PC turns on, but no POST.

[cess_cabs]

Hello. I have a pre-built 2015 HP ProDesk.

 

Just this morning I was still using it perfectly fine and then I turned it off to do some errands. Later that afternoon, I went back to my room and turned my computer on again but then it didn't turn on and flashed a 5.2 error beep code.

 

I went to the HP Forum to follow their guide regarding basic troubleshooting of these beep codes. I followed their listed solutions. I plugged it off, opened it, and reset my CMOS battery. It wasn't on the listed solutions, but I also took the liberty of re-seating the RAM because when I had minor problems with the PC, I usually just reseat ram and disconnect-connect some cables and it goes back up again. 

 

After that, I turned on the PC. The beep code was gone, but now it was just powered on with the HDD lights not turning on or even just blinking. The fans are up and running, my mouse didn't light up, but my keyboard actually did.

 

Got back at it again. I tried to power it off by holding down the power button, but it won't power off that way, so I just unplugged it from the socket. 

 

I opened the PC again, disconnected some cables and took out the RAM, then I took out the CMOS battery to reset it (it doesn't have the jumper, just manually taking out the battery is the way). Gave it a good 30 minutes, and put everything back properly. I turned it on, and it was the same powered on but no POST state.

 

I disconnected stuff again, but now I cleaned off the surface of the motherboard and the fans (didn't take out the CPU and heatsink) because I thought maybe it may help somehow. Gave it a good hour this time. I put everything back again, but still to no avail. Did it a couple more times, still the same powered on no POST.

 

I have checked every cable, making sure they're seated and connected properly. Also checked the capacitors, no bulging, leak, or any damage of any sort. I have reseated the RAM several times. I have also replaced the PSU with a spare PSU I have that I am very much sure is 100% working. I've tried it another couple of times with my current PSU and the spare (both 100% fine), but still powered on but no POST state.

 

What could be wrong? Thank you in advance. I have a lot of work piled up because of this :((((((

 

[bellabichon]

Try yanking out the hard drive, and see if you can get into BIOS then. Whenever a PC powers off and doesn't power on, my first guess is gonna be that the hard drive went poof. 

[cess_cabs]

5 hours ago, bellabichon said:

Try yanking out the hard drive, and see if you can get into BIOS then. Whenever a PC powers off and doesn't power on, my first guess is gonna be that the hard drive went poof. 

Hi. I tried that now. I took out the drive, held down Win key + B and turned the PC on without it, but I wasn't able to reach the BIOS and still wasn't able to POST.