No display when PC turns on. No POST beeps but all fans and drives run

Think Tank · 03 Aug 2013

I'd appreciate some help on this one. I'm a bit stumped as to where to go from here.
I've had my PC for a year. It wouldn't wake up from sleep the other day - just a black screen. So I tried holding the power button. It wouldn't shut off. I had to use the power button on the back of the PSU. Now when I turn on the PC, I get no display, and no POST beeps (made sure the internal speaker was plugged in), but all of the fans work. The drives are spinning up just fine too. I still can't shut it off with the case button no matter how long I hold it in...which seems a little strange.

Tried:

Switched the monitor cable from PCIe video card to integrated card. No change.
Tested monitor on laptop using the same cable. Checks out.
Tested the PSU with a DMM. Checks out.
Tested the PSU with a DMM while plugged into MB. Checks out.
*I realize this could still be bad
Breadboarding. No change.
Re-seated the ram. No change.
Removed the only stick of ram I have. No change.
Swapped RAM with the other DIMM slot. No change.
Removed the HDD, DVD, audio, and KB & mouse. No change.
Inspected the motherboard for blown caps. Appears OK.
Removed the battery for ten minutes with the psu unplugged. No change.
Cleared the CMOS with a jumper pins for 10+ seconds...twice. No change.
Examined the heat sink compound and CPU pins. Checks out.

Throughout all of this I never got any beeps or display.

Haven't tried:

Using a different ram stick - don't have an extra.
Using a different PSU - waiting for a friend to let me borrow his on Friday.
Using a different CPU - don't know anyone with an AM3+ socket.

Specs:
Ultra LS 550 PSU
Transcend Information 8GB DDR3 1333
AMD FX-4170 CPU
ASRock 960GM/US3S Motherboard

Yes I realize this isn't a quality build in the slightest - but because all the pieces are in the same range of quality, I'm not sure what to suspect. I know the PSU isn't great, but what makes RAM any more or less of a culprit? Kindly don't knock my build too badly - I'm a college student on a budget.

ICIT2LOL · 04 Aug 2013

TT mate have you tried a memtest a you only have one stick?? might be as simple as that mate as you seem to have covered most other stuff RAM - Test with Memtest86+

You need to run it for at least 8 passes unless errors start straight away. Try the stick in different slots too- the testing is going to take you a long time unless like I said the errors start to come up fairly quickly.

Jacee · 04 Aug 2013

*tested the psu while plugged into MB. checks out.
**I realize this could still be bad**

You might also check if the power supply has gone bad. Do you have another one, that's a bit stonger?

ICIT2LOL · 04 Aug 2013

Yes mate if you do what Jacee suggests this might help.

https://www.sevenforums.com/vip/257690-psu-how-test.html#post2130086

&

PSU - Jump Start

Think Tank · 04 Aug 2013

@ICit2lol
I'm afraid I can't run the memtest as the machine won't display a thing. I know it's not just a display issue because I've tried both integrated, and aftermarket GPU's. Not to mention, the CPU won't even get warm when I turn it on so that tells me it's more than just a display problem. I don't have another desktop to swap the RAM module with and run the memtest with either. I did however run memtest86 a couple months ago overnight with no errors. Not that that means anything now.

@Jacee & ICit2lol
I'm afraid I don't have another PSU. But I will be borrowing one from a friend here soon to test it out with. What I did try though, was testing each pin from the PSU with a DMM (digital multimeter) while it was plugged in and turned on for any dead wires. The reason I did it plugged in was that it would be under load and be a more effective test.

Thank you for your feedback.

madcratebuilder · 04 Aug 2013

The lack of POST code beeps would make me look at the motherboard. A MB without cpu, ram and gpu should at least give you POST code beeps. Most bios well check cpu, memory, gpu then look for the OS. Your MB has "Instant Boot" could that have something to do with it?

Try resetting cmos and load system defaults in bios.

jimbo45 · 04 Aug 2013

Hi there
Remove everything except keyboard . Remove the mouse too. By EVERYTHING I mean EVERYTHING except the keyboard , MONITOR and obviously the CPU. Remove external graphic card if the mobo has a on board graphics. Remove also the memory sticks. By remove I mean just disconnect from the mobo.

Using the onboard graphics (if it exists) will give you a display if the external graphics card has gone defective.

Check of course that the CPU is mounted correctly -- normally once you've inserted the CPU into the MOBO you should never need to remove it again -- but if you still get no joy after all these tests then try and take it to somewhere who can check whether the CPU works -- some old fashioned small computer shop might work if your area is lucky enough to have one of these old type "Real Stores" !!.

Ensure also the power led and reset led switches are CONNECTED properly. Check also the monitor is connected PROPERLY too. Loose monitor cables can cause a problem too.

It's more common than you think also for external VIDEO cards to become defective - these can run incredibly hot and do break down -- if the MOBO has also on board video then we need to see if THAT works.

What we are trying to do here is just see if the basic MOBO will give you the BIOS display - even with 0K RAM in it you should get a display.

Report back on this test -- if there's no display here then the MOBO or Monitor is defective. It's rare that a monitor will become 100% defective but not impossible. I've assumed you've already ascertained that the monitor is OK.

If you DO get a BIOS display start replacing components one at a time

Connect external graphic card again (if you are using one) BEFORE the RAM.

If at any time the BIOS display fails again then you've identified the defective component. Re-connect the DATA drives before the OS for the purposes of this test. Once you have the data discs connected BEFORE the OS you should see some sort of message - No OS found - which is fine. Now finally connect your OS drive and if it's OK windows should boot up.

Without specialist tools this is the only way to diagnose the problem -- go right back to the start and eliminate all the components. The fact that FANS work leads me to believe that the PSU probably is NOT defective otherwise nothing would work.

Note also that if the CPU fan works that tends to imply that the CPU is actually working -- most Mobos I've seen where the CPU has gone defective just stay totally inert -- nothing works not even the fans - but that depends though on the design of the MOBO.

Cheers
jimbo

beauparc · 04 Aug 2013

I had the same problem a few weeks ago and basically did as Jimbo45 recommends.

I stripped everything out (and I mean every single little thing), cleaned and checked all the various bits and pieces, and re-assembled the machine.

It suddenly started working again and I have absolutely no idea why. I'm old enough to know not to ask questions - just accept that things sometime happen for no apparent reason.....

Think Tank · 04 Aug 2013

madcratebuilder said:

The lack of POST code beeps would make me look at the motherboard. A MB without cpu, ram and gpu should at least give you POST code beeps. Most bios well check cpu, memory, gpu then look for the OS. Your MB has "Instant Boot" could that have something to do with it?

Try resetting cmos and load system defaults in bios.

I have removed the CPU, RAM, and GPU (still has an integrated GPU) and still no beeps. I've removed the battery to clear any CMOS settings, as well as moved the jumper pin to clear the CMOS as per the MB manual. I can't access the BIOS settings as there is no video.

jimbo45 said:

Hi there
Remove everything except keyboard . Remove the mouse too. By EVERYTHING I mean EVERYTHING except the keyboard , MONITOR and obviously the CPU. Remove external graphic card if the mobo has a on board graphics. Remove also the memory sticks. By remove I mean just disconnect from the mobo.

I have done as you instructed. There is no change.

jimbo45 said:

Check of course that the CPU is mounted correctly -- normally once you've inserted the CPU into the MOBO you should never need to remove it again...

I examined the cpu for pin problems and thermal paste issues. Everything looked good.

jimbo45 said:

Ensure also the power led and reset led switches are CONNECTED properly. Check also the monitor is connected PROPERLY too. Loose monitor cables can cause a problem too.

Power, reset, and HDD LED are connected properly. In regards to the loose monitor cable, I see what you mean. But that wouldn't affect the absence of POST beeps, right?

jimbo45 said:

It's more common than you think also for external VIDEO cards to become defective - these can run incredibly hot and do break down -- if the MOBO has also on board video then we need to see if THAT works.

What we are trying to do here is just see if the basic MOBO will give you the BIOS display - even with 0K RAM in it you should get a display.

I've switched to the onboard VGA port and back, and still nothing.

jimbo45 said:

Report back on this test -- if there's no display here then the MOBO or Monitor is defective. It's rare that a monitor will become 100% defective but not impossible. I've assumed you've already ascertained that the monitor is OK.

I've tested the monitor on a laptop using the same cable. Works great!

jimbo45 said:

The fact that FANS work leads me to believe that the PSU probably is NOT defective otherwise nothing would work.

Note also that if the CPU fan works that tends to imply that the CPU is actually working -- most Mobos I've seen where the CPU has gone defective just stay totally inert -- nothing works not even the fans - but that depends though on the design of the MOBO.

Interesting.

On another note, I've dabbled in OCing.
A few months ago I tried OCing the CPU and RAM without adjusting the voltage, but reverted it back to stock after a couple of days.
I kept the onboard GPU OC'd for several months, without adjusting the voltage. It has been reverted since.
I SLIGHTLY overvolted the aftermarket GPU to prevent stability problems I was having. This is the only OC that I've not reverted to stock.

Think Tank · 04 Aug 2013

beauparc said:

I had the same problem a few weeks ago...I stripped everything out (and I mean every single little thing), cleaned and checked all the various bits and pieces, and re-assembled the machine.
It suddenly started working again and I have absolutely no idea why.

Haha! I was hoping for that outcome too! But this is day 3, and I'm losing my optimism.