7 replies to this topic

[chrishol]

This machine seems to function properly, (audio and game functions) other than no picture on CRT. The neck of the CRT glows, but does not seem to be getting any deflection, I have a dot in the center of screen, which I assume is the spot killer. I checked the power supply voltages and all appear normal according to schematic. Any ideas are appreciated.

Edited by chrishol, Sun Jul 3, 2011 6:43 PM.

[bennybingo]

This page helped me trouble shoot my Tempest monitor...I thought it was completely dead...ended up being a broken solder and a burnt fuse.

here is the article:

http://www.scribd.co...OTING-FLOWCHART

I hope it helps...maybe it's just a cap-kit needed or a fuse?

[chrishol]

Benny the references on the schematic refer to the monitor from a Tempest game, my monitor is an Atari quadrascan, chassis #G05802. The TO-3 transistors mounted on the frame of the chassis checked out OK. Any other ideas?

Edited by chrishol, Tue Jul 5, 2011 3:06 PM.

[Cassidy Nolen]

Monitors are notorious for cold solder joints. The fact you HAVE A spot is not too good. That means the spot killer is NOT responding correctly, leading me to believe you have a deflection issue as well as cold solder joints on the spot killer circuit. I would highly suggest finding your manual on that monitor and following the deflection cirucits through. Chances are you have to just reflow solder to the pins where the boards meet and you'll be attacking alien tanks in no time. Promise.

Cassidy

[chrishol]

I have no "Y" input signal into the monitor, which is causing the monitor to go into the spot killer mode. Using an oscilloscope, I lose the signal from IC E10 on the vector generator board which is part #LF13201, now I just have to locate one of these, anyone have a source for this part?

[Cassidy Nolen]

This help?

http://www.allxref.com/nsc/lf13201.htm

[chrishol]

I replaced the IC #LF13201 and the spot killer LED went out and the display returned, however when I pressed the "start" button, the display still reads "game over" the spot killer LED returns, display goes blank, then spot killer goes off and display returns. I scoped the X and Y vectors going to the monitor and lose both of them when the sppot killer momentarilly comes on. The game will not go through its normal sequence and the fire button has no effect. Any ideas?

[chrishol]

I performed the diagnostic self test and the screen shows a "4FF" not sure where this item is located, any help?