Strange problem - computer freezes, monitor goes blank

[imported_mbapu]

Hello Everyone,

Sorry for the long post. Just want to describe all the symptoms.

This problem has been bugging me for two weeks now. I tried everything I can think of, still can't fix it and the problem is getting worse (more frequent freezes and sometimes windows doesn't even come up).

I have a HP Media Center PC m7277c, with 2 DVD-RW drives (One IDE, One SATA), a 500gb SATA Seagate HD, 4gb RAM, ATI Radeon X600 video card, Hauppauge TV tuner, PCI Belkin WiFi card, built-in network card, modem.

Computer works fine until the monitor goes blank all of a sudden. (PS2) Keyboard does not respond and the computer's light on the front panel stays on. I can open and close the DVD. But the fan on the back is not turning. Some times, it freezes within a few minutes after turning it on and sometimes, it goes for > 24 hrs before it freezes.

I had an older 160 IDE HD in there. Thinking that might be causing this problem, replaced it with a new SATA HD. No luck. Sometimes, I noticed its freezing while transferring files (either locally from one folder to other or from my external USB HD). I disconnected all external USB HDs. Still same problem. Connected a different monitor - no luck.

I am running Vista ultimate. Never had this problem before when I was running it on Windows XP MCE. But, it ran OK for about a month after installing Vista and then the problems started. I have all the latest drivers I can get. Have the latest BIOS (04/20/2006-LakePort-P5LP-LE-00) Rev. 3.17 Phoenix Award BIOS v6.00PG

Main Processor: Intel Pentium D 3.00GHz (200x15.0)
While turning on, after it detects the processor, sits there for a good 5 minutes before any other post comes on screen.

I have to power cycle to restart it. Once it starts again, it will ask me if I want to go into safe mode. It does not make any difference whether I am in safe more or in normal mode. Thought this behavior is because of heat. So opened up the case and made sure it has enough airflow. Tried it at different times of the day, day and night. No change.

The original power supply that came with it stopped working. Replaced it with a new 500w CoolMax about a year ago.

Any thoughts on what could be wrong with it? Whats mind boggling is it is so intermittent

Again sorry for the long message.

Thank you!

 

[Paperdoc]

I can't tell you how to fix, but have a couple suggestions to look at, mainly based on the problems with capacitors in power supplies. You have an intermittent problem, obviously, and that's frustrating.

Take a close look at the capacitors in your PSU AND on your mobo. A faulty one in either location could give you power trouble. Look for ones that are distorted - they are supposed to be cylindrical cans with flat ends. Any with bulgy sides or tops need to be replaced before they get worse.

Then there's my old stand-by trick. You could have a connection somewhere that is getting bad just because of normal oxidation. These are impossible to see. So I go through the entire system carefully and unplug, then re-connect any connector I can find, several times each. Just doing that sometimes cleans off the metal surface and gives a better connection. Be careful not to bend or force anything, to avoid breaking it. While doing this, keep an eye out for actual loose, poorly-fitting connections that might need tightening.

Last suggestion is to check airflow. Pay particular attention to grids or filters in the air path that might have built up a bunch of dust. Look closely at the heat sinks and their fins on BOTH the CPU and the GPU (on the graphics card), and brush or vacuum them off gently if they are clogged. If you have a software utility for it (maybe even built into your BIOS), check any system temperatures now and after cleaning to see it there are improvements.

 

[imported_mbapu]

Thank you so much PaperDoc, for all your suggestions. I will try them tonight.

 

[imported_mbapu]

PaperDoc, you are right on. All the capacitors looked good. Looks like there is loose connection. Don't know which one, but I disconnected/reconnected the drive connections to the motherboard. Turned it on. There is no 5 minute delay I mentioned above. Been running since last night... Hope the symptoms won't come back when I close the thing!