Is the CPU or motherboard fried?

[Bob Ghengis Khan]

My brother's had his new computer set up for a few weeks, but today sparks flew from the back of his computer. We replaced the power supply and disconnected everything (RAM, CD Drive, Hard Drive, Video Card) except the CPU from the motherboard.

I have taken my internal speaker (his case did not come with one) and put it in his computer to try and get some beep codes to come from his motherboard. I'm not hearing anything when I attempt to start the computer. I have tried removing the CMOS battery for a good 10 minutes or so and reseating it, and tried starting it without the battery in, not hearing anything. Just tried replacing the CMOS battery with a new one, that is not working either

The fans all spin.

Can anyone help tell me what to do now to test?

The motherboard is a Biostar A770E3. I don't know if the speaker is enabled by default in BIOS, he never had one in before

 

[jackschmittusa]

My guess is the mb. Could be the cpu too, but if it is, I don't see how the mb could survive what it took to take out the cpu.

 

[pcgeek11]

My guess is the mb. Could be the cpu too, but if it is, I don't see how the mb could survive what it took to take out the cpu.

9 of 10 Doctors say the MB is dead. Between the CPU and PSU the MB is by far the weak link.

 

[Bob Ghengis Khan]

Thank you.

 

[Loisal]

Computer stopped working after six months. It won't post. I get no beeps and no video. Already tried clearing CMOS by jumper and battery. Also, tried ...

 

[daw123]

Computer stopped working after six months. It won't post. I get no beeps and no video. Already tried clearing CMOS by jumper and battery. Also, tried ...

Does it actually switch on (HSF / case fans spin up) or is it completely dead?
If its completely dead, then check the ATX main and 12V CPU connections and case power switch connection on the MB to make sure there isn't a loose connection. Also check that the voltage switch is set to 110V (I'm guessing you are in the US - check that it is set to the correct voltage for your country). It may automatically adjust for the mains power supply, so don't worry if it doesn't have the power selector.

If the connections are okay, but the PC is still dead as a dodo, try shorting the PSU as described in the last item in the below link (with the main PC power cord pulled out of the wall socket to make sure nothing will be live whilst you do it):
http://www.duxcw.com/faq/ps/ps4.htm

Then after the PSU is shorted with a cable / jumper across pins 14 and 15 on the main PSU connector, use a multi-meter to test between any of the common pins and each of the 3.3V , 5V and 12V pins in turn to establish if you are getting the correct (or any) voltages from the PSU.

Note it is best to do the above with the PSU out of the case.

DISCLAIMER: DO NOT DO WHAT I HAVE DESCRIBED ABOVE UNLESS YOU ARE COMFORTABLE WITH DOING IT AND COMPETENT TO DO SO. I TAKE NO LIABILITY IF YOU ELECTRICUTE YOURSELF WHILST TESTING THE PSU.

Sorry about that, but I need to cover myself from potential litigious acts.

 

[gravator]

Some times if the Mobo fries then the CPU will get damaged.

 

[marmasatt]

Some times if the Mobo fries then the CPU will get damaged.

That's true but if you're not abusing it, it really takes alot to kill a CPU IMO. I would doubt it's the CPU.