Coleco Telstar Marksman - Light Gun

[Trent555]

Hi, Im not sure where to post this so I’ll try here.

 

I recently picked up a Coleco Telstar Marksman in super condition. The unit powers up and all the buttons (Select game and Reset) and pong knobs are responsive.

 

My problem herein is with the light gun. Whenever I plug the light gun into the telstar unit, and then turn on the power, the unit crashes into a snowy-static screen on the tv. If I remove the gun, the pong games come back to life on the screen. I checked all the male-prongs of the light gun plug with that of the circuit inside the gun and the continuity checks fine (I was checking for broken wires and broken pcb traces).

 

The inside of the Telstar unit look fine.

 

I’m baffled as to why plugging the light gun into the system and powering on, causes the system to crash to a snowy static screen on the tv. If any Telstar collectors know of the problem or areas I can further check, please post to this in the forum.

[chas10e]

you using batteries or an AC power supply ?

 

I wonder if power draw from the gun might be over taxing some weak batteries

[Trent555]

I was using the Telstar AC Adapter....no batteries.

[Osgeld]

well something is drawing too much power to cause the machine to puke out, could be the supply could be the gun could be both

[bah]

did you check pin to pin on the gun for a short? I don't know anything about the system but if a power lead to the gun is shorted it would draw more power from the unit.