NO Signal on monitor

[Cathy Price]

i have an intermitted issue with my pc and monitor where the monitor will show a no signal message before  just going blank - I the pc them seems to make a whirlling noise.

i have swapped out hdmi cables, monitors (same issue on both) swapped to a lower graphics card thinking it may be the power supply not being grunty enough) nothing makes a difference has anyone had this issue?

[Brian]

Some thoughts...

• Hmm...it might be the motherboard, specifically the capacitors on the motherboard. Those are the things that look like water towers in a city. You might have to pop open the cover and with a flash light, go looking for them. I know, at this point you are wondering why you are doing this and WHAT are you looking for. Basically, you need to see if there are any "Poofy" Capacitors or ones with goo coming out the top. You want these cylinders or things that look like batteries to be straight on all sides. If any are budging or are "Poofy" or have the Electrolyte Material coming out of them, that's your issue. This web page has a really good photo of what I'm talking about. The four Capacitors on the left have the "Goo" coming out of them, and the ones on the right are "Poofy." They really need to be dead straight on all sides and have a flat top. Here is another good photo of a bad Capacitor with it being "Poofy" and not leaking all the way. Basically, it looks like a marshmallow instead of a metal cylinder / Coke can.
  
  Now, if this is the case, do not touch the capacitors or the goo. Just leave them be. If you do have something like this going on, I would backup-backup-backup ALL of your important files, all of your actions, your e-mails, receipts login info for various things, etc.,etc...while you still can.  In fact, I think you should do that now, regardless. If you do have bad caps, you are looking at replacing the motherboard, or buying a new computer. While it's true that the motherboard can be repaired, most local places do not do component-level repairs. 
   
• It is possible that your Power Supply could be under-powered since you are driving two monitors, and the graphics card has to work a little harder. Does things stay on with just one monitor plugged in? It also could be just a bad power supply.
   
• You could also have a crap ton of dust blocking the cooling vents and you have an over-heating issue. This is especially true if anyone smokes around the computer, it's in a high-traffic area that has lots of dust or have pets. Over the years, I've seen all sorts of crap in computers. In fact, I just resurrected an OLD UNIX Server a few weeks ago and it had about and inch of dust inside; I had to take it out side to get rid of the dust, and yes...I did create a Mushroom Cloud. I've also had dead mice in computers and have found a bunch of other stuff over the 27 years I've been a Tech. Even if you think you are a "Clean Person," you'd be surprised on just how much dust / crap gets sucked into a computer. Especially if it's buried under the desk. Oh! One more thing. This is also related to a heat issue. Are all of the fans spinning and you have good airflow?
   
• Speaking of an heating issue, your thermal paste that is between the cooling block / fan and CPU could be completely dried out and the CPU is overheating. That is totally repairable, but I'd have a tech-savvy person do this (or one who builds computers) as too much thermal compound is just as bad as too little.
   
• Final thought: It might be your surge protector. How old is it? More than 5 years? What happens when you plug your computer directly into the wall or use another outlet/circuit in your home? Better? Same?
   
• Check your Power Settings in your Control Panel. Is your computer going to sleep and just not coming out of it? The whirrling noise has me leaning towards a hardware issue at this point.

Basically, we need to trouble shoot. I don't think this is something like a bad Windows Update screwing things up, but something is wrong with the hardware. Again, if you haven't backed up, now is the time to do so. Just in-case things really go "Ka-Plooey" and you can't retrieve your data.

[Cathy Price]

Thanks Brian,  I will take it apart tonight and have a look, I did order a new power supply as well so fingers crossed it will solve it - it has already been dusted out no dust there now - there was a bit of dust in there but not much.   fans are spinning and have good air flow..  did check control panel its not going to sleep..