Black screen "no signal" after cleaning.
Solvedjeannets Posted messages 28329 Registration date Status Contributeur Last intervention -
Hello, having a high CPU temperature I undertook to clean my computer with a can of compressed air and to change the thermal paste, but once cleaned and reassembled the computer does not start. All the components light up but there is no beep and the screen shows "no signal".
I checked the assembly and everything seems fine, I don't think I damaged any components as I was careful while handling them.
I removed and replaced the motherboard battery and took out the RAM but it doesn't change anything.
If anyone has an idea of where this might come from, I thank you in advance as I am starting to despair.
20 réponses
good evening
have you tried starting without RAM sticks? normally your motherboard should emit a series of beeps or a long beep.
when you cleaned your PC, did you remove the RAM? maybe there was a poor repositioning of the sticks.
have you checked your video cable to see if it's properly connected?
did you disassemble your heatsink or water cooling to change the thermal paste? did you do it hot or cold?
kind regards
on a computer, if it doesn't fit, we don't force it.
when we don't know, we can't guess.
Good evening and thank you very much for your responses, yes I tried without RAM, there are no beeps and nothing changes.
Yes, for cleaning I removed the RAM, GPU, and heatsink.
I checked several times if everything was well seated and it seems to be the case.
Yes, the video cable is properly connected.
I did it while cold.
Best regards.
depending on your motherboard, the beeps may be replaced by an indicator light on the bottom of the motherboard.
if I'm not mistaken, you should have a RAM light, a CPU light, and a power light.
do you have these lights?
on a computer, if it doesn't fit, don't force it.
when we don't know, we can't guess.
Well apparently you don't have a warning light
Before the cleaning did you have a beep or not?
On a computer, if it doesn't fit, we don't force it.
When we don't know, we can't guess.
I really don't see what it could be. At first, I thought it was the thermal paste causing a short circuit, but I cleaned it up and made sure it's all neat, and that's not it. Or maybe a connector that's not plugged in properly, but after checking, there's nothing there either.
Maybe the graphics card isn't seated properly because it's quite big, but I get to the end of the slot, and it worked perfectly before, so I have no idea :(
Ok, so you need to add an additional beep to the "front panel" connector on the motherboard.
So it's not going to be easy to diagnose.
Do you know if your processor has an integrated GPU?
If so, try removing your graphics card and connecting to either the DVI or HDMI output on the motherboard.
On a computer, if it doesn't fit, we don't force it.
When we don't know, we can't guess.
Yes, unfortunately, we are blind to it; yes, she has one. I tested removing the GPU and connecting the screen via HDMI to the motherboard, but the result was the same.
ok so first, it doesn’t come from the graphics card.
That leaves the RAM, the CPU, and the motherboard.
silly question:
when cleaning, did you unplug the 8-pin connector next to the CPU?
another question:
how are your fans running? smoothly as usual or full blast?
on a computer, if it doesn't fit, don't force it.
when you don’t know, you cannot guess.
Hello,
By my intrusion, I'm bringing you something to look at for a minimum startup...
Are you sure the power supply isn't tripped?? Unplug the plug... then plug it back in.
+++ Minimum PC Startup +++
The motherboard is equipped with a BIOS... you received a manual with the motherboard... It explains how to access the BIOS (Generally, it's the Delete key immediately upon power on and before the end of the Logo) you have to be quick...
For now, I'm not talking about Windows... the goal is to get the PC running, not Windows, that will be later.
So if accessing the BIOS doesn't yield anything, you need to disconnect everything from your setup... leaving only the motherboard (with its processor and one RAM stick) connected to its power supply and the case's power button... And the wired keyboard, that's it...
No graphics card, no hard drive or SSD, no CD/DVD drive, no monitor.
Turn on the PC while carefully watching the keyboard lights... They should briefly light up, maybe even all three then one... and then you play with the Num Lock and/or Caps Lock key... the lights should change state with each press of the key...
If that's not the case, you need to take everything apart and go step by step, ensuring the correct connection of each component... be careful with the fans... the 4 or 8-pin connector above the processor PWR_CPU...
Yes, that's already something :) No, I haven't unplugged it, only the CPU fan.
They are running as usual.
Ok, how many RAM sticks do you have?
On a computer, if it doesn't fit, we don't force it.
When we don't know, we can't guess.
Did you try both one after the other?
On a computer, if it doesn't fit, we don't force it.
When we don't know, we can't guess.
OK, good. Yes, but sometimes we have fingers that linger or other things... that have nothing to do with it... and we end up causing breakdowns all by ourselves... that didn't exist before...
Safe travels..A+++