yesterday I got this TI-99/4A in nice cosmetic condition.
It's a PAL version, 220V PSU. Modulator says VHF Channel 3.
I plugged it in an old TV I have and I just got a black screen with a continuous beeeeeeep tone.
I tried a different TV just in case and same problem. I've tried a cartridge (Parsec), with no luck.
I have a bunch of old computers, commodore, amiga, etc, but I never owned a TI before. I've read the sticky post for new members and it say that this symptom could be anything on the board.
I've already disassembled the machine, on a visual inspection everything looks good, I've re inserted the socketed chips.
PSU voltages are:
on pins 1-2 = 19.6V
on pins 2-4 = 9.15V
I see that these voltages are higher than specified on the PSU case, I guess it's because it's under no load?
What things should I check? I have no idea beyond this.
HERE is a video with the symptom.
Edited by zonaps2, Fri Oct 6, 2017 10:05 AM.