Opening cabinet makes PC unbootable

[Cool Buddy]

I'd been thinking of asking this for a long time. Last 2-3 times when I've opened my cabinet for cleaning, it refuses to boot up after I put it back in order. First time I had opened the RAM, but the second time I hadn't opened anything on the mobo, just the cabinet cover. I used a soft brush to clean the surface and then blew away the dust. Later when I switched it on, it refused to boot up. although the power LED did light up, there was no display. I had to hold the power button to shut it down again. Then I made the cabinet lie down on the side and then it switched on.

What could be the problem. once it starts, there are no other problems. I guessed it was a loose wire somewhere.

[Ponmayilal]

Looks like a loose connection somewhere.

Next time you open up the cabinet for cleaning, before the final close up, make sure to keep your PC in its normal upright position and press all the cable connectors lightly to ensure they are firm in their sockets. This may perhaps resolve your problem.

[asingh]

^^
Is it an OEM system, or self assembled. Sometimes cabinet+motherboard combination have Intrusion Alert system, which disables the booting, if the side panel is removed. My board has it, but I keep it disabled.

[Cool Buddy]

It is a self assembled one. It has no such system as I have seen it booting with an open cabinet. The problem started after I had to replace my motherboard (the previous one got damaged, replaced under warranty) and replugged the CPU on it. But after that, I have never touched the CPU again

[asingh]

^^
Just re-do all the wiring what else. Check that the HSF is firmly mounted..!

[Cool Buddy]

OK, I opened my cabinet yesterday for cleaning & found out the reason. After I rebooted it, as expected it didn't boot up. So I entered the BIOS setup. there both SATA1 & SATA2 were being shown as not detected, so basically it was not detecting my HDD. I put the cable on the 2nd slot on the mobo, didn't help. I changed the cable didn't help. I left the PC idle for 10 minutes, voila, it booted up. So basically my HDD's sata connector is not working properly I suppose.

[asingh]

^^
Seems so they are failing. Or try different HDD / sata connectors.

[Cool Buddy]

I tried both conenctors on the mobo & tried a brand new SATA cable too. None of them solved the problem, the problem is definitely with the HDD as it has started over heating too. I hope it fails completely during the warranty period itself.

[asingh]

^^
Take a backup. Run a HD Tune error check on the drive volume..?

[Cool Buddy]

Yes, I was also thinking of it, but I didn't know which software to use. Thanks for the suggestion

[g160689]

from hardware guy i get to know most of the time its ram problem. There is a little chance that the processor is misplaced. and comp can start without hdd. But without proper fit of ram in pin sockets, comp wont start. Just a light push in the socket, not too hard not to easy, makes it fit better.
Once i have also experienced exactly same.

[Cool Buddy]

Yes, the computer is starting, it's not that it isn't. But since there is no HDD, there is no SO. I can enter the BIOS when it boots up. That's how I got to know that it isn't detecting the HDD.