[Repete456]

Hi, I have been reading this forum for some advice on solving my motherboard problem and thought it was worth noting my findings for anyone else with similar issues.

For a number of months on and off, occasionally the system would not start up with no beeps and nothing on the screen. After a few reset attempts, it would come good, so I had to leave it as it would then work fine which is unsuitable for troubleshooting.

Anyway, today it was in standby from last night and would not start at all. So, I ended up disconnecting all peripherals except the CPU, Memory and Video card. Nothing would happen, no beep, no video, nothing. Swapping the CPU, memory and video cards made no difference, so I ended up installing the HDD into another system and reconfiguring it to suit the different motherboard. This gave me some time to research and test.

Connecting the information that I found here with the support pages at ASUS, I removed the battery and cleared the CMOS, but this did not seem to make any difference. As this second hand system is a few years old, While I had the battery out I checked it with a multimeter and found that it had a reading of 0.8mA. I had a used one which had ~3.0mA, so I inserted into the battery slot.

However, the system would not start or beep, but after a couple of resets and some more thinking time, the screen lit up and I was able to get into CMOS. The thinking time would have been between 30 and 60 seconds, possibly more. During some of my testing with parameters, after save and exit, I got a warning about CMOS checksum failure requiring me to install and insert a floppy disk. I cleared this with another CMOS reset and reconfigured the CMOS again. Subsequent restarts still work, but I will check it again in the morning to see that it is alright after some time off.

The important thing to note here is that changing the settings in CMOS for the memory and fan operation etc, get invoked after save and exit, so this is something to consider when having memory issues requiring CMOS clearance. Additionally, there is quite a lag time before the screen lights up when there is a problem with the CMOS settings for the memory, so patience is the key.

Furthermore, get a cheap multimeter to check your batteries so that you can eliminate these problems before they occur, during your regular preventative maintenance.

Thanks

Edited by Repete456, 10 November 2009 - 01:51 AM.

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Update, forgot to mention that I checked the BIOS chip (which is the only one that is in a socket) and a gentle push resulted in a click, meaning that it was not seated properly. However, this did not appear to have made any difference, but is also part of a normal preventative maintenance procedure, so was worth checking.

Additionally, subsequent testing has proven that the system is starting fine, so I have commenced reassembly, but will reinstall the OS hard drive in the morning to verify that it is all working properly.

[Repete456]

Update, forgot to mention that I checked the BIOS chip (which is the only one that is in a socket) and a gentle push resulted in a click, meaning that it was not seated properly. However, this did not appear to have made any difference, but is also part of a normal preventative maintenance procedure, so was worth checking.

Additionally, subsequent testing has proven that the system is starting fine, so I have commenced reassembly, but will reinstall the OS hard drive in the morning to verify that it is all working properly.

[Repete456]

I have finished reassembling the system (installed the HDD, second video, second DVD burner & RAM) and it started fine, made some adjustments to the BIOS, installed the connections and powered it up.

Now that the HDD is installed, the system speaks to me advising that POST completed and it is starting the OS (...I might have to turn it back off again now :-)!

One modification that I did make was to install a small heat sink with fan on the fanless motherboard heatsink just to give it a boost, as our weather is warming up.

Just a note that my PSU is a thermaltake 430W unit and has been/is coping fine with the workload of the system. I am also monitoring the temperature of the MB, CPU and CPU fan speed having set the BIOS to cool 'n quiet. With the large chassis fan running at full speed, there is still very little noise coming from the system and the CPU fan speed is around 1400 RPM, keeping the CPU temp at about 35C. During data retrieval, it rises a little but as I said this is not a high workload system during the day.

Please let me know if you have anything to add, advice or comments.

Cheers

[jtscustomcomputers]

Repete456

If you experience problems in future be sure to run a test with a different power supply if you have access to one. ATX power supply problems are not always so obvious.

[Repete456]

Thanks, JT, my oversight, I did test it with another power supply to the MB +CPU +RAM & Video, but that made no difference either.