[Locla]

Hi there,

 

I'm having a bit of a bad day today, my PC was working fine when I left the room, when I came back it was dead. Infuriating because there could have been some kind of clue in the death, a blue screen, a noise, anything, but I was away for 5 mins and that's when it happened. 

 

I've done a breadboard test with just the 24-pin mobo and 12V CPU connectors in, and I'm getting no beep codes, display, or POST. The PSU and CPU fans spin for a minute and then it powers of. I'm running an ASUS P8Z77-V LK with an EVGA Supernova NX750B PSU. The chip is an Intel i5-2500k (not OCd). 

 

With the breadboard test the CPU and PSU fans spin but there is no power to any of the USB ports. I can have a SSD plugged into the PSU, but when I swap it for a HDD the power shuts down about a second or two after it starts. When I try to plug my GTX 970 into the PSU, everything dies after less than half a second. The green LED for mobo power comes on, and there are a couple of red LEDs that light up when I flick the switches (GPU booster, EPU). When I plug my PWM fan hub into the CPU_Fan all the chassis fans spin too. It also stays on with a DVD drive connected to the PSU and mobo, I was able to open and close it.

 

For years I had an old 2004 Dell desktop lying around and I could have used the proprietary PSU just to test it. Guess when I finally took it to the tip? Yesterday. Infuriating. 

 

The EVGA PSU is the only new thing I bought new for my build (except for a Phanteks case) but its 3 year warranty expired 3 months ago. (Inf- you get it.)

 

Asus provides info for beep codes, but regarding no beep code at all it just says to contact ASUS for further inquiry. (Which suggests it could be any of the parts in the title).

 

It could be any one of the parts, I just don't know, do these symptoms point to one or the other? The way I could go about it is just to buy cheap replacements for each part in turn, to find out which one is at fault. You can get cheap 750w PSUs for less than £30, although I wouldn't want to run my PC with one on a long term basis. You can find either the motherboard or CPU, used, for about £30. 

 

Please let me know which part is most likely to be dead, and I'll start with that one. Can't believe I threw away that old massive proprietary PSU yesterday. 

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The PSU is the most common thing to go first.

[SpywareDr]

The PSU is the most common thing to go first.

[phillpower2]

Asus provides info for beep codes, but regarding no beep code at all 

 

 

Don`t see an onboard speaker on your model of MB when checking the Gallery here

 

Did you fit a speaker when you did the build.

 

Has the board ever given out a single beep once the power on self test (POST) had completed.

[Locla]

Thanks SpywareDr, I am leaning towards the PSU myself tbh, even though it had plenty of headroom in my system and hasn't been stressed from OCing.

 

phillpower2 it's true that it didn't come with a speaker, I think it was you who suggested I buy one separately when I did the build over 3 years ago! It's been booting up with one beep ever since, until today. 

 

Thank you both for your responses btw

[phillpower2]

phillpower2 it's true that it didn't come with a speaker, I think it was you who suggested I buy one separately when I did the build over 3 years ago

 

 

You have a good memory Locla 

 

Would suggest disconnecting everything from the MB except the 24 + the 8 pin power connectors, the CPU cooling fan and the appropriate video port for your screen, remove the add on video card and all of the RAM, check for any blown, bulging/leaking capacitors, if the caps all look ok, reconnect the PSU power cord and turn on the power, if you get any error beeps it would suggest that the CPU, MB, PSU and RAM are ok and that the problem lays elsewhere, the graphics device being checked after the RAM in the POST would normally be the item of hardware that had the issue.

 

NB: When you post back with an update for us can you also let us know how many sticks of RAM you have.

 

You are welcome btw 

[Locla]

Hehe thanks

 

 

 

except the 24 + the 8 pin power connectors, the CPU cooling fan and the appropriate video port for your screen, remove the add on video card and all of the RAM

 

This is as I did, and no error beep of any sort was emitted. I also tested with both sticks of RAM (I have 2x4GB).

 

 

[phillpower2]

Based on the fact that you used to get a single beep once the computer had completed the POST but you now get none even when the RAM is removed it suggests a serious pre POST hardware failure, the highest failure rates are 1: PSU. 2: MB. 3: CPU.

 

When I plug my PWM fan hub into the CPU_Fan all the chassis fans spin too. It also stays on with a DVD drive connected to the PSU and mobo, I was able to open and close it.

 

 

Suggests that the PSU may be ok as the DVD drive requires a 12V supply from the PSU, have you checked the caps on the MB as was suggested, some info here to help with checking.

[Kemasa]

You can buy a PS tester, which is nice to have to check it out instead of just replacing it. It isn't perfect, but at least it gives an idea.

[Locla]

I had a thorough check over all the capacitors and the MB as a whole, following the info you provided, and I can't see anything that doesn't look right. I then breadboard tested it again with the video card plugged in, and still no beep codes but this time it didn't just cut out immediately, but ran through an endless boot and shutdown cycle with the fans spinning up on the GPU as well as the CPU and PSU. I tried with the optical drive also plugged in but that resulted in it cutting out as soon as it started. Unplugging the GPU but leaving the optical drive plugged in resulted in it going thorough the endless boot and shutdown cycle again. Interestingly, when I swapped the optical drive for a small HDD, it resulted in the immediate cut out. 

 

 

 

the highest failure rates are 1: PSU. 2: MB. 3: CPU.

 

This case may an anomaly to that rule seeing as both the MB and CPU were previously used, while the PSU was brand new. I got the MB for £35 and the CPU for £85 so three years wasn't a bad run, if either of them are the culprit. 

 

Thanks Kemasa, the PSU tester seems like a good idea, but I'm starting to wonder if I should just take this as a forced upgrade and move to LGA 1150, or 1151 if I can find a board with DDR3 support for my current RAM...

[phillpower2]

 I then breadboard tested it again with the video card plugged in, and still no beep codes 

 

 

Can I just check that you did fit a BIOS speaker yourself when you first put the build together.

 

This case may an anomaly to that rule 

 

 

Not really, your PSU is new and the MB & CPU used so you may suspect the MB and then the CPU but keep in mind that even new hardware can be faulty from out of the box new.

 

NB: Did not get the usual email notification of your reply but noticed your reply on the forum, not sure why it was there but checked the spam folder and there was your reply, odd    

[Locla]

Yes, the BIOS speaker has been in there since it was first built 3 EDIT: days years ago. Only a week before it died I had forgotten to reattach my keyboard USB, and it made a different error beep code because of that. 

 

I will be able to test the PSU early next week, as that's when my new parts arrive. Typical if it was to have gone, 3 months outside of the warranty. 

 

Spam foldering me already?    It's a bit of a waiting game anyway until the parts arrive Hope to update early next week. 

 

Til then

Edited by Locla, 04 July 2018 - 03:44 PM.

[phillpower2]

Yes, the BIOS speaker has been in there since it was first built 3 days ago. Only a week before it died I had forgotten to reattach my keyboard USB, and it made a different error beep code because of that. 

 

 

Thanks for confirming 

 

Getting error beeps when there was no keyboard attached confirms that things were ok up to that point and makes me suspect the MB slightly more now.

 

Spam foldering me already?

 

 

must have been yahoo having an off day as your reply #11 above was delivered to my inbox no problem.

[Locla]

Sorry- I meant 3 years ago, have edited. So roughly a week and a half ago from now is when I got the no keyboard error beep code. 

 

 

 

makes me suspect the MB slightly more now

 

I also suspect the motherboard. Just now, using certain methods (safe), I have firmly established that the processor produces heat (delta 10 degrees) when the MB power is shorted on. This to me suggests that (1) the MB is supplying power to the CPU, and (2) the CPU is also doing something with that power. I would have thought that if the CPU was the faulty party, it wouldn't be doing enough with whatever power is provided to produce heat. But of course I may be wrong; does this info suggest anything to you? 

 

Glad my responses are now being correctly relayed 

 

[phillpower2]

You were back in Spam Locla 

 

Hot CPU means that the processor is good as is the CPU socket on the MB, could be egg on my face here as it reverts back to a flaky PSU as being the cause.

 

No video with or without the add on video card, CPU getting power and no error beeps with the RAM removed does though suggest that the MB has issues.

[Locla]

I'm starting to think that I must like it in spam

 

Oh dear, well if it does turn out to be the PSU then my only unnecessary expense has been the upgrade to LGA 1150, which was going to happen sooner or later. Although later would have probably meant straight to LGA 2011 and DDR4, but I digress... as you say, the MB appears to have potential issues.

 

I repeat that the USB ports do not supply power to any devices. Also, is it worth mentioning that no power is going out from any _FAN on the MB except for the CPU_FAN? If it does turn out to be the PSU, I think I'll get a replacement with a longer warranty (and better efficiency). I'd still like to have the head room for moderate overclocking + D5 pump (Voltage: 8-24V (37W Max). I might also run a second GPU at some point down the line. Would you recommend Corsair HX750i? If 750W is too low I could get their 850W version, but it might be a bit overkill. They are rated platinum, have a 10 yr warranty, and are easier on the wallet than some of the stuff I've seen. I also wouldn't want to go with EVGA again so soon, if it is the PSU that has gone bust