Monday, September 27, 2004

Unusual PC Problems...Part 2

I just finish fixing two computers of Kuya Joseph and Ate Melinda. The first one, the IBM Aptiva, since it is a branded PC and not a PC clone, opening the casing was already a mystery. But since Garry was also here, and as Marcia and Emil have mentioned to me that Garry is also one kalikutero like me too, he saw the magic switch to open the casing.

New CDs seem to always have problems with old CD ROM drives and installation of Windows 98 on their PC just would not continue. I decided to temporarily attached my own CD ROM drive to be able to install everything well. I also installed Office 2002 XP with is as well as all the essential security softwares like Lavasoft’s Ad-Aware, Search and Destroy’s Spybot, JavaCoolSoftware’s Spyware Blaster and Norton SystemWorks 2003.

On the second PC, this was really messed up. It was 100% dead and only the power supply runs. And when this happens one or more of the following could be busted:
  1. Motherboard
  2. Power Supply
  3. Processor
  4. Memory
  5. Video Card
  6. One of the remaining hardware parts may be in conflict with other hardware devices.
To find out which one was the reason behind it, you can do a deductive process to narrow down to pin-point the real problem.

First thing I did, when I was still at Kuya Joseph and Ate Melinda’s place was take everything off and just leave together the Power Supply, Motherboard, Processor, Memory and Video Card and everything else was taken off. This is to cross out No. 6 probably cause: "One of the remaining hardware parts may be in conflict with other hardware devices"

And after doing that, it still did not work. So we are still left with the 5 probable causes of the problem which are:
  1. Motherboard
  2. Power Supply
  3. Processor
  4. Memory
  5. Video Card
Unusual observations were:
  • The power goes on once you plug in the computer. And the power switch does nothing. Then I noticed the switch was not plug in the right place on the motherboard.
  • The processor was a Pentium III and did not have any processor fan. This is the usual case with branded PCs but has an air tunnel going to some chassis fan. Obviously the processor came from a branded PC but since it did not have a processor fan with it but an air tunnel, when placed inside another casing, the air tunnel will not fit and it was attached only with a processor and heatsink.
  • The power supply was set to 220 Volts and no 110 Volts. And most probably it was not the original power supply not only because of the setting but also because it only has two screws on and were not even that tight.
  • The motherboard was for a dual processor type using slot 1 processors. And the plastic brace on the processor was cracked off because the heatsink was so big and seemed to be forced into the brace which was not for that heatsink.
With the limited supply of hardware testers I was not able to diagnose everything there and decided to bring it home and work on it during my free time which was basically during weekends. Since I was able to get a few parts from a garage sale recently, this gave me a test bed for the other parts on their PC.

My first best guess was really the video card and I also told Kuya Joseph and Ate Melinda that even when I was still at their place. So I took of their video card and tested in on my Motherboard and it did not work. Good I said to myself since I already knew the problem! It is the video card, so I used the video card that I got from the garage sale which is working fine and placed it on their motherboard. It did not work!

For sure their video card is not working since it does not work also on a already working computer. So this means nothing but not only the video card is broken. I was left with this list of probable defective parts.
  1. Motherboard
  2. Power Supply
  3. Processor
  4. Memory
I turned on their PC again and was touching the processor while it was on. I did not feel even a slight increase in temperature. The processor was cold which bad news, either processor or motherboard is broken. I took off the processor and placed it on the motherboard I got from the garage sale, and it worked! I tried it again this time using Kuya Joseph and Ate Melinda’s power supply and again it worked, so the power supply was also delivering the correct voltage to the motherboard.

That now just leaves me with this list of possible broken parts:
  1. Motherboard
  2. Memory
I tried their memory on my motherboard, it was dead. So confirmed, memory was also broken. I got an extra memory I have been using to test for so many years already so I know it is still running well and placed it in their motherboard. It worked for two restarts and on the third try, it was erratic already, sometimes working, sometimes not. I pulled the plug right away and didn’t even shut down well since I think the motherboard is screwing up my memory.

So the main culprit was the motherboard. That eventually messed up the memory, and video card. Good thing I got everything needed from the garage sale.

After taking out the motherboard, the motherboard had no insulation what so ever from the screws that normally should be insulated with a thin cork washer. Since I did not have any extra cork washers, the good old electrical tape could do the trick on the motherboard that I was going to install. So I told myself, no wonder the motherboard went berserk, there were no insulators on the screws. Although it is theoretically possible to do things without the insulators, since the contact points around the screw holes are isolated from the whole motherboard, it is still not a safe practice since any two soldered points on the motherboard, get in contact with each other through any conductor; it screws up your computer. So the lack of insulators for me is not the absolute cause of the problem but was my best guess.

Now after putting everything together, I was still cautious with the other hardware and was adding each part one by one and testing the computer every time, adding the floppy drive, the hard disk drive, the CD ROM drive, the CD/CDR/CDRW drive, the sound card, the zip drive, the LAN card and the modem.

Everything ran well except for two things, the hard disk drive and the zip drive. And they both were connected on the same IDE cable connected to the motherboard. Just when I thought my work was done, a new problem comes out.

I was able to find a 4GB hard disk from the computers for disposal that Papa got from their office, as well as a 100MB Zip Drive and everything ran well from there.

With everything running well, what parts were broken? The motherboard, the memory, video card, hard disk and zip drive. In my years of experience in fixing computers since 1996, I only had two instances in my life that had similar situations, one of them was I had an AVR that was giving of 300 Volts that burned a majority of parts and literally melted power adaptors of other hardware parts. The other situation was during a thunderstorm in the Philippines and a very bright flash of lightning outside the building of my computer shop followed by a very load thunder that followed right away busted a lot of things at my office, including the modem, telephone, and the phone line itself that the BayanTel people had to even come and fix the burned out phone line.

I think the electricity in the States is pretty stable that's why I haven't seen an AVR here, although there are power surge protectors instead. And one bad thing about Kuya Joseph's and Ate Melinda's PC was the power switch was not connected right, and whenever you plug in the computer, it turned on right away and the power switch was useless.

So now that all the test was done, this is now my final best guess of the real problem behind everything. Once the PC was plugged in, that's where the power surge comes in too since the power switch was not plugged on the motherboard correctly. And this power surge just started to burn everything up one by one. It's still a good thing though that they still have the modem, sound card, LAN card, CD and CD/CDR/CDRW drives, floppy drive, power supply and casing.

Now here are a few notes for my students and I know I said this in all my classes and will just mention them again just in case you forgot.

The power swtich, reset switch, power LED, HDD LED, keylock, and PC speaker connectors are all attached to some panel of a bunch of pins on the motherboard, and more often than not, the pins are confusing and arranged differently from one motherboard to another. And when fixing a computer playing around with these wire connections, here are the things you can do arranged from best to worse option.
  1. Use the motherboards manual. This is the best way to figure things out. On the manual, all connections are explained well.
  2. If the manual is not available, like if it is an old PC and the manual is in some missing in the univers, the next best thing is to go online and check the manual available at the motherboard manufacturer's website.
  3. If you do not have an Internet connection, like you went to the barrio of barrios in the deep edge of the Philippine islands and they asked you to fix some old Pentium 166, no manual and no Internet. Just look at the pins and on the motherboard there are labels in white text and just try to understand them well. And sometimes even with the labels, you still do not know where they are pointing to, but it is worth a try. Sometimes other motherboard manufacturer also do not post manuals of older models.
  4. If the motherboard does not have labels, this is when trial and error comes in. And making a mistake here will not do any serious damage. And if you think something is wrong with the power switch or reset switch upon turning on the power, unplug it right away and try again with the other pins. To them one by one starting with the power switch, then PC speaker (so you hear the POST), then reset switch, then hdd LED and Power LED, testing each time you plug in each one. If everything is alway working fine but the LED do seem to function right, unplug the LEDs and turn them 180o and they should work then unless you really plugged them in the wrong place.
This text was actually just intended to be part of a summary on what has happened to Kuya Joseph’s and Ate Melinda’s PC that I will email to them, and it ended up being a long article. So I decided to post in on my Students’ Blog since fixing any computer and telling the story of it will always help my PC Networks and Troubleshooting students and I know there were all waiting for the part 2 version of Unusual PC Problems. If you haven’t read Unusual PC Problems Part 1, click here.