Dead Tempest

zenomorp

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Never worked on a Tempest before. The monitor has glow, but the LED on the main PCB is off. The MCR(?) board has 23vdc on one side but the 5vdc side is dead. Can I just install a switching supply for the board? What is the 23vdc side used for? The manual doesn't have any wiring schematics or drawings. Thanks.
 
Never worked on a Tempest before. The monitor has glow, but the LED on the main PCB is off. The MCR(?) board has 23vdc on one side but the 5vdc side is dead. Can I just install a switching supply for the board? What is the 23vdc side used for? The manual doesn't have any wiring schematics or drawings. Thanks.

Could be a fuse in your power brick on the floor, or something wrong on the AR-II board. I think what your calling the MCR, is the PCB stack to the right of the cabinet? You will want to check the smaller 6"x12" board straight ahead which is the AR-II board.

I live reasonably close, so if you get stuck I might be able to stop by and check it out.
 
Test your voltages on the AR-II first. You should have 12-14VDC on the 10.3V test point, and 5V on the + side of C1. It sounds like you have +/-23V on the right side, which are used for the video section of the game board, which generates the XY voltages for the monitor.

If you are missing the 10.3V, you have an issue with your power brick (either a bad bridge rectifier, and/or bad big blue cap, and check all of the fuses).

If you have 10.3V but no 5V, you have an issue with the AR. Look to see if R29 and/or R30 are burnt. If so, you have an issue with your edge connector (which is either dirty, and/or the pins are stretched out and are not making contact with the fingers on the PCB). You can clean the edge connector, repair the pins, and replace the R29 and R30 (both 10 ohms, 1/4 watt).

If the resistors are ok, replace the 2N3055 on the AR. That should get you 5V again. But without 5V, nothing will run, which is why there is no 5V LED lit on the game board.

There is also no need to use a switcher in these, and it's not really straightforward to do anyway, as the AR also provides the audio amplification, so ditching the AR requires separate audio amps. It's just easier to fix the original supply, which is not that hard, and they are perfectly good systems when properly repaired. I can walk you through it, if the above doesn't work.

Be aware you may have other issues, but for any vector game, you want to attack the problem in stages, verifying power, game board, and monitor all separately, one at a time. But it's all doable. Feel free to post any other questions here.
 
Could be a fuse in your power brick on the floor, or something wrong on the AR-II board. I think what your calling the MCR, is the PCB stack to the right of the cabinet? You will want to check the smaller 6"x12" board straight ahead which is the AR-II board.

I live reasonably close, so if you get stuck I might be able to stop by and check it out.

Thanks. I'm referring to the AR board. The one mounted to the back of the coin box. The 23v side is good and the 5v side is dead when testing at the looped test points. I'll check the fuses on the brick. Although, it's never been a fuse for me. Can't get that lucky. There is an LED on the main PCB that I assume should be lit but it's not. I also forgot to mention that there is no 10.3vdc either. Thanks guys. I'll do some checking on the power brick and report back.
 
Test your voltages on the AR-II first. You should have 12-14VDC on the 10.3V test point, and 5V on the + side of C1. It sounds like you have +/-23V on the right side, which are used for the video section of the game board, which generates the XY voltages for the monitor.

If you are missing the 10.3V, you have an issue with your power brick (either a bad bridge rectifier, and/or bad big blue cap, and check all of the fuses).

If you have 10.3V but no 5V, you have an issue with the AR. Look to see if R29 and/or R30 are burnt. If so, you have an issue with your edge connector (which is either dirty, and/or the pins are stretched out and are not making contact with the fingers on the PCB). You can clean the edge connector, repair the pins, and replace the R29 and R30 (both 10 ohms, 1/4 watt).

If the resistors are ok, replace the 2N3055 on the AR. That should get you 5V again. But without 5V, nothing will run, which is why there is no 5V LED lit on the game board.

There is also no need to use a switcher in these, and it's not really straightforward to do anyway, as the AR also provides the audio amplification, so ditching the AR requires separate audio amps. It's just easier to fix the original supply, which is not that hard, and they are perfectly good systems when properly repaired. I can walk you through it, if the above doesn't work.

Be aware you may have other issues, but for any vector game, you want to attack the problem in stages, verifying power, game board, and monitor all separately, one at a time. But it's all doable. Feel free to post any other questions here.

Thanks! I'll do some testing and report back. Opening a local arcade with a partner and all our 60+ games are up and running except this Tempest and I would very much like to get it going.
 
Thanks! I'll do some testing and report back. Opening a local arcade with a partner and all our 60+ games are up and running except this Tempest and I would very much like to get it going.

Well if you want to test the Main PCB in a working Tempest, your welcome to stop up to Sterling and try it out in mine just to verify it's good.
 
Well if you want to test the Main PCB in a working Tempest, your welcome to stop up to Sterling and try it out in mine just to verify it's good.

Awesome. May have to take you up on that if I can't get it going.
 
So I tested all the fuses. All good. Reseated the edge connectors (again), and it sprang to life! Chalking this one up to bad connections on the fuse holders. Doesn't get much luckier than that. Thanks everyone!
 

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So I tested all the fuses. All good. Reseated the edge connectors (again), and it sprang to life! Chalking this one up to bad connections on the fuse holders. Doesn't get much luckier than that. Thanks everyone!


Good work.

Be aware that long-dead vectors like to run for a couple of days after being brought back to life, and can often develop other issues in the first week or so, if they haven't been gone over. Just a heads up, in case it starts acting up.

Also, it is highly recommended that you reflow the header pins on the monitor's deflection board, and install an LV2000 low-voltage replacement board on the deflection board as well. These are must-do items IMO, especially if you want to run it for long hours, and avoid future issues.

If you run into any other problems, just post 'em here.
 
Good work.

Be aware that long-dead vectors like to run for a couple of days after being brought back to life, and can often develop other issues in the first week or so, if they haven't been gone over. Just a heads up, in case it starts acting up.

Also, it is highly recommended that you reflow the header pins on the monitor's deflection board, and install an LV2000 low-voltage replacement board on the deflection board as well. These are must-do items IMO, especially if you want to run it for long hours, and avoid future issues.

If you run into any other problems, just post 'em here.

Great info! Many thanks!
 
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