1975 RCA XL100 model CU 680 W trips reset button when turned on

[pac.attack76]

Red reset button trips when power knob is pulled out. Reset and does it again. Where should I begin looking? Interested in fixing up and using with Atari games.

[damen]

Remove the power supply diode board, reset the breaker and see if it holds and the channel light comes on. If it does, check all nine diodes on the little board. If diodes all check good then there's a short on one of the B+ supplies. Large filter cans, vertical or horizontal SCR issues were common. Can remove the SCR mounting screws to check them without actually having to pull them out of their sockets.

[pac.attack76]

Originally Posted by damen

Remove the power supply diode board, reset the breaker and see if it holds and the channel light comes on. If it does, check all nine diodes on the little board. If diodes all check good then there's a short on one of the B+ supplies. Large filter cans, vertical or horizontal SCR issues were common. Can remove the SCR mounting screws to check them without actually having to pull them out of their sockets.

Sounds good, I'll check it out soon as I can get around in here. I've got stuff scattered everywhere.

[JohnCT]

Originally Posted by pac.attack76

Sounds good, I'll check it out soon as I can get around in here. I've got stuff scattered everywhere.

If you find a shorted diode, change the other three in the same bridge grouping. I believe there are two full wave bridges on that small card, plus another diode that never shorts.

Those are standard recovery diodes, so any typical rectifier like the ECG 125 will work fine.

John

[pac.attack76]

Great, ty🙂

[pac.attack76]

Restoration begun on this set. I've managed to get the entire outside done. Now if I can ever get inside and begin with repairs.

[JohnCT]

Is that the model with those miserable little sliders behind the door?

John

[dishdude]

Cabinet looks great.

[pac.attack76]

Thank you. Yeah it has the 4:sliders for contrast, etc.

[JohnCT]

Originally Posted by pac.attack76

Thank you. Yeah it has the 4:sliders for contrast, etc.

The controls are usually good, but those little chromed plastic sliders like to break. If you have to adjust them, try to push them at the base of the slider instead of using your fingertip at the top of the slider. Takes the torque off them.

I used to buy them 50 at a shot back in the day.


John

[pac.attack76]

These are still intact and move without a problem. I'll still watch out for them. Can't wait to get this up and running. I plan on using Atari games on it.

[consoleguy67]

Very nice set.

[pac.attack76]

Originally Posted by consoleguy67

Very nice set.

Ty🙂

[Rog Beltmann]

If power supply checks ok don't overlook the trace/retrace SCRs

[pac.attack76]

Ok👌