R60 mobo working only after short warm up with hot air

[PJs]

I've got 3 motherboards (2x R60 Intel, 1x Z60m ATi X600) with the same problem right now. All fuses are OK and all 3 motherboards don't have any signs of spill damage, or burned components. The problem is, they seems to be completely dead - no LED flashing or any response on power-on button. Doesn't matter if I'll try to turn it on with battery or adapter. But what is curious - when I'll take a hot air on my soldering station and warm up whole motherboard on about 70°C, they will (all 3) start working and they are running without any problems for some time. Few days after this "resurrection", the problem is back again.

Is here anybody who have any ideas what's wrong with it?

Many thanks!

(I'm sorry for my poor English:))

[sb102]

Welcome to the forum,

Well, it looks like there isn't enough solder on some component (my guess is that it's connected with the components of the power sub-system) - in that case flex applied on the motherboard or heat generated by the laptop itself can cause those symptoms. If you want to fix it, than you will have to localize the faulty solderings and fix them (if it's a SMD bit, than apply more solder, if it's a BGA chip - reball it). That would be the explanation of the problem judging by your post.