PC Diagnosis Confusion

[Veyron786]

So my dad brought me he's office PC last week to look at as it was not starting, I immediatly suspected PSU as it contained one of those crappy Case/PSU combinations. So I proceeded to test with my PSU from my PC. One first startup the PC still did not POST. I reset the BIOS and voila PC booted up straight into Windows.
Happily i proceeded to hunt down a decent quality low cost PSU for office use. I ordered a Corsair VS350 and when it arrived installed into the new machine.
And........ nothing.
The PSU was stuck in a restart loop, brings all the lights on but seems to go into some sort of protection mode and then restarts no POST. Once again i tried my own PSU, same result PSU keeps shutting down and starting up. I did some further diagnosis up to the point where I had removed the M/B from Case and had nothing but the CPU, RAM and two power connectors attached and shorted the Power switch Jumpers still no luck.
So I'm pretty much convinced the MB or CPU is busted but how do I know which one?

The board is an Asus P8B75-M LX and Core i5 3570 which is still perfectly capable of fullfilling he's needs.

I can still source a 1155 Motheboard if I search enough but what are the chances that the CPU is actually faulty?
I'd hate to buy another component and find that it still doesnt work.

Anyone have any suggestion for further diagnosis?

 

[ponder]

So I proceeded to test with my PSU from my PC. One first startup the PC still did not POST. I reset the BIOS and voila PC booted up straight into Windows.

I can still source a 1155 Motheboard if I search enough but what are the chances that the CPU is actually faulty?

Very slim based on the above.

Replace the cmos battery & reset again, replace MB.

 

[ODTech]

So my dad brought me he's office PC last week to look at as it was not starting, I immediatly suspected PSU as it contained one of those crappy Case/PSU combinations. So I proceeded to test with my PSU from my PC. One first startup the PC still did not POST. I reset the BIOS and voila PC booted up straight into Windows.
Happily i proceeded to hunt down a decent quality low cost PSU for office use. I ordered a Corsair VS350 and when it arrived installed into the new machine.
And........ nothing.
The PSU was stuck in a restart loop, brings all the lights on but seems to go into some sort of protection mode and then restarts no POST. Once again i tried my own PSU, same result PSU keeps shutting down and starting up. I did some further diagnosis up to the point where I had removed the M/B from Case and had nothing but the CPU, RAM and two power connectors attached and shorted the Power switch Jumpers still no luck.
So I'm pretty much convinced the MB or CPU is busted but how do I know which one?

The board is an Asus P8B75-M LX and Core i5 3570 which is still perfectly capable of fullfilling he's needs.

I can still source a 1155 Motheboard if I search enough but what are the chances that the CPU is actually faulty?
I'd hate to buy another component and find that it still doesnt work.

Anyone have any suggestion for further diagnosis?

I've never come across a broken intel cpu. I have broken one by not seating it properly though

 

[Shevach]

So my pc does this regularly after power hiccups. Not sure if you have tried this as it doesnt say or I dont see it at least. I have 2 ram cards. I take them out and swop them around. Pc starts immediately again. When I had only 1 card I just moved it into another slot. Problem solved. Hope you come right and dont have to spend unnecessary money. let us know if you solve the problem and what it was.

 

[LazyLion]

Yeah, try a new CMOS battery.
Also try updating the BIOS firmware.

 

[Veyron786]

Very slim based on the above.

Replace the cmos battery & reset again, replace MB.

That good to know thanks. I have tried a new CMOS battery and reset, no luck.

So my pc does this regularly after power hiccups. Not sure if you have tried this as it doesnt say or I dont see it at least. I have 2 ram cards. I take them out and swop them around. Pc starts immediately again. When I had only 1 card I just moved it into another slot. Problem solved. Hope you come right and dont have to spend unnecessary money. let us know if you solve the problem and what it was.

Tried that too, one thing i haven't tried was a different RAM module though because it has the same result even without a module installed, but maybe I should just to be sure.

Yeah, try a new CMOS battery.
Also try updating the BIOS firmware.

Can't get into POST to update BIOS, unless there's another way. The PSU literally comes on for 1 sec then restarts.

 

[Rickster]

Was their any lightning in the area recently?

 

[sajunky]

Can't get into POST to update BIOS, unless there's another way. The PSU literally comes on for 1 sec then restarts.

Do you really mean PSU restarts?
Do you see any POST message on the screen? Connect PS/2 keyboard (not USB) and watch keyboard lights. All lights should go on for a second if CPU starts and goes to the keyboard reset. It is on early POST stage before passing control to VGA BIOS.

In such cases a test card displaying the last POST error message helps to find problem. If you don't have such card,
plug very basic VGA card, so maybe you can see boot screen, so you could procede with setup and flashing.

Try also BIOS recovery procedure from the manual, but use the latest flash image. Gigabyte will do flashing even on blank screen, I don't know about Asus.

 

[Chevron]

So my dad brought me he's office PC last week to look at as it was not starting, I immediatly suspected PSU as it contained one of those crappy Case/PSU combinations. So I proceeded to test with my PSU from my PC. One first startup the PC still did not POST. I reset the BIOS and voila PC booted up straight into Windows.
Happily i proceeded to hunt down a decent quality low cost PSU for office use. I ordered a Corsair VS350 and when it arrived installed into the new machine.
And........ nothing.
The PSU was stuck in a restart loop, brings all the lights on but seems to go into some sort of protection mode and then restarts no POST. Once again i tried my own PSU, same result PSU keeps shutting down and starting up. I did some further diagnosis up to the point where I had removed the M/B from Case and had nothing but the CPU, RAM and two power connectors attached and shorted the Power switch Jumpers still no luck.
So I'm pretty much convinced the MB or CPU is busted but how do I know which one?

The board is an Asus P8B75-M LX and Core i5 3570 which is still perfectly capable of fullfilling he's needs.

I can still source a 1155 Motheboard if I search enough but what are the chances that the CPU is actually faulty?
I'd hate to buy another component and find that it still doesnt work.

Anyone have any suggestion for further diagnosis?

The crappy PSU took the MOBO with it when it died.

 

[furpile]

Can't get into POST to update BIOS, unless there's another way. The PSU literally comes on for 1 sec then restarts.

I had that with my previous Gigabyte Z68P-DS3 motherboard after one year. The warranty replacement did exactly the same after another year. Then I bought a different mobo. From what I could find on the net back then there were a lot of mobo's from different manufacturers that had this problem. Something to do with that chipset. I don't know if your B75 has the same issue, but the symptoms are the same. Just get another cheap mobo and it should be sorted.

Edit: This is what I am talking about.

 

[Veyron786]

So I've tried everything, pretty much given up now. Time to find a new LGA1155 board.