Computer completely dead. Suspect motherboard or CPU but not sure.

[kebas239]

I have an I7-3770 rig with a Biostar TZ77XE4 motherboard. Last week, my power went out twice in the same day; once in the morning and once late at night. The first time, after power was restored, I had no issues. The second time however, I was not able to turn the computer back on.

I started with the power supply and ran the paperclip and multimeter tests. The unit would briefly start, but not stay on. As a result, I figured the power supply became damaged and ordered a new one.

I installed the new power supply and went to turn the system on thinking that the problem would be fixed. I was wrong. I had the same result as before - completely dead computer. I did run the paper clip test with the new power supply and unlike the old one, it appeared to continuously run and put out the proper voltages. I am now thinking that more than one component was damaged in the power outage.

Here are the symptoms:

- The computer does nothing when pressing the power button. The fans don't turn on, the power supply does not run, there are no beeps and there are no codes displayed on the LED of the motherboard.
- When the power supply is plugged in and the switch on the back of it is turned on, there is a rapidly flashing red light on the motherboard. I read the manual/looked online and could not find out what it meant.

Here is what I've tried, which has had no effect on the issue:

- New power supply. I am able to get it to function when disconnecting it from the motherboard and using the paper clip method. The voltages are correct when measuring using a multimeter.
- Different power cord, different plugs. I had an old computer connected to it anyhow while waiting on the power supply, so I think it's irrelevant.
- Removing all components except the CPU.
- Replacing the CMOS battery and setting the jumper to reset the BIOS.
- Reconnecting all of the leads from the case (Power SW, Reset SW, etc.)

I am honestly not sure what else to try. I do not have a spare compatible CPU/motherboard that I can swap out to test those two components individually. I am thinking I will have to just order a new motherboard and pray it's not the CPU (which I spent close to $400 on when I bought it). Does anyone have any advice on another way I could resolve, or narrow down the cause of the problem? Thanks in advance for the advice!

 

[skitszo]

you didn't mention running one memory stick at a time.

and if you said power turned off.... were you surge protected?

next is replacing the motherboard....which you mentioned.



reading up on power surges.... the PSU should of prevented it from getting thru to your motherboard and CPU.....(should of)....

only other thing i could think of is a corrupt boot secotr on your hardrive... but you should still beable to see a bios screen of some kind. you could try using some windows install media to see if you get install instructions and boot up....


you didn't mention testing the harddrive on another computer...

 

[kebas239]

Thanks for the response skitszo. To answer your questions:

I tried running one memory stick (and swapping them out in different slots/combinations). I also tried having no memory sticks in.

I have all my components connected to a surge protector.

The hard drive(s) i completely disconnected. I did not connect them to other computers. But if the system is not turning on at all, that should have no effect right?

 

[skitszo]

try benching your motherboard....your kind of running out of options.

just having your power shut off is strange to kill your computer like that hardware wise.

well... at least run the hard drives as secondary drives on another system to see if you can verify they are working. Crystaldiskinfo and Hard Disk Sentinel are 2 programs you can use.. Hard Disk Sentinel just run the short self-test

can you pop a different harddrive on just to test if it will act differently...

 

[kebas239]

So..After buying a board on EBay that had defective pins and sending it back, I benched my original motherboard with only the processor and a stick of RAM inserted. To my surprise, the power supply and motherboard turned on. I plugged in my video card and then - dead. The video card, when plugged in, would not allow the motherboard/power supply to activate.

So I figured the video card was bad and would just use the processors video capabilities. After putting in all my components sans video card, I found that the system was dead again!!! Eventually, after unplugging all the various connectors, I found that unplugging the USB2 front header would allow the power and motherboard to turn on. The weird thing is, now, with the USB2 unplugged and the video card plugged in, it POSTS!

I have no idea what is going on with this thing, but thought I'd update that I got it to work in this way.