Just over a week ago, I finished my second new-build. It was working fine once i got into the OS. Usually took two attempts, where it would just hang on 'Verifying DMI data' - sometimes got past and booted fine, other times would just freeze up there. No happy beep either, but wasn't sure if I needed to sort out the internal speaker. Otherwise working well, and was starting to transfer stuff across from my old one.
After a week of really light use, its completely gone. Was shut down ok, a few hours later it wouldn't start at all. After pressing the power button now, the case fans turn on, the cd-rom light flashes briefly, and that's it. The power cuts out, and then it seems to loop and try to start up again continously. I have to turn off at the mains/power switch on the PSU to stop it.
No chance of even changing settings as it only lasts a few seconds, the monitor doesn't even pick up a signal to get out of energy saving mode.
A bit of research seems to say it must be the mobo or psu as it happens so early. I don't want to go replacing everything as i've already broken the bank. I've checked for bad connections but can't see anything wrong.
Possibly not, its a couple of years old and built on a budget. I'm trying to find out what it is now (any easy way to do this?? It feels like it should be something really easy to do)
I found this in another thread -
"The paperclip trick on the power switch leads can be used to verify if these lines are shorted (or open). If they are shorted, the usual symptom is the PC will power on for 4-5 seconds, then shut down again.
If the system powers on long enough for LEDs to flash and fans to flicker, then shuts off, this symptom suggests a short-circuit somewhere"
I had a similar issue with my first system build. My power supply was DoA/Shorted out. I RMA'd it got a new one everything was ok after that.
Only other thing I can suggest is to unplug everything try the paperclip trick.
If it spins just fine then plug in your mobo and boot up again. If it is still giving problems I recommend just trying a different power supply (may be cheaper than mobo).
When this happened to me I did the paperclip trick and it was my power supply that was screwed up.
Ok, so I've unplugged everything except the mobo, memory, and cpu/cpu fan. Still starts up for a few seconds, then cuts out (can tell best from cpu fan). LEDs on the board for cpu load are lighting up - does that mean cpu is ok?
Rotated the two memory mods, one at a time. No change there.
Where now? Paperclip test? Shoving a paperclip into the psu fills me with dread to be honest...
PSU's, unless totally fried, will boot, do their own self-test, find, say, the 12v rail out of spec and shutdown to protect the end equipment. So what you are seeing is not unheard of... If the paper clip shows no issues, next test would be to see if it can spin a HDD. That will put a load on the 12v rails. (no paper clip for this test)
If you have a multimeter, you can do a rough checkout of a PSU using the "paper clip trick". You plug the bare PSU into the wall. Insert a paper clip into the green wire pin and one of the black wire pins beside it. That's how the case power switch works. It applies a ground to the green wire. Turn on the PSU and the fan should spin up. If it doesn't, the PSU is dead. If you have a multimeter, you can check all the outputs. Yellow wires should be 12 volts, red 5 volts, orange 3.3 volts, blue wire -12 volts, purple wire is the 5 volt standby. The gray wire is really important. It sends a control signal called something like "PowerOK" from the PSU to the motherboard. It should go from 0 volts to about 5 volts within a half second of pressing the case power switch. If you do not have this signal, your computer will not boot.
Unfortunately (yes, there's a "gotcha"), passing all the above does not mean that the PSU is good. It's not being tested under any kind of load.
When the switch on the back of the PSU is on, a small power supply inside called the "Standby Power Supply" is on. This is what turns on any LED's on the motherboard even when the computer is off. Unfortunately, this does not mean that the PSU is good and you have power going to the motherboard. This little power supply is completely separate from the main circuits that actually power the computer.