Computer Stops Responding

Computer Data The computer is a desktop and was built by VELOCITY MICRO in February of 2005 It has an Intel P4 Processor 530 with HT, 3.0 Ghz 1MB Cache It has 2GB of DDR 400 ram by Kingston It is running Windows XP It has a USB wireless network adapter, USB external hard drive, USB wireless mouse, and USB printer and scanner. The computer had memory problems very recently and WhattheTech? helped me with that. At that time it would stop with errors, and the errors were never the same. Memtest 386 showed bad memory and I replaced the modules but still showed errors. The fix was to buy more memory; your technicians were right in telling me to change the memory again. The problem now is that the computer stops responding. There is no warning and no error message. Now, the computer runs MEMTEST 386 with no problem. But it will stop responding and the only solution is to reboot it. On initial boot up it frequently stops responding and it may take two or three tries to get it started. Sometimes it starts with “start Windows Normally” and other times with “last known good configuration”. Usually, even though the wireless internet adapter is plugged into the USB port, when the computer does start there is no internet connection and no wireless internet connection shown in the list of network connections. If I remove and reinstall the adapter it is recognized and the wireless internet starts to work. If I shut the computer down in that configuration (internet up and working) it’s a good bet that the computer will not start up again on the first try the next time, and when it does finally start up the internet won’t be working. It is like it doesn’t remember the configuration or it tries to start the wireless adapter but it can’t so the boot up fails. I tried to fix the problem by updating the drivers for the wireless internet adapter but the problem persists. Also, the problem of not responding occurs a minute or two after connecting the network adapter, or turning on the external hard drive or printer. What I am saying is that it looks like the problem is related to the USB ports. However I have discovered another way to get the computer to stop responding, I have Photoshop and have used the HDR (high density resolution) feature to combine photos on this computer, no problem. Nowadays if I try to merge photos with the HDR feature the computer will stop responding in the middle of the calculations. I successfully created an HDR photo on May 9 and I am thinking of doing a restore to a point prior to that date but in an attempt to fix this problem. However, I have already gone through and got rid of all malware and viruses etc with WhattheTech?’s help. They told me a restore would undo all of that; although getting the computer to work again and then cleaning the malware again seems to be a good option to me. The computer took three tries at booting to get it started this time and has been running for about an hour now with no problems but I’m sure when I connect the wireless adapter to post this the computer will stop within minutes. Any suggestions would be greatly appreciated.

You need to inspect the insides of your computer again. Make sure all fans and heatsinks are clear of debris and that they are all spinning. Be sure to identify the fan on your video card if you have one and make sure it is working.

If I understand you correctly you say that memtest locks up after a while? If so, this is a hardware problem, period. No amount of system restore, driver updates, virus removals, or other software work will fix the problem.

Inspect the motherboard for leaking capacitors. This is common on machines around the age of yours.

While running the memory test, lightly tap on the memory modules, motherboard, and expansion cards with the plastic end of a screw driver. See if it generates errors or causes lock ups. If so, buy yourself some contact cleaner at the local hardware store and spray it in the memory slots and on the memory connections or expansion card slots and connections. While it is still very wet, plug the memory modules or expansion cards in, unplug them and repeat a few times to help clean the connections and get a solid connection. Test again with memtest until you can successfully tap on the components without problems.

Lastly, if all of these things are eliminated then finally you may have a bad power supply. This could explain why plugging USB devices in causes a freeze. The extra draw of power could be causing a voltage drop. But, I would have to say this is probably the least likely of all the things I just mentioned as being your problem.

Barring all these things, its probably motherboard failure and you should just start considering upgrading or replacing the entire system.

Appleoddity, The computer now runs the MEMTEST with no problem. The system has had overheating problems in the past and is now setting off the ASUS PROBE temp alarm now and again (with the hot weather) when the processor is in use a lot. I have been meaning to clean the fans again and will do that, check the connections, check for leaking caps, etc. and let you know. I have had the processor and chipset chip heat sinks off to put new heat sink compound under them. The power supply failed two or three years ago and I replaced it with one that exceeds the specs, I think. I am curious about your comments on the video card. Its fan has one broken blade and the video occasionally is jittery. Could the video card cause the computer to lock up? Dan

Yes. It can be the cause of your lock ups. Especially when it is doing it during anything video intensive.

Hey BiggDan, Have you had Task Manager running during any of the lock-ups? It might be worth looking into a possible software / driver problem before replacing any parts. If you are able to get Task Manager running when the machine becomes unresponsive, look out for any applications which utilise 100% of the CPU or more than 100MB of Memory. Your Network Driver, for example, could be corrupt. Even a simple broken printer driver can make a system unresponsive. If that comes up with nothing, then Appleoddity is right and you need to be looking at backing-up your documents and replacing any faulty parts. Hope that helps, Nahumi

I know I can lock it up running the HDR function of Photoshop. I was able to run this function on 9 May. (the creation date of the last HDR photo I made). Should I restore to a date prior to 9 May? If that undoes the malware fixes, could I undo the restore if it doesn't fix the problem and get back to the no malware condition? Unless task manager is visible when the computer locks up I can't see it later. The free AVG anti virus program seems to be the main user of CPU resources.

If you had a significant malware infection it will be unlikely system restore will work anyways. The restore points will be corrupt because infected files will have been deleted out of there. System restore is not the way to go here. I am still waiting for you to provide details you said you would provide earlier about fans/heatsinks, leaking capacitors, and bad connections. You might be wasting your time doing anything else if you don't check your hardware out first. The fact you have heat warnings from your computer reinforces the idea that you may have bad capacitors on the motherboard, because your system is running warmer than normal in general.

OK, I opened the machine and found the Video fan clogged with dust. The heat sink on the processor full of dust and the intake full of dust. Cleaned all. Just moving the machine to open it caused the power cable to the hard drive to fall off, must have been hanging by a thread. Hoped that would fix the problem. It seems to have gotten better a bit but it still locks up occasionally. Checked for leaking caps. None are leaking but one is bulging. Should I think about replacing it? Had the task manager running when system locked up as NAHUMI suggested. There were no programs using excessive resources when the lock up happened. I have run chkdsk on the C drive. It corrected some problems, still locks up. Is there any log that the computer keeps that may tell what is locking up the computer, is there any option I can select to log errors? Dan

A freeze - where the mouse and keyboard completely stop responding is not going to produce a log. This is almost always a hardware fault. So, its tough to narrow down. That's why we check fans, connections, memory, hard drive, capacitors, etc. Sounds like you did pretty good getting that stuff cleaned out. However, I need to know memtest runs without errors when you lightly tap on your memory modules. Memory tests could run all night long without problems and then as soon as the computer is bumped or vibrated it crashes. The heating up and cooling down of the metal causes bad connections. At the very least you should reseat the RAM for good measure, but tapping on it during a memory test is the only sure way to tell if you have any bad connections that could be a potential problem. Please tell us exactly what brand and model of memory you put in your machine. Is it all the same? Its possible you used a higher end memory with special timings or voltages, this could be a problem. Secondly, you need to make sure that hard drive connection really is secure. Your best option is to plug a completely different plug into the hard drive. For loose molex adapters (the four pin connectors used on IDE hard drives) I will take a small screw driver (ofcourse, the power is off) and bend the round metal connections on the plug in a little bit to tighten them up. Be careful not to completely collapse the metal. The leaking capacitor could be ALL your trouble. It is hard to tell with these. Personally, I would never suggest performing any other repairs without first eliminating the obvious issues. You have done most of that, but this capacitor concerns me. I have seen computers with a dozen leaking capacitors seem to work fine, and I have seen computers with one or two bulging capacitors have all kinds of problems. You can't be sure this isn't the problem without changing it. Unfortunately, thats quite a bit of work that will need to be performed by someone with good soldering skills. I don't know your background, but I would not suggest that you take the changing of motherboard capacitors lightly. And, if you find one bulging, then every capacitor on the board that is the same kind needs to be changed because they will all start going bad. I used to make the mistake of only changing the bad ones just to have the same computer come back to me 6 months later with all the other ones leaking. For you, unless you can handle the soldering of the capacitors, I would not worry about the cap right now and just make sure those other things I mentioned are checked. But, if this doesn't fix your problem then I would have to say that my next step would be changing the caps. This type of freeze could be attributed to a bad driver or something but it is highly unusual for a bad driver to cause a physical freeze of the system. Someone might suggest running your computer in safe mode for a while to see if it locks up. If it doesn't lock up this would seem to tell you that it is a driver issue, but this really doesn't tell us anything because the hardware the bad capacitor or other bad component is effecting might not be in use in safe mode. The one thing that stands out to me is the lock ups occuring during the use of USB ports. If different devices cause the machine to lock up when they are plugged into the USB ports then this is more evidence of a hardware problem. If you think about it, plugging in a USB port vibrates the motherboard and puts a larger load on voltage regulators and the power supply. My instinct is to keep following the possibility of bad hardware, loose connections, or heat problems.

I reseated the memory modules and reseated all the connections. I also took your advice and changed the connector on the Hard Drive. It is a SATA HD and the power supply connector that was on there had the pins flattened down inside the connector. The spare connector had pins that stick up nicely. After all the reseating and with the cover off (and much cooler temperatures here at the moment) the computer is running fine. More or less…… I had uninstalled Photoshop CS3 and decided to test the computer with the HDR feature that had been locking up the computer so I reinstalled it and tried to merge photos into HDR. The computer locked up. I then ran MEMTEST 86+ and tapped on the memory modules as you suggested. While tapping up and down on both modules I was unable to produce any faults. The program runs with no problems. When I first had problems with the memory I bought some on line that didn't work. The memory in the machine now was bought at a shop we have over here called "PC BOX". You take your machine in and set it up in a stall (or box) and their experts give you the memory you need based on your MB. If it works, you buy it. If it doesn't work, no charge. So, I only know it is kingston and 400mhz DDR. Just as the MB calls for and it worked no problem from the time I installed it to now according to MEMTEST 86+. I have a high degree of certainty that the memory is compatible with the MB. I was thinking it is a heat related problem and had planned to use it for a while prior to putting the cover back on to see if it starts to fail again but I can't explain why it freezes up on Photoshop. One other thing. I now get a fault occasionally that says Windows Corrupt FIle - Exception Processing Message C0000102, Parameters 75b6bf7c 75b6bf7c 75b6bf7c 75b6bf7c I looked this up on Google and found a solution posted to run SFC /SCANNOW. It brought up a window that says WINDOWS FILE PROTECTION at the top and in the box it says Please wait while Windows verifies that all protected WIndows files are intact and in their original versions. (sounds like I may be undoing some updates). I had to insert the original windows XP disk. I will let you know if it gets rid of the error and/or the locking up problem. Dan