Tempest monitor help

flyarlee

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Hey I just bought an Atari tempest and I'm getting a weird monitor problem.
I switched out Another working PCB and I got the same problem so I'm pretty sure it's not the PCB. The same problem happens no matter which PCB I use.

When I boot up the picture is crystal clear.
Shortly afterwords the picture becomes unstable and gets smaller and smaller until it dissapers and shuts off completely. The spot Killer willl then turn on.
I wait awhile and it turns on again.

Any thoughts on what's going on?


Thanks
 

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You need to watch blkdog7 latest utube vids regarding his Tempest. Same / similar issue.

He rebuild the entire monitor but in the end it was the neck board. Surprising as I would have thought it to be the HV cage (pot or flyback etc).

Fascinating.
 
Could be a deflection board problem. Spot killer will turn on any time there is no current in the yoke. So that means either the game board is screwing up, or the deflection output is failing.
 
I was thinking it might be something in the neck board. The big white ceramic (resistor?) at R528 on the neckboad was super hot after a few seconds after the monitor shut down.. thanks for the videos I'll keep watching.
 

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Well I re-flowed everything and made sure I had good continuity betweeen pins and I did. I then plugged everything back in and the spot killer was on From the get go with no picture..I then heard a loud pop and shut things down. No arcs on the board but I blew the 3A fuse at f700. Any ideas what to check now?
Thanks!
 
well, like i said. deflection board issues. If this issue persisted between two boards then likely the deflection amplifiers are bad. Before you order anything, check to see if all 6 frame transistors are good, especially since you blew a fuse.
 
Thanks Ian!
I'm not sure how to test the 6 frame transistors, any good links to point me in the right direction?
Thanks!
 
well to put it bluntly. just put a multimeter on continuity test and check if there is a short between a pin and pin, a pin and the cap. So pin->pin, then Pin 1->body, Pin2->body. That's a good enough test for this issue.

It is always best to remove the transistor from the monitor before testing.
 
well to put it bluntly. just put a multimeter on continuity test and check if there is a short between a pin and pin, a pin and the cap. So pin->pin, then Pin 1->body, Pin2->body. That's a good enough test for this issue.

It is always best to remove the transistor from the monitor before testing.

So I removed the boards and tested the transistors while they were in the Frame. If I need to remove them first I can do that too but in that case it might just be easier to buy new ones to install anyway?

So, I did not get any shorts at all when I touched the ends of each pin and then each pin to the frame for all six transistors.

Any ideas on what to test/try next?

Thanks!
 
Okay super weird now!
Thoughts on my tempest? I just replaced 3 shorted frame Resistors, with good ones that aren't shorted. At first when I turn the game on I get the spot killer and nothing on the screen. A pulsing buzz can be heard somewhere in the chassiss/tube/high voltage area.
Then after a few minutes the spot killer pulses with the buzz..and the monitor turns on and off with the buzz...

I have a good working tempest and it does this even if I swap the pcbs out.


Any ideas what to check next?
 
Okay super weird now!
Thoughts on my tempest? I just replaced 3 shorted frame Resistors, with good ones that aren't shorted. At first when I turn the game on I get the spot killer and nothing on the screen. A pulsing buzz can be heard somewhere in the chassiss/tube/high voltage area.
Then after a few minutes the spot killer pulses with the buzz..and the monitor turns on and off with the buzz...

I have a good working tempest and it does this even if I swap the pcbs out.


Any ideas what to check next?

To confirm, you get a picture after a few minutes, but it goes in and out? If that happens on multiple boards, then it could still be several things ranging from the wiring harness edge connection all the way back to the monitor. My first thought was cold solder if the game improves after warming up.

Scott C.
 
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