No Video, No Beep, MoBo LED Lights on, Fans don't spin, on a Biostar TF7100P - M7

The issues of the Biostar TF7100P - M7 Computer comes quites complicated. It shows no display, No beep, both fans of the CPU heat sink assembly and power supply fan won't spin, but the motherboard LED lights on. We may suspect that the video card or RAM must be failing but we can't be too sure. A thorough check must be done at the beginning of every computer troubleshooting. Assessing the present condition of the computer and observing for physical damage and other minute details must be carried out before anything else. To find out how we made the fix, see below.

Date Fixed : 07.11.10

Problem : No Video, No Beep, Mobo LED Lights on, Fans won't spin.

Owner : Anonymous ( Church Employee )

Motherbaord : Biostar TF7100P - M7

Operating System : XP SP2

Technicians : Boging and Tomasito

URLs : http://clhidohsr.blogspot.com and http://clhidohardware.blogspot.com

INTERVENING FACTORS :

No Motherboard Support CD

OBSERVATION(S) :

Trying to turn on the system unit, the HDD LED on the front panel of the computer doesn't light. It has no display and there was no beep sound heard. The fans as we checked didn't spin. Our suspicion led us directly to the fault of the PSU but we cant be too sure.

TROUBLESHOOTING PROCEDURE :

- Based on our earlier observations, we need to open the side cover of the system unit to check if there are observable physical defects on the components of the motherboard like burnt capacitors.

Of course safety is primarily considered. So every time you need to open the system unit case, always turn off the computer and unplug it from the avr.

- With the side cover removed, we then inspected for physical defects. We did not find any burnt capacitor or other components showing bold physical defect. So we considered removing the data and power cables from the drives and turned on the system unit to find out if the drives might be shorted and have cased the problem. Again, there was no change on the status of the computer.

- As the system unit "runs" with power, there was this hardly audible whistling sound coming from within the system unit. We furthered our observation and sharpened our listening and finally found out that the sound came from the Power Supply Unit.

- So we opened the PSU and found 1 burnt and 3 leaky capacitors!!! The PSU is defective! So we requested the owner of the system unit to buy a new 450 W ATX PSU rather than to replace the capacitors. We may be able to change the components (the leaky and burnt capacitors) but I strongly recommend to replace it a new one.

- After the replacement of the PSU with a new one, the system then powers up and displays the POST. We turned off the system unit and connected back the data and power cables to the drives. Turned it on and found out that we were not able to boot up. The operating system was corrupted and needs to be fixed.

- Trying to fix the operating system using the XP Installation CD, it failed. We also tried Spotmau and still did not succeed. So we just reinstalled XP without formatting the drive and backed up the files.

- After the file backup, we re-installed the operating system with fresh install. Since there was no motherboard support cd, we downloaded and installed the drivers of this Biostar TF7100P - M7 motherboard from the their website.

- Problem solved!

SUMMARY :

- Stubborn problems are most probably be caused by the the Power Supply Unit ( PSU )

- Use you senses in troubleshooting computers, like to listen for abnormal sound. Most likely, a whistling sound is caused by a leaky capacitor. That capacitor might be from the motherboard or power supply and in our case, from the PSU.

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