Hello guys! This is my first post and English is not my first language, so please forgive any mistakes.
So a few days ago I found this little guy in a storage room filled with broken pcbs and other junk and i decided to try and fix it.
First i noticed that the top part of the power switch was missing so i closed the circuit by putting jumpers on the switch,
then plugged in a 9v adapter and tried hooking it up to a CRT to see if it was working...nothing came up so the first thing i checked was the 7805 regulator which was dead.
I replaced the 7805 and i made a rough RF to AV mod (just video. no sound) from a schematic i found online. I plugged it in (AV) and this time it worked perfectly, even when i connected it through RF,
it had a bunch of built in games on it, it was great! But sadly after 10 minutes or so, the picture went crazy all of a sudden with flashing colors of all kinds of patterns (see attached photos).
Also when i plug it to the RF connector the picture is blue-ish with static and there is a high piched sound in the background.
I really hope i didn't fry it or something, because i wanted to make a case for it and give it to my brother as a birthday present...
Any ideas what's wrong with it, or how to troubleshoot it? I'm not really good on electronics but i know a thing or two...
I also attached the AV mod i i did (not my photo).
Thanks in advance!