Dead PC & No POST-CPU or Board?

[KingOfComputing]

I have a PC which has a i5 2500K on an ASUS P8P67 Pro, 12GB DDR3, AMD Radeon 6970 2GB, ASUS Xonar DS, 100GB STEC SSD, 1.5TB HDD, Pioneeer DVD RW and XFX 550 Pro PSU. I changed the PSU recently (according to advice on the PSU forum) as the previous one was getting real noisy. This was a couple of weeks ago. Anyway PC was working Sunday morning, was just browsing the web, so nothing stressed, and it suddenly shut down as if the power had been cut. I tried to turn it back on, nothing. Since then I have changed wall outlet, kettle lead, nothing. I have changed the PSU for a different one, nothing. Was able to put the PSU in a different system and it powers it fine, so not the PSU. Changed graphics card, removed non essential peripherals such as sound card, optical drives etc no change at all. Gone down to 1 stick of ram, tried even with no ram.... you guessed it: not a peep.

I have observed what happens when I switch on at wall, the green light on the bottom of the board comes on (presumably to indicate it has power) this is normal it did it when it worked. Then when I hit power button the power light on case flashes once, inside CPU LED flashes briefly and the PSU fan spins like a half turn, then everything is dead again and if I press power again I get nothing (until I power cycle it, then same thing). Normally when it worked the CPU LED comes on a bit longer, goes out then the system POSTs and continues to boot.

Have also tried removing BIOS battery in case the BIOS settings have somehow been messed up.

Luckily, I do have a second (Ivy Bridge, i3 3220) PC I can swap the CPU into assuming the i5 2500k will fit and run ok on an Ivy Bridge board? However, before I go to all the trouble of unmounting and remounting CPU coolers, is there any easier way I can know if my CPU or board is dead?

 

[satyamdubey]

ivy boards are socket 1155 and most will support Sandy natively. Your problem could be a short and can very well be a dead mobo. Due to all the failsafe measures available with cpus, they typically do not die before a mobo vrm.

If you can not find any dislodged screws that may be shorting the mobo, then you can assume the mobo to be dead. A cpu swap to test the 2500K is in order. You can reset the BIOS through the jumper to be really sure.

good luck
-Satyam

 

[KingOfComputing]

Thanks, I removed the CPU to swap into my other system today but decided to check the underside first to see if there was anything obviously wrong and I'm not sure if it is a problem but the underside does look quite obviously discoloured in places. When I look at pictures of them online as here: http://commons.wikimedia.org/wiki/File:Intel_core_i5-2500_bottom_IMGP9337_wp.jpg all the gold contact points are perfect shiny gold.

However my CPU has noticeable dull spots and some of the gold looks as if it has come/worn off and hence parts of it look more silver than gold. I have taken some photos, unfortunately it doesn't show as much but it's visible. See here: http://i236.photobucket.com/albums/ff137/stevenallickuk/CPU/CPU4_zps9f10470b.jpg and here: http://i236.photobucket.com/albums/ff137/stevenallickuk/CPU/CPU2_zpscc26777d.jpg

Is this normal wear and tear or could this actually stop it from working? Wary of testing it in another machine in case it could damage that motherboard and leave me with two dead PCs.

 

[satyamdubey]

that discoloration looks a bit like socket burn. the cpu might be damaged beyond repair. Does the mobo also have this discoloration?

 

[KingOfComputing]

The motherboard has no discolouration but I did notice that one of the pins looks to be missing. I have included a photo: http://i236.photobucket.com/albums/ff137/stevenallickuk/CPU/MBMissingPin2_zpscdffcd30.jpg if you look to the right of the central island there is a little black square where one of the pins should be. It's in the bottom right part of the photo. Another shot here showing the whole socket: http://i236.photobucket.com/albums/ff137/stevenallickuk/CPU/MBMissingPin_zps120e2101.jpg

If you look at it from a certain angle it looks normal but I'm pretty sure there is something wrong as it definitely doesn't look the same as the other pins. It seems I am not the only one this has happened to either: http://www.tomshardware.co.uk/forum/319353-31-lga1155-broken They have exactly the same problem to with regards to shutdown and no start up.

The thing is though if the motherboard is the problem why does the CPU look damaged as well? Could the motherboard failure have somehow made the CPU burn out?

Tonight I cleaned the CPU on it's bottom but it didn't fix the discolouration, might have got a little better but still not right. I refitted it all but, as expected still doesn't work.

Thing is should I try the CPU in my other system, as if it is damaged could it ruin the other motherboard? I really can't afford to lose ANOTHER PC.

 

[satyamdubey]

a faulty motherboard socket can overvolt/inconsistently volt and short the cpu. Since your last response, I've read up on this issue on other forums as well and the reasons vary but the most common one stated is a faulty socket. the cpu might be eligible for an rma if it is damaged and I think you should take that effort.

As for testing the cpu, I suggest not to test it in your good mobo. Some discoloration is observed on certain chips used over a length of time but your case looks more like damage than "expected wear". Although a modern dead cpu would normally make the mobo generate a beep code identifying cpu failure and would rarely "kill" it, there is always a chance that it may overload the mobo's vrm in a manner that it may cause mobo issues.

As, for the missing pin, does it seem like it has cooked a bit? black/blue tinted burn mark? it could potentially be the site that caused your cpu to have shorted as well.

 

[KingOfComputing]

Today I removed the CPU and tried it in my working Ivy Bridge PC. At first I thought it was working as that system did turn on and all the fans were spinning normally. Quite excited I hooked up a monitor but was disappointed to see no display. I tried both the onboard VGA and DVI. I also hooked up a dedicated graphics card in case the processor graphics weren't working but all gave no display. Also in hindsight I don't think it was even passing POST and there was no HDD activity and no beep noise to indicate successful POST and yes I did double check the speaker was in.

It is interesting that the other PC did switch on but I suspect it might simply not be sophisticated enough to detect a bad CPU rather than indicating any life left in the CPU. I also checked the bottom of the CPU that I took out of the Ivy Bridge PC and as I suspected it looked perfect indicating that something has gone wrong with the other processor.

Guess that means I have lost the board AND processor, £150 worth of hardware ruined, I'm totally gutted. Do you think I might get any luck with contacting Intel about the CPU?

 

[satyamdubey]

I am not sure whether you can successfully rma the cpu but you should try it. You did install everything properly and it was working earlier. You can argue that the cpu's life ended unexpectedly.

At this point, it would be a good idea to make sure it was not your new psu that killed everything. What make is it?

 

[KingOfComputing]

The PSU is a XFX 550 Watt Pro, was actually recommended on the PSU forum and I'm certain it isn't the issue as I tried it with my other system, which it powered perfectly.

I know it might sound a bit dumb but is there anyway the cooler could have caused this? It's a Corsair H50 (sealed water cooler). Is there anyway it could have leaked onto the CPU? though I didn't see any wet areas. I guess the other possibility is patchy contact with the CPU surface but again this didn't seem to be the case and I had it fitted VERY tight.

Have there been many cases of H50's leaking?

 

[satyamdubey]

I can not comment on how often the H50's have been known to leak but yes, if it did it could have caused the issue. In an ideal scenario, distilled water cannot harm a system in case of spills because although it may be slightly conductive, it's resistance would be too high for the voltages that cpus operate at.

Having said that, the moment water leaks on the board, it is not absolutely distilled either as it pick up contamination from the board. If you saw moisture around the cpu or the coolers contact pad, then yes there is a fairly good chance that it shorted the board and the cpu.

A cooler which can cause the board to bend/buckle a bit through pressure can cause shorts as the pin contact in this case can become uneven to the point that some pins might actually not touch the cpu's contact pads. This can cause dielectric breakdown of the air which causes sparks.

 

[KingOfComputing]

RE: The cooler: Well, I didn't see any evidence of water having leaked or wet areas or rust or anything so probably just me being paranoid about it. Guess I'm just not comfortable with water in such close proximity to electricity.

Anyway, while I decide what to do with the faulty board and CPU, decided to replace them as I can't afford to leave the system offline indefinitely plus getting either replaced is far from guaranteed.

As I obviously hadn't budgeted for losing a motherboard and processor I could only afford budget parts. I went for a Core i3 4130 and a MSI B85M-E45. I managed to get the board for £49 delivered on DABs and the CPU for £58 delivered, both brand new so pretty pleased with that. I know it might be a bit slower than the 2500k I had but at least it's the latest platform so I have upgrade potential and I have heard that in general usage the 4130 isn't actually that far behind the 2500k so I might well not even need to worry about upgrading (at least for a few years anyway). Plus the better power efficiency of the 4130 might save a few bob on the electricity bill too...

As the i3 4130 is a pretty low powered part I'll probably just stick the bog standard intel cooler on thus eliminating any potential for damage from the H50 or strain on the board, though I'm sure it's fine...

 

[satyamdubey]

I honestly feel for your loss but you did the right thing in going for a 4th gen i3. You won't miss two actual cores and turbo speeds that much and HT would bring some reprieve. i3's don't need high end cooling unless you decide to play around with bclk tweaks which is a waste of time and energy albeit fun, i guess.

good luck with your new purchase and i'd still urge you to rma cpu. who knows you might have luck on your side this time.

All the best
-Satyam