Tempest - Spot Killer on - Monitor good - Board not displaying output

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Tempest - Spot Killer on - Monitor good - Board not displaying output

Working on a Tempest. The board plays blind. I repaired the monitor and all is good there.
I swapped in a good working board and the monitor is perfect. Something is going on with
the board now giving me the spot killer. I pulled and reseated all socketed IC's with no change. Anyone know what I should be checking? there is zero pic. I could hear the game play fine.
 
it's a bunch of chips in the analog section (the silver part of the board). if the XY outputs are too high, it's supposed to shut the monitor down in spotkiller. the Tempest I have has the add-on board on the 6100 that's supposed to protect the frame transistors from that.

I need an entire set of the chips for another board I pieced together, but none of the vector people want to answer my PMs, and I can't do it myself because I can't source the chips on my own.

but hey, I'm sure andrewb will be here to answer you soon.
 
it's a bunch of chips in the analog section (the silver part of the board). if the XY outputs are too high, it's supposed to shut the monitor down in spotkiller. the Tempest I have has the add-on board on the 6100 that's supposed to protect the frame transistors from that.

I need an entire set of the chips for another board I pieced together, but none of the vector people want to answer my PMs, and I can't do it myself because I can't source the chips on my own.

but hey, I'm sure andrewb will be here to answer you soon.

Yes.. I had a feeling. Maybe Andrew can direct me better on what I'm supposed to be looking at here.
 
There are voltage test points in the analog (silver quadrant) of the PCB. Check for proper +15v, -15v, and +6.8v... all DC voltages.

Also check for Ac and DC voltage at the X out and Y out test points. You should have very little (<1v) DC and around 3-4v AC at each of them.

If you have a scope, hook it up to the X and Y outputs and see what (if anything) is being drawn.

If not, but you do have a logic probe, check pins 2 through 11 of the main DACs at A10 and F10. If they are not pulsing then you have a logic (pre-DAC) problem. If they are pulsing then you probably have an analog (post-DAC) problem, such as a dead op amp (TL082) or switch (LF13201).
 
There are voltage test points in the analog (silver quadrant) of the PCB. Check for proper +15v, -15v, and +6.8v... all DC voltages.

Also check for Ac and DC voltage at the X out and Y out test points. You should have very little (<1v) DC and around 3-4v AC at each of them.

If you have a scope, hook it up to the X and Y outputs and see what (if anything) is being drawn.

If not, but you do have a logic probe, check pins 2 through 11 of the main DACs at A10 and F10. If they are not pulsing then you have a logic (pre-DAC) problem. If they are pulsing then you probably have an analog (post-DAC) problem, such as a dead op amp (TL082) or switch (LF13201).

good to know. I know the stuff is bad on that one, I'm getting about 10V DC if I recall.
 
There are voltage test points in the analog (silver quadrant) of the PCB. Check for proper +15v, -15v, and +6.8v... all DC voltages.

Also check for Ac and DC voltage at the X out and Y out test points. You should have very little (<1v) DC and around 3-4v AC at each of them.

If you have a scope, hook it up to the X and Y outputs and see what (if anything) is being drawn.

If not, but you do have a logic probe, check pins 2 through 11 of the main DACs at A10 and F10. If they are not pulsing then you have a logic (pre-DAC) problem. If they are pulsing then you probably have an analog (post-DAC) problem, such as a dead op amp (TL082) or switch (LF13201).

Thanks Doug, I'll check tonight.
 
update

I'm onto something here now. I have a missing vertical 10k pot at R150 X Size. Could this be
why I'm not getting any picture?
 
I'm onto something here now. I have a missing vertical 10k pot at R150 X Size. Could this be why I'm not getting any picture?

Yes. And the MC1495 at C12 may have been damaged by running without it but without a scope you'll need to go one step at a time.
 
There are voltage test points in the analog (silver quadrant) of the PCB. Check for proper +15v, -15v, and +6.8v... all DC voltages.

Also check for Ac and DC voltage at the X out and Y out test points. You should have very little (<1v) DC and around 3-4v AC at each of them.

If you have a scope, hook it up to the X and Y outputs and see what (if anything) is being drawn.

If not, but you do have a logic probe, check pins 2 through 11 of the main DACs at A10 and F10. If they are not pulsing then you have a logic (pre-DAC) problem. If they are pulsing then you probably have an analog (post-DAC) problem, such as a dead op amp (TL082) or switch (LF13201).

Ok.. So here's an upate. I installed the 10k trim pot at R150 and still no picture. Game plays blind and spot killer comes on. So, I checked 15vdc, -15vdc, and 6.8vdc - These are spot on. Now for the X output DC I get 10.2vdc and the Y output gives me -8.2vdc. Something wrong here perhaps?
 
Ok.. So here's an upate. I installed the 10k trim pot at R150 and still no picture. Game plays blind and spot killer comes on. So, I checked 15vdc, -15vdc, and 6.8vdc - These are spot on. Now for the X output DC I get 10.2vdc and the Y output gives me -8.2vdc. Something wrong here perhaps?


Yes that much DC voltage will fry things on the monitor. Unplug it. Use a logic probe to check the input pins 2-11 on each of the 6012 DACs to see if there is activity.
 
spot killer

Hello,
had an issue a while ago with the spot killer, it turned out to be big blue a lot of ac not being filtered
 
Thanks for the reply but I'm having the same issue as the person who started the post. I have two board sets, one works fine and the other causes the monitor to go into spot killer. Unless the one good board is so good it can overcome power supply issues, I'd guess it's the one board set that's having issues.
 
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