AppleColor High-Resolution RGB Monitor (M1297) Power Issue

[Qrani]

I have an M1297 to match my Macintosh II, and other than a slight bit of distortion at the top I've not really had problems with it. But recently, whenever I power it on, the monitor will come on for a second and then shut off. I hear the degauss sound, and the LED on the front comes off, but then go off. No picture on the CRT of course.

So I assume it's some problem with the power supply. The way it acts is like some sort of overcurrent protection. The past few times it did this, I would take it apart, unplug some wires, discharge the anode (it never is actually charged, because the CRT would only be on half a second), and when I would power it back on it'd magically work again. But now it doesn't. I made sure to take out the power supply. The fuses haven't been blown, none of the caps are leaking or bulging in any way. The board wasn't cracked, and I didn't see any solder joints that looked bad. I cleaned the board off. Nothing has fixed the problem, so at this point I'll probably try to recap the power supply, and while I'm at it I probably will recap the other boards as well (since there is a bit of distortion at the top)

But given that the caps look fine, I'm not sure that they are actually the issue causing this.

 

[robin-fo]

I was able to revive a M1212 with cracked solder joints and similar symptoms by simple reflowing. Are you really sure you inspected the solder joints carefully? Best reflow them anyway..

 

[-_- JC]

I have an M1297 to match my Macintosh II, and other than a slight bit of distortion at the top I've not really had problems with it. But recently, whenever I power it on, the monitor will come on for a second and then shut off. I hear the degauss sound, and the LED on the front comes off, but then go off. No picture on the CRT of course.

So I assume it's some problem with the power supply. The way it acts is like some sort of overcurrent protection. The past few times it did this, I would take it apart, unplug some wires, discharge the anode (it never is actually charged, because the CRT would only be on half a second), and when I would power it back on it'd magically work again. But now it doesn't. I made sure to take out the power supply. The fuses haven't been blown, none of the caps are leaking or bulging in any way. The board wasn't cracked, and I didn't see any solder joints that looked bad. I cleaned the board off. Nothing has fixed the problem, so at this point I'll probably try to recap the power supply, and while I'm at it I probably will recap the other boards as well (since there is a bit of distortion at the top)

But given that the caps look fine, I'm not sure that they are actually the issue causing this.

I'm having the exact same issue, as well as the distortion on the top. Did you ever fix the issue? I'd love to have mine in working order again.