Recent content by lostone

Can anyone confirm the transformer outputs are basically just two at 5V each? I've done everything except start feeding the inputs to confirm and all I find appears to be two coils or one coil with wired to 5 pins. I wasn't able to see how the voltage feeding the 5V line is negative since pin3...

One of several nice things about the Astec AA16-251 version of this supply (which also needed a restore after the two 120uF caps C17 and C20 were found to have 0 capactiance) is the wires are soldered directly into the board with silkscreens! Orange: +5, Yellow: +12, and Blue: -5. This is also...

@ben68k since you're actively digging around in the circuit, could you do me a favor and check the voltages on the C78N05 (IC51). I can't figure out the input voltage (pin1), (with pins numbers 1, 2. 3 when looking at the label side). As noted a couple posts early I am unsure questions about the...

Has anyone found a modern equivalent of the C78N05 (IC51)? I've got the unstable -5V output after recapping (and looks like there may be electrolyte or something else on the board, cleaning has been in progress next would be depop and clean or ultrasonic. But before doing that I started looking...

Did anyone with the unstable -5V condition get things resolved? It looks like RetroViator found a unrelated fix. I'm with chuck42 unloaded goes all over while +12 and +5 are rock solid. I've cleaned the board several times, but didn't depopulate the entire board which may be needed. I saw the...