This was a custom-built job completed at the end of last year. It had been working absolutely fine, booted up with no probs at all at least three times already today. No internal changes. The only change made was to plug a dvi-vga cable into the extra monitor-out slot on my gfx card. After that, nothing. Ka-putsville. The fans start. The power led comes on, but that's it. No hard-drive light comes on. No beeps. No bios screen. No activity. Nada.
Nothing happens. It doesn't post, doesn't boot.
What i've tried: No brainer - opened the sucker up, checked connections on hd, mobo, etc. Seems fine.
Took the ram chips out. Put one back in on it's own. No improvement. Put the other one back. Still no change. Interestingly, i took BOTH out and tried switching it on with no ram in at all, and got exactly the same outcome as before. Hmm . . .
Also, i've noticed that it powers up as soon as it is switched on at the plug. Before, you had to switch it on using the power button on the front of the case. Not so any more.
I'm not sure whether that's a clue or not.
The case was the cheapest bit of the whole build, but i have no idea whether a glitch with a measly little power button could cause this specific set of symptoms.
Moreover, i don't have a spare psu, mobo, ram chips, cpu, or case to use to conduct further experiments. As i understand it, the problem could lie with any or all of these seperate components, so to start buying replacements without any clear idea beforehand which one is faulty is going to be tantamount to starting a new build from scratch. I figure it'll work out cheaper to take it into to a shop to have a boffin look at it . . . unless anyone here has any better ideas.
Thanks in advance for any and all replies.