Computer will restart fine, but if I shut it down it will not start again???

[sowak]

Here is the deal. I am fixing a computer for a family member. It is an Emachine T1742. Capacitors on the MB popped, so I replaced the MB with the closest match I could find, an ASUS P4GV-LA. I installed the MB, booted up the emachines restore CD that has Windows XP on it and did a fresh install. Everything worked fine. I shut the computer down for the night to get some sleep.

The next day, I try to turn it on and nothing. No power, no fans, NOTHING. I checked all of the connections and they were good. Finally, I cleared the CMOS and it started back up. Windows loaded, and I fully updated Windows to SP2 will all available updates. During this process, Windows had to restart itself many times. It did and everything went great. If it had to restart, it would power down and restart back up quickly and I would pick up where I left off updating windows.

Also, I looked for a BIOS update for the MB, but I could not find one. The current BIOS version is 3.03 with a date of 8-31-2004. I powered it down and tried to start it back up. SAME THING. Nothing, no lights, no fan, no power at all. I clear the CMOS and it starts right back up and loads Windows. It is stable with no problems while running Windows.

I have a pretty good amount of experience with PC's, but I have never experienced this, read about it, or heard about it. ANY IDEAS? Thanks in advance.

Fred Meyer

[GX1_Man]

eMachines have notoriously poor power supplies. I would try another one of sufficient wattage for a test. Please post back.

(Could that be what killed the previous MB? I wouldn't be surprised at all.)

[sowak]

The power supply has been checked and is good. Just to make sure, I reproduced the problem with another good working power supply. Any other ideas?

Fred

[GX1_Man]

Could the MB be shorting out on the case? Recheck all of the standoofs.

[sowak]

I just double checked the standoffs. No problems there. Same problem.

[Raptor]

Restore CD could have been tailored to work with your other mainboard resulting in driver conflicts.

[2k_dummy]

How old is the cmos battery? Also check that the fans are clean and in good condition. In some machines, if the heatsink fan does not start up immediately you will get an immediate shutdown or no startup at all.

[sowak]

Restore CD could have been tailored to work with your other mainboard resulting in driver conflicts.

I have thought about that, but it seems odd that I can boot into Windows and it runs great. Restart and it still works great, no conflicts. But, if I power down and then try to  boot up again, NOTHING. The CPU fan will not even turn. Odd. Thanks for the input.

[sowak]

How old is the cmos battery? Also check that the fans are clean and in good condition. In some machines, if the heatsink fan does not start up immediately you will get an immediate shutdown or no startup at all.

CMOS battery reads 3.1V. The fans are clean and working great.

[Raptor]

Looks like the PC is overheating and shutting down to protect it self. Did you make sure all the heatsinks are fastened and that the PSU is strong enough as suggested earlier on?

[sowak]

Looks like the PC is overheating and shutting down to protect it self. Did you make sure all the heatsinks are fastened and that the PSU is strong enough as suggested earlier on?

The PC is not overheating and is not shutting itself down. The heatsinks are fastened and the PSU is in excellent working condition and is strong enough.

The PC only shuts down when I shut it down using Start>Turn Off Computer>Turn Off. When I do this, it will not start back up. The on/off switch has no effect at all (yes, the switch is good). So, I unplug the PC, clear the CMOS, and plug it back in. When I plug it back in, it starts fine and runs fine. I do not have to use the on/off switch to turn it on after clearing the CMOS. I plug it back in, and it starts right up.

 If I use Start>Turn Off Computer>Restart, then it restarts right back up with no problems.

[2k_dummy]

Check the on/off switch and make sure the leads have not been reversed.

[sowak]

FIXED IT! I moved the power button from the power button pins to the reset pins and it now works. I can shut it down and restart it without a CMOS clear using the on/off switch. I have never heard of something like this. Reset pins instead of power button pins? CRAZY. Thanks for all of the advice!

Fred

[Raptor]

You obviously did not connect the leads properly when installing the new mainboard..

[martinmm]

just 2 cents worth. i noticed no one has mentioned here the BIOS setting being changed from install from CD to what HDD should it start from