Tempest Troubles

Phetishboy

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I recently was having vertical collapse on my rebuilt 6100, so I decided that I would replace all 6 output transistors. Did so. Now the spot killer comes on and the game won't even play blind. I am getting EXACTLY 5V at the PCB test terminal, but both player 1 and 2 buttons are solidly lit, no blinking. The minute I hook the monitor up and turn it on, the spot killer comes on. When I power it up without the monitor hooked up, the LED on the board lights up and the game WILL NOT play blind. This game was working fine before the vertical collapse issue, and still played blind after the issue started. In fact, until I replaced the output transistors, it played blind. I really don't have time to keep screwing with this every weekend, and neither of my meters has a continuity tester. Can anyone help me figure out what might be wrong? I have an ARII rebuild kit and a new big blue, but I am tired of shotgunning. The transistor on the heat sink of the AR II is rustier than the color of Fritz's bearded clam. Could that be a problem? I restore these machines, and do my best to fix them when I can, but this one is frustrating and over my head. HELP.
 
My Tempest I just got locked up just like you are describing and it was BIG BLUE but did you check the bridge rectifier on the brick?
 
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The first thing you should do on ANY old Atari game is replace Big Blue.

The 2nd is to rebuild the AR board if the voltages are hosed... If they are OK then you should at least resolder the cracked connections on it.
 
Yea, check the ARII voltages first but also check them on the Tempest board at the testpoints to make sure you are getting a full voltage to the board. +5V is a good start but you might want to check the other testpoints as well to see if something pops up as wrong.

Sounds like you have 2 different problems happening at once. The monitor deflection transistors going out can't cause the game to not play blind unless there is a big short causing a huge current draw through the vector generator. But I think you would blow fuses on the deflection board before that happened.

One more thing, if you have pulled the main boardstack out at all, push down on all the socketed chips to see if that gets you back to playing blind. Tempest is terrible with connections. Also make sure you didn't accidentally flip the game to test mode either with the dips or the switch in the coin door.
 
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Note that if the power to the board isn't good, that can cause the X/Y outputs to be incorrect, which can easily be confused with a monitor deflection problem. I hope you didn't throw away the transistors you replaced, there may well be nothing wrong with them.

If it's not a power issue you might have issues with the edge connector for the PCB. I seem to always end up replacing them sooner or later, and the process often turns a flaky temperamental game into a rock-solid one.
 
Here's what's been done:

-Bought the game working
-Was told that the 6100 should be rebuilt and LV kit added to make sure it didn't go bad later, taking out chips on the CPU. Sent monitor chassis HV cage, etc to a reputable Vector repairman
-Got the parts back, had Chris25810 put the monitor back together at my place before my party, asked if we should replace the transistors, told if they worked before dis-assembly, don't bother.
-Got it back together, but the spot killer came on. Let it sit.
-Replaced the larger edge connector to the CPU. Game fired up and ran for 2 months
-played it one night, left it on about 2-3 hours, found the image had bloomed/expanded/ballooned off of either side of the screen. Began messing with the X/Y pots on the CPU. Got it closer, but still way too big.
-turned it on the next morning, had a vertical line down the center of the screen, game played blind
-removed 6100, replaced all 6 frame mount transistors, resoldered one broken wire back to it's transistor tab. now spot killer comes on and plyr 1&2 buttons solidly lit.
-Cried, asked for help, then began drinking heavily and tried to forget about it.
 
Well I like that you have been watching the player 1 & 2 start buttons to see if they are flashing or not. You mentioned that they are "solidly lit" not blinking as normal. Sounds like the game is either in a constant reset mode, or pause (which is a dip switch setting).
The reason I pointed out pushing in on the chips is just 3 days ago mine was working fine when I turned it on and then I glanced back at the screen and it was black. This didn't make sense as I have upgraded everything that normally flakes out over the 6 years I have owned it. It sits in an air conditioned room and hasn't been moved. I pulled the board out and one of the ROMs gave a little when I was pushing on all the chips, put the boardset back in and it came on again. That's just how it is.

This is the way I would do it: try and split the problem in half (not trying to insult your intelligence if you already know this)
1.monitor or board (in your case both)
2. go after fixing the board first since even if the monitor is working you might not know it until the board is working
3. at the board is it power or logic
4. check all voltages, if you have correct voltage on all test points then move onto logic
5. check X and Y outputs with oscilloscope
6. Check 6 Mhz clock testpoint with oscilloscope
7. Check the watchdog with oscilloscope

The last 3 I didn't go into detail as I am not sure how technical you want to get with this.
 
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Well I like that you have been watching the player 1 & 2 start buttons to see if they are flashing or not. You mentioned that they are "solidly lit" not blinking as normal. Sounds like the game is either in a constant reset mode, or pause (which is a dip switch setting).
The reason I pointed out pushing in on the chips is just 3 days ago mine was working fine when I turned it on and then I glanced back at the screen and it was black. This didn't make sense as I have upgraded everything that normally flakes out over the 6 years I have owned it. It sits in an air conditioned room and hasn't been moved. I pulled the board out and one of the ROMs gave a little when I was pushing on all the chips, put the boardset back in and it came on again. That's just how it is.

Reset button. Hmmmm, that seems to be pushed all the way in and pushing on it does nothing, like it won't pop back out. I did push that button a few times when I was messing with the X/Y output pots. Wonder if it's stuck closed?
 
Reset button. Hmmmm, that seems to be pushed all the way in and pushing on it does nothing, like it won't pop back out. I did push that button a few times when I was messing with the X/Y output pots. Wonder if it's stuck closed?

That little flat grey thing... yea it's hard to tell if it's moving when you press on it. I haven't seen one yet that was stuck closed, but you could check it. Usually a stuck reset is more in the logic circuit, like a failing flip-flop or gate IC.

Another non-tech trick you could try is leave it on (monitor unplugged) and feel the IC's to see if one is getting really hot.
 
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