How to DIY my own computer? Where to buy a DIY computer?

Computer Problems, auto shut-down, DIY repair, now not working at all.?

• Hello, I have a very detailed story before i describe the problem, so.... In 2005 Christmas, i got my first computer, it was top-of-the-line, running 3.2ghz and 320GB HDD, basically it was a huge step-up at that time for a home computer. In 2008 it gave a little bother, during usage it would auto-shutdown seldom. Over a long period it got that much worse it wouldn't get past the boot-screen before auto shutdown, then i decided to get anew computer. With that i got a laptop, as it was the era of laptops and it was perfect although it didn't meet my requirements. It ran 1.66hz and 160GB HDD. I haven't had bother with it yet. A few days ago, i went through some old storage and found my old computer. At this time I'm much more knowledgeable towards computers and managed to figure out the problem, it was the cpu, COMPLETELY mounded in dust, and it needed new thermal compound. I fixed it and ran it, it started fine but unfortunately it wasn't connected to a monitor, so stupid me decided to switch off by the mains before i hoked through the storage for the monitor. When i got back, and try to turn the computer on it started and stopped instantly. I tried a few things and then tried it again, not realizing i swtiched the voltage metre to 130, setting the whole house tripswitch off. When i finally restored power, and returned it back to normal 230v, the thing wuld boot at all, no sound, no lights, nothing. I think its the psu, and i think i need a new one, but just to double check. I can easily buy a new psu, but im not bringing it to a local technician, or computer repair store, simply as they're over priced, so please help me.

• Answer:

  One thing at a time. A new power supply will be needed. By switching to the lower voltage you blew either the internal fuses or the initial load transformer of the power supply. Do not attempt to fix. Just get a new one and make sure the voltage selector is correct before plugging anything in. Disconnect everything from the motherboard. Only things connected to MB should be Case, monitor, power, cpu. NO memory, NO disks, NO cards. Turn the power on and see if the motherboard POST (Power On Self Test) shows on screen. You may need to turn power on and off once or twice to see it. After POST press F2 or DEL (delete key) to enter the CMOS. Once in the CMOS verify that the processor is shown with all cores present. Turn the power off and insert the memory and repeat previous actions. Verify the amount of memory is shown within CMOS. Turn the power off and install the Hard Drive and go back into CMOS to see if it is seen. IF at this point no failures have been noted, then the CMOS should start the computer and the hard drive will start up allowing the operating system to start. Which will allow other diagnostics to be ran. IF at any point there was a failure. The last connected device is bad and needs to be replaced. If the computer will not POST after a new PSU then the MB is bad. Two options: keep the cpu and get a new MB or get a new MB/CPU combo. Good luck,