"alex goldman" schreef in bericht
...
wrote:

Physically broken/cracked surface mount components or the solder
connections to same. Rarely visible to the naked eye.

Is it practical to try to diagnose it further, and if so, how?

I won't bother with the phone (it's cheap), but for the laptop I couldn't
locate a replacement motherboard, and getting a completely new one is
expensive.

Is it possible to fix a motherboard if it has such problems somewhere
(broken/cracked surface mount components or the solder connections to
same)? If so, what kind of equipment, knowledge and time commitment will I
need?

In the days that PCBs were expensive, so you could take an hour or more to
pinpoint the fault, our techs used an hair dryer and a can of coolant. Of
course, experience was the other half of the requirements. The latter faded
away when the repairtime/board shrinked. I still own a working XT of which
the motherboard was rejected as the fault could not be located within half
an hour. I got it for a small contribution and made a running machine in one
evening. These days PCB repairs are rare, very rare. That's to say for
professional/commercial use. Even boardswapping becomes too expensive in
some cases. It has been six years now I bought a monitor. Within warranty
time it was swapped as a whole. After three years, when warranty was over,
it was said to be unrepairable and I was advised to buy a new one. To make a
long story even longer: Cans of coolant are still available but I'd use a
hot air soldering "iron" for the hot part. Components became very small you
know. Besides, you'll need lots of time and even more lots of luck.
Nevertheless it may be worthwile to give it a try. Good luck.

petrus bitbyter