ok, so I'm quite confused as to what's going on with my HTPC and wondered if anyone here would have thoughts or suggestions that would prove useful.

History - new build HTPC about 6 weeks ago - has been up and running perfectly all that time in my kitchen where I put it together.  Came home from holiday and decided to, finally, move it to the TV room so powered down, unplugged and walked all of 3m.

Put it in place, cabled it up, powered up and nothing much happened at all.  System and case fans spin up when you press the power button and, after a few seconds, power down again before starting a start/stop loop that seems indefinite.

Have tried the usual things - unplugging all components, removing and reseating ram but am at a loss as to what else could be wrong (other than the mobo/cpu or psu), even though I can't see how simply moving them from one room to another could break something (assuming the worst).

So, any thoughts, tips or tricks I could try to get it working again without spending a fortune?  or being without it for however long it takes retailers to receive returns, test and return/ship replacements as appropriate?

Slightly bemused, seriously annoyed.
 

Sounds like it could be numerous things. 

I would try removing one component at a time and see if anything changes.
I would start with the CPU cable from the PSU...sounds like that one got loose. Than see if everything else is attached to the motherboard.
If that is not the case, than your psu might be head. Try the paperclip test (google it).

 

here are my 2 cents / penny of thoughts and PURE OPINION which works for me.. well  my ANCIENT SET of desktops / abandoware workstations... 1 is good old faithfull pentium 3 500 MHz and the other is pentium Core 2 duo tower. Both systems are as of current in a sort of dust proof vacuum bed cryo state only activated when needed but both are on their last life support spare part mother boards whose RAM slots get loose and they need to be re plugged in for system to properly boot ... but your system , from your post is new and i am frankly unaware of this brand .. so best bet is to disassemble and reassemble the system from a system expert if its branded or DIY i guess.

Peace

I had my PC die 2 days ago after a reboot.  Pulled the video cards, put 'em back in, fired back up no problem.

My youngest walked downstairs, into the server room, and pushed all of the buttons on the UPS stack.  Killed 2 mobos that had been on for damn near 5 years. :P

The pricing is amazing.  When I bought those 2 servers, they were about $600ea.  The replacments were an entire generation newer (3.0ghz vs 2.5ghz in the old boxes) and were only $150ea. :P

i have a 5 years old pc i only changed the cpu fan cuz was so loud and i only paid about 15 dollars for a very good one i was wondering to buy a noctua-15-16 and i can play games like this new ones gta 5 or just cause 3-4 
i remember that my pc had one problem when i was replacing the fan with the hdd i forgot that i unplugged it and wasn`t detecting my hdd for starting the windows i reassambled the pc 4 times before i saw the problem :)