So I wrote another post about a problem that now has turned out to be different, hence this new post.

The problem is on a T2 (wpc), the MPU board boots fine, but when I press on the upper/middle area of the board, it reboots or locks up (with the D19 and D21 solid lit which they should'nt).
If I press more, it wakes up again.
This sometimes happenes during play, without pressing on it (vibrations perhaps).

The same symptom can be seen with board removed from game and booted on bench.

The weirdest thing is that I can't locate where exactly to press - but seems that the upper area of the board (ribbons, cpu, rom) is most sensitive for the pressing.

So I am thinking that it must be some cold solder joint, I am resoldering suspected area but so far with no luck.

Is re-soldering the solution or could it be something else? All socketed chips are reseated and pressed firmly down.

Can I somehow locate which of the chips that is making this happen by using a logic probe (if it is a cold joint at a chip pin)? Like maybe follow the data/address lines from chip to chip beginning with the first chip to the last one, but maybe there isn't such an order for the chips?

Re-soldering everything seems really time consuming, and maybe even that won't help?

Here is a video showing what is going on!

I reflowed solder on most places yesterday, but it didn't help!

I barely touch the chips as u can see.

ANYONE, any ideas??!

Yes unfortunately really weird isn't it??

Thanks! So to be clear, it should be either a cold solder joint or a bad socket?
Is there a way to know if a socket is bad (bad tension and so on) by looking at it? Or test it somehow? I don't know otherwise what to do, cant change ALL sockets...

I really want to narrow down the issue rather than go bananas on all sockets and solder joints.

Thanks for all answers!

Either way, it seems nearly impossible to repair without being able to narrow it down to where the problem is.

I have a logic probe if that helps.

Should I give up?