My First Computer    

I acquired my first PC in August 2000. I wanted it to be most up-to-date so that it will not be obsolete in another year or so. I wanted it to run fast when connected to the internet. My friend introduced me to AMD 750 Mhz processor rather than Pentium III 800Mhz which he said was comparable. I hoped I did not make a wrong decision. It was running on Windows 98 second edition but not really good because the system often hangs when connected to internet. Sometimes, it just rebooted itself when disconnecting from internet. 

When the operating system of my PC changed from Win98SE to Windows ME, my computer often hangs too when connected to internet even for less than 10 minutes. There was a green strip at the top of the screen when the system hanged. Press Alt + Ctrl + Del has no response to bring up Close Program Dialog or to reboot the system. After downloading the latest modem driver from internet, the modem works fine and no more hangs. Initially I thought the Display driver does not work with Windows ME or overheating problem or hard-disk problem or system files corruption or faulty RAM chips but it was pinpointed to modem driver after many tests.

Now there is no such problem and I find that Windows ME is very good as there is "System Restore" capability which enable it to be restored to a stable state before the installation of new program or the like.

It was well known that AMD processor gets hot very fast and slow down the system. I use 2 CPU fans 6500 rpm each to cool the processor and another air intake fan for the casing. My PC runs at the fairly low temperature of 38 ºC. I modified the CPU fans myself from bushing to ball bearings in order to enable the fan to spin quietly at the peak of 6800 rpm.

My External USB Thundercom Mini Modem 56Uxs-DM (Download Now: Driver 1,726KB WIN ME) was damaged by lightning while the telephone line was plugged on to the modem but not connected to internet. To prevent from lightning damage, I use lightning protector MPS-2 and always unplug the telephone cable when not surfing internet. 

My Personal Computer is not the fastest computer of all. It is becoming obsolete as Pentium IV is already in the market. However, it still serves me well for MS Word, Excel, Outlook and MS Internet Explorer applications. It is comprising of the following components and systems:

Trouble Shooting -- System frequently hangs; low CPU voltage

Few months ago, my PC system frequently hanged and needed rebooting. What was the root cause of the problem this time? There was no green strip at the top of the monitor screen. System just frequently hanged. Was it the CPU that is faulty due to short life span for AMD Athlon Processor? It had been 5 years old and parts might have reached their useful economic life span. There are 3 main hardwares which may have contributed to system frequently hangs, identified as follows:-

1. CPU overheated; CPU fan is faulty;
2. DFI AK70 Rev A motherboard may be faulty. It may have open circuitry some where in board or certain capacitors are dead.;
3. Power Supply Unit (PSU) is faulty or poor connections such as from the Power Supply Unit to the Motherboard

The PC casing was stripped open, CPU removed and motherboard was closely examined for corrosion of the copper circuit. One or two dead capacitors were changed with similar capacitance. Then 2 CPU fans were cleaned and their speed were found normal. Then Power Supply Unit was measured for the 5 volts and 12 volts and opened up for cleaning its cooling fan. All components were reinstalled and the system was found working normal for several days. Then the problem cropped up again. This time PC casing was opened and checked for loose connections on the motherboard. First thought to be the loose  connection between Athlon processor and the Slot A mainboard but it worked well again after removing and reinstalling. PC Health Status was checked by pressing 'Del" key to enter to CMOS. The normal readings are as follows:-

CPU Temperature:    35°C/ 95°F

CPU (V)                 1.61V

+5V                      5.02V

- 12V                 - 12.77V

Now, the voltage +3.3V for CPU was found as low as 2.97V while other readings had not noticeable variation when system frequently hanged. Low voltage at CPU was pinned point to be the root cause of the problem. Why low voltage at CPU? I am not a computer technician but merely an user. My initial thought was to get a replacement for the power supply unit but the voltage output for 5 volts and 12 volts were measured and seemingly normal. Then shaking the connector between the cables of the Power Supply Unit and the DFI AK70 mainboard did the trick to bring back the voltage of around 2.97V to 3.10V. When the problem recurs, I know immediately where to tackle this time. PC Health Status will be checked first and there the +3.3V point for CPU will be found lower than 3.0V. Shut down the PC, open the PC casing, shake the power connector and reboot the PC. Re-check the CPU voltage and there the voltage returns to 3.10V. I wonder why the voltage is 3.10V and not 3.30V. Some day, I will get a new power supply unit and will find out whether a new power supply unit can fix it. Currently my PC works fine at CPU +3.10V but not lower than this voltage. If I got a replacement for power supply unit, the problem might be resolved, provided that the cables connector (24 pins plug) was properly slotted in otherwise the problem would remain and the PC might become a piece of junk. I hope to share this finding for those PC users encountering the same problem to resolve it within the shortest time and at minimal cost. 

DFI AK70 Rev A+ Slot A mainboard

DFI is one of the world's largest, oldest and most trusted manufacturers of motherboards. Based in Taiwan, DFI manufactures over 200,000 Pentium, Pentium Pro and Pentium II system boards each month. From April 1999, DFI even successfully launched the latest 810 motherboards for Pentium III.

DFI developed and produced P9-chipset motherboards in 1988, and designed the first motherboard series for 75MHz system in 1996. In 1998, DFI promoted its Super-7 motherboards with 100MHz FSB. DFI production history well represented the strong foundation in research and technology on motherboards.

The DFI AK70 is one of the board that  resembles the reference board from AMD. Probably one of the reasons why this board came so late is probably that DFI only release products that have bugs ironed out.