No output to Monitor

[schultzm]

When I turn on a Hi-Tec PC it does not always send output to the monitor.

Any Suggestions?

[Budfred]

First thought is we need a lot more info if we are going to be helpful. Specs, OS, what other problems you have, what shows on the monitor, what was going on prior to the problem starting, what you have done for troubleshooting already, how often does it fail, are there any particular circumstances that seem to be true when it fails and any other info that would help come up with ideas.

That said: have you checked connectors? Have you made sure your video card is seated properly? Have you tried a different monitor? Do you have good surge protection?

[schultzm]

Motherboard: ABIT-KT7
CPU: AMD Athlon 1GHz
RAM: 256Mb
Video: ATI Rage Fury 128 Pro
HDD: Maxtor 53073H6
DVD: Pioneer DVD-I0J
OS: W2K SP3
BIOS: Award Modular v6.00 PG

Symptoms:
1> On booting the PC there is seldom any Video output (It is possible the system does not boot at all?). When booted a second time the boot sequence is normal with video output.
2> USB modem connection to ISP seldom works - requires 3-4 attempts to connect successfully.

Diagnostics:
1> I have removed all unused PCI cards to see if there is a PSU problem but the symptoms remain.

ABIT Technical Support
Suggested this could be a faulty motherboard.

Your comments would be appreciated.

[Budfred]

When you boot and don't get any video, are you getting any signs of life at all??? Particularly, are you getting a POST beep? If you are getting nothing at all, it is probably not a video problem.

The intermittant nature of the problem suggest that the power supply or RAM could be at fault. Removing PCI cards will not be enough to test the power, it would probably be worthwhile to disconnect a drive (probably the DVD) to see if that makes a difference. Different legs of the power supply could be bad without the whole thing being bad.

To test RAM, you can download DocMem (http://www.simmtester.com/PAGE/products/doc/docinfo.asp) and use it.

Have you checked all connections? It could be as simple as a loose wire.

[schultzm]

When powered up there is brief activity on the DVD but no activity to the Video output or HDD (boot device). The POST beep is not heard i.e. it does not boot.

DocMemory shows 3 errors with the burn-in test - results attached. There are 2 banks of 128Mb but it looks like there are faults on both as removing one or other and swapping them makes no difference. These errors are not detected by the BIOS.

Disconnecting the DVD made no difference as did swapping the power leads.

Do you think the memory is the cause or the motherboard?

[Budfred]

If you are picking up errors in the RAM, that is the likely cause. Fortunately, RAM is pretty cheap these days. If you are in the USA, you can check the Sunday ads and probably find 256 Mb RAM for about $20 a stick.

If you have access to another stick of RAM, it would be worthwhile to try it just to be sure before going shopping....

[schultzm]

Is it usual that DocMemory identified a problem but BIOS did not?

[Budfred]

Yes, BIOS does a basic check mostly confirming that the memory is there. It doesn't do a thorough check to make sure the memory is ok. It is like the way it checks the hard drive, it will not pick up on serious problems. That doesn't mean that it is a good idea to trust DocMem completely which is why I suggest testing another stick of RAM if you have one available to test with. However, usually if a memory tester picks up on something and you have the symptoms that led to using the memory tester in the first place, it is likely you have a RAM problem....

[schultzm]

Tried DocMem on my Dell Dimension 4300 (which has compatible memory) and it completely froze. Had to power cycle to reboot.

Is this a known problem?

[Budfred]

No, usually DocMem runs fine. If it isn't working properly for you it could be a problem with your disk or a corrupted download or something else. You might want to try a different RAM tester to see if you get similar results. Memtest96 (http://www.memtest86.com/) isn't quite as easy to use, but it should confirm or disconfirm the results of the DocMem test....

[schultzm]

I have replaced the RAM with error free memory and I still have the same symptoms - does this mean the motherboard is defective or can you suggest any other problem areas?

[Budfred]

It could be the motherboard, but it isn't clear what it would be on the motherboard. Often if there is a problem with the motherboard, it won't work at all, intermittant failures are tougher to track down. Since you were getting errors on RAM, it is possible that the motherboard has bad RAM slots, but again that is a longshot.

Power supply could still be the problem, it would take either trying another known good PS or testing with a multimeter to rule it out completely.

Also, I don't think I suggested before to check the capacitors on the motherboard to make sure none are bulging, leaking or burst. This is another problem some boards have because of an issue with using a bad electrolyte in the capacitor.

Another option is to do a minimal boot outside the case to rule out the possibility of a short. You would place the mobo on a nonconductive surface, like a piece of cardboard, and keep the CPU, PS, one stick RAM, keyboard, video, case speaker and power switch connected. You then test to see if the problem continues. If it doesn't, it means that you either had a short or there is something wrong with one of the components that are disconnected. you can try adding back one component at a time and test each time to rule out the second option. If still no problem, you have a short with the case somehow and you need to reinstall the board very carefully to make sure that it doesn't happen again. Since the problem varies, it would probably be something that moves a litte bit, causing the short only some of the time.

[schultzm]

Problem solved - read the ABIT docs and figured that the CMOS clock speed for the AMD Athlon 1GHz was incorrectly set.

During the investigation we also identified duff memory - so it was not a totally lost cause.

Thanks

[Budfred]

When all else fails... read the documentation!!!:D

Congratulations on figuring it out.

Now that it seems to be running ok, you may want to retest the RAM. It may be that the wrong setting on the CPU was also effecting the RAM test and it may actually be okay...

[ErnieK]

Documentation!? What is that? Is that the stuff that goes into the back of the fire?:rolleyes: