Question No video signal, no POST without ram

[AllegroBarbaro]

Hi everyone,

I am having issues with my pc and I hope I can find some help here. I built this pc one year ago and it worked flawlessly until two weeks ago. Then, there was some issue with the video output to some crappy TV, and after a couple forced shutdowns it stopped giving out video signals.

I tried everything I could think of, then basically everything that is in the "no POST" sticky thread.

Current situation: I am trying breadboarding, just replaced the motherboard with a new one (but nothing changed). If I switch on with only PSU (either the old one or a fresh one I just bought), mobo and CPU I get no beep codes (and the led lights on the mobo don't light up). However, if I add the ram the led lights turn on and I get a beep code (1 long 3 short) which should mean AGP error (whatever that means?). If I add my GPU the same happens, same beep code, and the fan of the CPU only spins for a moment (I think it used to spin for at least a couple seconds on startup, but I am not 100% sure). I bought an old GPU for 15 euros off ebay (one that doesn't require additional power connectors) and with that one the fan spins loudly 3 times on startup, but I get no beep codes!

So, now I am very confused by all of this. Particularly by the missing beep codes. And I don't know what to try next. Should I buy a new CPU? Try yet another GPU? PSU? Unfortunately, I don't have access to parts from other working machines, like GPUs or PSUs, so I can buy new ones, but I'll never be sure they are not faulty to begin with...

Any help would be greatly appreciated!

My computer parts list:

mobo: Aorus B450 I pro WiFi mini-itx rev1.0
cpu: ryzen 5 2600
cooler: noctua nh-l9a
ram: gskill aegis DDR4-3000 8GB x2
ssd: m.2 sata crucial mx500, 1000GB
gpu: asrock phantom gaming Vega 56
old psu: corsair sf600
new psu: seasonic focus sgx-650
Monitor: LG 27gl850

 

[rocktalkrock]

Just to let you know, before PCIe slots were added to motherboards the graphics card was installed in an AGP slot. So the beep code you are getting indicates a problem with your GPU. Did you read each step in the "no POST" sticky thread carefully? There is very little you can do to troubleshoot your system that's not spelled out in that list. Can you be more specific about the video issues you first started seeing two weeks ago?

 

[AllegroBarbaro]

Hello rocktalkrock, thanks for the quick reply, I appreciate that.

I did read the "no POST" very carefully, and nothing helped, until I got to the last part where it is suggested to breadboard with only PSU and CPU, in which situation I get no beep codes, which should mean either of them or the mobo are faulty. I did try replacing the PSU and mobo, so this leaves out only the CPU. But, before buying another CPU I thought I'd ask, since I do get beep codes if I add the ram, and that seemed weird to me.

As for how the issues started, I had been using the computer with this TV as monitor for a few days, and the TV had the weird habit of switching off and on on his own every now and then. At some point, after such a switch off and on, the PC was freezed, so I forced shut and switched on again. After that I got no video output. I tried changing to another HDMI port on the TV, and I got signal again, so I restarted and updated the computer. After that, on the next start-up I got no video output again, and this time I couldn't bring it back by switching ports, cable, or changing to displayport. Actually, the HDMI ports on the TV now don't work anymore, even with other devices. The same tv does have a VGA port though, and that one works with other devices. My computer, on the other hand, didn't give any video output anymore, on any other display I tried.

 

[rocktalkrock]

Hello rocktalkrock, thanks for the quick reply, I appreciate that.

I did read the "no POST" very carefully, and nothing helped, until I got to the last part where it is suggested to breadboard with only PSU and CPU, in which situation I get no beep codes, which should mean either of them or the mobo are faulty. I did try replacing the PSU and mobo, so this leaves out only the CPU. But, before buying another CPU I thought I'd ask, since I do get beep codes if I add the ram, and that seemed weird to me.

As for how the issues started, I had been using the computer with this TV as monitor for a few days, and the TV had the weird habit of switching off and on on his own every now and then. At some point, after such a switch off and on, the PC was freezed, so I forced shut and switched on again. After that I got no video output. I tried changing to another HDMI port on the TV, and I got signal again, so I restarted and updated the computer. After that, on the next start-up I got no video output again, and this time I couldn't bring it back by switching ports, cable, or changing to displayport. Actually, the HDMI ports on the TV now don't work anymore, even with other devices. The same tv does have a VGA port though, and that one works with other devices. My computer, on the other hand, didn't give any video output anymore, on any other display I tried.

I think it's unlikely the problem is your CPU unless it has bent pins or the cooler is not installed properly. Does the video card show any signs of life, fans spinning or any power LED's?

 

[AllegroBarbaro]

I think it's unlikely the problem is your CPU unless it has bent pins or the cooler is not installed properly. Does the video card show any signs of life, fans spinning or any power LED's?

The CPU looks alright indeed, the pins look alright and I reinstalled the cooler today to be sure. The GPU fan moves just barely on startup, and the leds light up, so the gpu isn't dead. But I think the fan used to spin at max speed for a couple seconds on start-up, not like it does now.

Edit: in any case, if I connect only PSU and CPU and cooler, I don't get any beep-code. Is there any chance this doesn't imply that either psu, mobo or cpu are faulty?

Edit2: one morde piece of evidence for the CPU being healthy: if I add the ram, so that the mobo lights up and I get beep codes, I also observe that the CPU fan slows down after a couple seconds. If I am not mistaken, that means the BIOS are loaded and they take control of the fan, and that in turn means the CPU is working. Right?