[Ste]

Hi, at the moment I have a problem with my main PC. A message on the monitor said ‘no connection’ or words to that effect. I checked the cable and display port connection which seemed to be OK. I tried an HDM connection but same result. I presumed it was either the monitor or the graphics card.

 

 

As I had this, my fallback PC at hand, I installed the graphics card from the main PC, connected the monitor, and of course, it works.

 

I now have the issue of deciding whether or not it is the main board on my main PC which has failed or the processor; though if there is the slightest chance it is something else I would be happy to hear it.

I have seen there are several used main boards for sale which are the same as mine but no new ones. I am willing to buy one if anyone can encourage me in that direction rather than me thinking the processor could be at fault. If a new board could fix it, I would be happy, but don’t really want to buy a processor too unless I have no choice. Help.

 

Details:

Asus SABERTOOTH 990FX AMD 990FX DDR3 USB3 SLI Crossfire ATX Motherboard Socket AM3+

 

AMD FX-8320 Vishera 8 Core 3.50GHz Processor FD8320FRHKBOX Socket AM3+

 

Corsair Vengeance LP DDR3 1600MHz RAM Memory

Running Windows 10pro

 

[Advertisements]

Hello Ste,

 

If you are getting a "No Signal" message on your monitor it normally means that the problem is with the source of the signal (GPU) or the cable that carries the video signal.

 

What about trying your fallback screen and its video cable while the GPU was in the first PC.

 

Other things that can influence the display behaviour are the PSU and the RAM.

 

We could do with knowing the brand and model name or number of the GPU, the PSU and how many sticks of RAM there is.

[phillpower2]

Hello Ste,

 

If you are getting a "No Signal" message on your monitor it normally means that the problem is with the source of the signal (GPU) or the cable that carries the video signal.

 

What about trying your fallback screen and its video cable while the GPU was in the first PC.

 

Other things that can influence the display behaviour are the PSU and the RAM.

 

We could do with knowing the brand and model name or number of the GPU, the PSU and how many sticks of RAM there is.

[Ste]

Hi, thanks for your reply. Sorry if I haven’t made it clear but the Graphics card is working fine in my second PC in conjunction with the monitor that showed no connection; so doesn’t that rule them out regarding a fault?

 

 

I was just hoping it could be something else and you mention the PSU and RAM.

 

 

At the moment I am waiting for some thermal cream to arrive as I thought it might be an idea to renew it, but after taking off the heat sink and cleaning up found there was no TC left. When it arrives, probably tomorrow, I was going to use only one stick of RAM to see if it works but otherwise I don’t know how to check it as with the PSU.

 

 

I did try my main PC with an old monitor but it had to be with HDM cable as the old monitor had no display port connection. (There was no signal but to be honest, I am not sure if I had changed the monitor option to the correct HDM output).

 

More details:

PC-bought bundle i.e.Main board with CPU and memory in place 2014

PSU Exel van 850w 180v-240v 5-8A 60/50HZ (Replaced/installed 2018)

Memory:Two 16GB sticks of RAM

[phillpower2]

Was it the original cable that was used and worked with the second PC or did you use the video cable from the second PC.

 

If the original GPU and screen are working with the second PC it could be the PSU and especially one that is of such poor quality.

 

PSU Exel van 850w 180v-240v 5-8A 60/50HZ 

 

There is one thing that is possibly worse than using a known poor quality brand of PSU and that is using one that is unheard of, for brands of PSU to trust and brands to avoid please refer to the links in my sig.

 

Clues to how bad the PSU is are the price, a total lack of any information on the spec anywhere and the following which is perhaps the most alarming;

 

 

Rated Power: 850W

Peak Power: 1050W

 

 

 

The above is from the PSU description here the figures are the most dishonest claims that I have seen for a long time.

 

It would have been wise to have left the heatsink undisturbed while you were troubleshooting this, we now have another possible problem added to the equation I`m afraid 

[Ste]

Hi, it is the original DP cable that is working. I am surprised that the problem may be the PSU but I admit I wouldn't know a good one from a bad one; not sure where you mean by 'sig' for the link to options.

 

Presumably you are suggesting getting a decent one before considering any other action? Which would you suggest for my system?

[phillpower2]

Sig = signature  PSU guidance - 10 stripe - Johnny Lucky - PC Mech - PSU Review Database PSU Lemon List Which power supply do you need?

 

A half decent PSU would cost more than double what the Excelvan 850W PSU costs atm.

 

I would not purchase anything until the thermal compound, heatsink and CPU cooling fan have been correctly reinstated and some troubleshooting done, have you cleaned the top of the CPU and the base of the heatsink properly using something like 90% alcohol/rubbing compound and a lint free cloth or similar Instructions for Arctic Silver Products

[Ste]

Hi, sorry for the delay, the Thermal Compound was late arriving. I have put the heat sink back now and tried the PC which has the same problem.

 

I noticed something I did not mention in my earlier post, and that is that the main PC on/off button 'light' remains fully on when the power plug is attached and cannot be used to restart or turn off the PC. I suppose this does appear to suggest the PSU as you say and I am thinking of buying a:

 

 

Corsair RM850x (2018) - 850W 80 PLUS Gold Fully Modular 

 

I would like to know if you think this should be the next step though no blame of course if there is still a problem especially as there is a 10yr warranty.

Edited by Ste, 24 July 2020 - 06:53 AM.

[phillpower2]

No worries Ste, I will forgive you if you forgive me 

 

Had to put in a long shift today so cocoa and bed for me now.

 

I would like to know if you think this should be the next step though no blame of course if there is still a problem especially as there is a 10yr warranty.

 

 

A PSU with a ten year warranty cannot fix something that is broken and being honest Ste to sort this out one way or another you will need to follow step by step instructions and then provide accurate feedback for us.

 

The following from your post #3 for example is of major concern'

 

At the moment I am waiting for some thermal cream to arrive as I thought it might be an idea to renew it, but after taking off the heat sink and cleaning up found there was no TC left

 

 

The following from my reply #6 to which you did not provide any feedback, 

 

I would not purchase anything until the thermal compound, heatsink and CPU cooling fan have been correctly reinstated and some troubleshooting done, have you cleaned the top of the CPU and the base of the heatsink properly using something like 90% alcohol/rubbing compound and a lint free cloth or similar Instructions for Arctic Silver Products

 

 

The proper cleaning off and likewise the correct reapplication of the thermal compound is vital for any CPU but with the FX series of AMDs CPUs even more so. 125W TDP but safe operating temps in the 60 to 65°C range means you have to get your CPU cooling spot on

.

[Ste]

Hi, yes I have followed the cleaning instructions for the heatsink and applied the thermal compound as recommended by help videos. I do not presume any expertise regarding this process though I have done it several times before.

I found that the PC is just as it was, showing no signal on the monitor and a solid light at the front on/off switch which does not respond to restarting or turning off the system. I am now wondering about the trouble shooting you mention.

[phillpower2]

We now know exactly where you are up to and can focus elsewhere.

 

Not sure what case you have so we don`t have the specs to check but brand name computers such as Dell and HP use the power button among other things to alert the user to possible problems, the light staying on normally means that there is a problem with the power supply but in this instance being a custom build it could also be a faulty case power button, the latter would not explain the lack of video though.

 

You never let us know what GPU it is that you have + we do not know what PSU is in your other computer but if it is good enough to support your GPU I would temporarily swap it into the problem PC for testing purposes, let us know if this is an option and we can provide some additional info for you first.

[Ste]

Sorry, forgot what might be the important bit. I presumed you where busy when I didn't get a response to my last message when I mentioned the Corsair RM850x, well, I jumped the gun and ordered one. I will wait for your reply to my last message before I install it. I am comfortable with having spent money on it as, at least I will have a good PSU even if I have to get a new mainboard or processor too but hopefully I won't.

[phillpower2]

If you do not have your MB user manual you can download it from here.

 

The present PSU had to go in any event so no loss there but you may have spent a fair bit more than what you needed to.

 

To the task at hand, I suggest that when you swap out the PSUs that you also disconnect the case power button switch in case it is faulty, you can then manually activate the PSU by shorting out the two pins that have been highlighted in the attachment below, your call on this and if you wish to just swap out the PSUs and leave the case power button for now it is understandable.

[Ste]

Hi, the PSU arrived quickly and I installed it today. Unfortunately the ‘No Signal’ problem remains the same.

 

 

I was unsure about how to disconnect the power switch and shorting out the pins illustrated (should the power be on when you do this)? So I just tried it as it was. All fans working, graphics card lit up but still a solid light at the switch which still does not turn off the power.

 

I’ll try anything you suggest if I can understand it. This is stretching my understanding of what the cause might be.

[phillpower2]

It may be wise to ask someone a bit more comfortable with working inside a computer to take a look at this for you.

 

To short the two pins you need to disconnect the case power button from the MB when the computer is disconnected from the mains, you then connect the PSU to the mains and short out the two pins as in the picture.

 

Only other test I have is to check the CPU and that involves removing the heatsink, turning the power on and off quickly and touching the top of the CPU to see if it is hot/warm, a cold CPU would suggest that it was dead.

[Ste]

Hi, and thanks for continuing with this. It is not that I am not comfortable working inside the computer, I just need to get the idea and procedure clear in my head. I have just watched a video of someone bypassing the on/off switch in the way that you described and am clearer now.

It will be ‘round two’ tomorrow and I’ll try it, and also the cpu check.

If there is nothing wrong elsewhere, should the system boot up as normal including the signal problem if the switch is at fault?

 

If the results of the cpu test are negative i.e. the cpu is cold after turning the system on and off quickly (is that all the time it will take?) I will be looking out for a replacement. If it is warm I presume the main board has a problem? I'll get back with the results.