downloads/sylvanderdiags.zip
or send me a personal message requesting them [zipped or not] and giving an e-mail address to send them to.
My copies are the first to be updated/amended and I send updates to those who get them by e-mail.

Some routes through them:
-------------------------------
DEAD PC

STARTUP
1. Is the PC dead? Yes.
2. Go to the SYSTEM chart.

SYSTEM
1. The PC appears dead.
2. Does the PSU fan run? No.
3. Are the power supply voltages correct?
If they are then the PSU fan is faulty.
If they are not, then disconnect all peripherals from the PSU.
4. Does the fan now run?
If it doesn’t, then you have a faulty POWER SUPPLY [go to that chart].
[If the fan runs, then on an AT system, re-connect the system board].
5. Does the fan run now?
a. If it doesn’t, then the AT system board is faulty.
b. If the fan runs, then re-connect one device.
6. Does the fan run?
If not, then this last device is faulty. Disconnect it.
If it runs:
7. Are all devices connected?
If they are, then re-test the system [go to STARTUP].
If not, go to 5b and repeat the steps until all non-faulty devices are connected, then re-test the system.

[b]POWER SUPPLY
This is too extensive to quote.
It involves:
Checking the mains supply.
Checking the mains lead and replacing if faulty.
Shorting the switch connections on the M/B if necessary and replacing the switch if it’s faulty.
Shorting the green & black wires on the power connector to the M/B.
Diagnoses = either:
1. Motherboard fault.
2. Faulty PSU.
3. Faulty mains supply.
4. Faulty mains lead
5. Faulty on/off switch.
--------------------------------------------------
NO POST

START UP TEST
1. Is the PC dead? No. [You have fans, lights, etc]
2. Did POST appear to run? No.
3. Were there any audible beeps? No. [a single beep indicates successful completion of POST]
4. The Power-On Self-Test failed to complete. [NO POST]

NO POST
1. Are the PSU voltages correct? Check them if you can. If they are not you may have a faulty PSU. Assuming they ARE ok then:
2. Disconnect all peripherals and system adaptor cards except the keyboard and video card/monitor.
3. Does the POST now run? If it doesn’t then your system board [or something on it (video card, CPU, memory)] is faulty. If it does run then:
4. Re-connect the floppy disk drive and run advanced diagnostic software from a floppy disk.
[Get “TuffTest-Lite” from http://www.tufftest.com/free.htm or better if you can. This is simple and basic.]
5. Does the system board pass? If not then it is faulty. If it does pass then:
6. Switch off and re-connect ONE peripheral/adaptor card.
7. Does POST now run? If it doesn’t this last device connected is faulty and should be disconnected. If it does run the device should be tested using the diagnostics and if it fails is faulty and should be disconnected. If it passes it's ok and should be included.
8. Repeat from step 6 until all devices are tested, all faulty are excluded and all working are included, then re-test the system.

If you want to simplify the test for a first attempt at a fix you could assume the PSU is ok and leave out the tests with diagnostic software.