The all-in-one pc does not power up

[Reef2005]

The all-in-one pc does not power up. I tried the usual checks, all seems fine but no success. When the adapter cable is connected a small light comes on at the back of the pc just above where the cable is connected. Unfortunately we're in Corona lockdown and I can't take it to a repairer. Has a similar issue been resolved?  

[Reef2005 · Accepted solution]

I'm glad to say problem solved. The logic that I followed was to trace the cables and connectors from the power button and see if something can be changed or replaced.

. I removed the cover from the back of the pc

. In the case of touchsmart 520, the unit is almost militarily built and protected in solid aluminium. I could not find where the power button cables go without dismantling the whole unit. I was not keen on this since my pc hardware knowledge is limited. I expected the motherboard to be visible without too much fiddling but it was not.

. after some random exploring without a result I thought at least I can remove the hard disk and access my files.
. with the conclusion that this needs a professional repairer I began to put the screws and cover back on when I noticed a small 3inx3in metallic 'cage' which when (easily) removed showed the area where memory modules are installed. 

. looking closely inside I noticed there was a circular battery approx 1in in diameter in a metallic casing just on the left of where memory was installed - see attached pics. I thought it strange that the manufacture would put a battery of this type inside the unit given that batteries have to be replaced even if they are rechargeable. So the logic is that perhaps this battery is dead.
. So I replaced the battery (duralex 2032), connected the mains cable then pressed the power button and lo and behold ... the pc starts up and is alive and well. I hope this helps someone else in the same situation: