Master System (SMS) PCB issue

[Niku-Sama]

I haven't been able to sleep and so I started poking around while I think about how I am going to go about my SNES mod. I decided to work on my SMS.

its never worked, I picked it up at PRGE last year as part of a $5 a bag thing at one of the vendors. it would show random colored screens but never boot.

it started out ok. tested the voltages, then some smoke came out of it, poked around, replaced a cap that I thought was the problem, it wasn't, tested it and it booted to the put a cart in and enjoy screen.
GREAT. got it all back together, wont work. tear it apart, I start tapping chips checking for a loose connection. it seemed to work when I flipped it upside down for some reason. I reflowed the Z80 and a few other ICs, seemed to boot more often but not always. removed the pause and reset buttons since they didn't seem to work but no change. some where in all that I repaired a broken trace at the cap right next to the pause button, but it wasn't any different. it was broken broken, the cap was still attached to the trace but the trace was peeling off. carefuly removed the cap, flattened the trace, scraped away some of the mask and bridged it. it was to ground.

after reflowing since it seemed better I held it up to the light to see if I could see any light coming through next to any component legs and I noticed that theres a crack radiating out from the center most screw hole.
bring it in, press a little on the screw hole and turn it on, boots, when I let go it freezes.

is this a common problem with these?
this system is only 1 of 2 I have ever found "in the wild" the second some one was trying to sell for $85 by it self no games or controllers at a pawn shop. i'd like to fix it
if I were to fix it what way would be easiest? I did scrape away the mask on a lone broken trace and bridge it with solder but some of these are really close together. the crack only goes through one on the bottom.
each affected trace has 2 vias, one on each side of the crack. the vias have that blueish sealer over it though

i'm also not sure if I should screw it in using the center screw any more if I want it to last

[jb143]

I was going to suggest re-flowing all the solder joints and checking the traces for breaks but it sounds like you already did that. If any of the traces seem suspect you can solder jumper wires. It sounds like it's more of just old PCB problems than a SMS specific issue to me(though using low quality caps or something wouldn't have helped). In a box in the attic is what I see a lot as the fate of old game systems. Storing electronics in a shed or attic where it will get really hot in the summer then really cold in the winter is a sure way to speed up component failure.

[Bratwurst]

30 AWG kynar wire is probably what you want to use to bridge those broken traces and keep everything thin if they're close together.

[Niku-Sama]

I don't know what gage wire it is but i usually strip an Ethernet cable and use the conductors inside as jumpers.

Cheap easy and i have 300 feet of it

[Bratwurst]

Ethernet wire is usually 22 or 24 AWG, I'm sure it would do the job, I just recommended the kynar wire in case your traces were really fine.

[Guntz]

Solid core IDE cabling works good too, just chop off the IDC ends and peel off what you need.

[APE992]

Sounds like overtightening. The PCB is pretty robust overall but traces aren't that hard to break.

[Niku-Sama]

true but it did this to begin with and it seems as if it had never been opened before.

the center mount for it is also not re enforced/grounded like most would be and judging on how its cracked I imagine it was expanding and contracting over time that may have done it.
PCBs are generally pretty durable but occasionally I come across a really brittle one