I just bought a new motherboard, installed it and it powered up ok for a few seconds (cpu seemed to be running fine) then i turned it off and put in my graphics card and modem. Then i powered it up and noticed that the cpu wasnt running and that a tiny amount of smoke was comming from a chip on the motherboard. Does anyone know if this is a power supply issue, ie. its putting too much power through the computer? cheers

When I read your first post, I was thinking that perhaps a cooling fan inside might be bad and making that noise. Depending on the processor, fans can be in the power supply, in the case, and on the processor chip itself. If there is one on the processor chip and it fails, you risk the chip overheating and damage.

Then when I read your second post, things look worse. SMOKE is not a good thing. It means that something in your circuitry is pulling way too much current, overheating, and subsequently smoking while it destroys itself. By the way, any amount (tiny or not) of smoke is a bad sign.

When you purchased the replacement power supply, did you ensure that the specifications MATCHED your PC? Not all power supplies are the same. If you didn't do this, do it now and don't power up again. Check that the new PS output voltages and pin assignments are identical to the old one. If you put the wrong voltage onto a bus, things smoke.

Were the motherboards the same? Does the new PS match the new MB? Look at the old MB closely. Do you see any signs of overheating (discoloration, bulging, burnt marks, etc.) on any of the components? Check the processor chips especially.

I don't know what could have caused your PC to turn on all by itself, unless you had last done a "restart", and when you shut it down did not change the selection to "shut down", but simply clicked on the OK button and walked away before the shut down cycle finished.

Thanks mate but i have pretty much sorted out my hardware problem now by installing another new motherboard and a new power supply and it works fine. But when i start it up it just gives me the message: DISK BOOT FAILURE, PLEASE INSERT SYSTEM DISK AND PRESS ENTER. Before this message appears I can push Tab and enter windows as normal, but if i miss it i am stuck with this message. Does anyone know why it isnt booting off the HD? thanks

maybe your hard disk is not connected to the ide channel correctly. try ensuring that the ide cable is in the right way round and is pushed home at both ends. if its even slightly loose the pc will moan at you until you put it right.

you could also have faults in the ide channels on the motherboard itself.

your problem is you made changes to your system by replaceing and installing new hardware to your system.

one thing you can check is the bios and see how your system is setup when booting up.

also you might need a system boot disk to get it running again.

here is a site where you can download a new bootdisk for your system.
place the disk in your floppy disk and bootup.
also have your windows cd handy just in case you have some missing or corupted files that need to be updated.


http://www.bootdisk.com

see if this helps.

yeah removing stuff like the power supply unit and motherboard can cause no end of troubles when it comes to trying to boot up a machine. windows will need to redetect your systems hardware configuration and therefore will most likely need to reformat your hard disk. if theres any data there that you need then install the drive as a slave drive in another machine and attempt to copy the data off the disk either to the master hard drive or to removable media

See if the boot device in your bios is set to your current hard drive ..
If it is ... then try unplugging the cd rom and boot..

got it working, just had to change the primary boot to the hard disk in my bios. TYVM to you guys for all your help

no peoblem.. glad we could be of assistance