Yet another Tempest Repair Thread

rainman154

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I picked up another Tempest with little knowledge of it's status.
Here is what it is doing...
1) Both player 1 and 2 buttons light and blink.
2) When plugged in, there are some "clicking" or "knocking" noises that happen.
3) Red light on board and on monitor low voltage stays on. I DO have neck glow.
4) Every so often the monitor flashes a little bit of the game picture. (colors look great) LOL!
5) No coin up.
6) No sound.

I figure I am going to start at the power supply and test all the connections. Other than that, does anyone have any thoughts on these "symptoms"?

I followed this video and everything checked out fine. https://www.youtube.com/watch?v=C1pVTzEF3ZA Although I was at 15+ rather than 14+ on DC.

One thing was that the Sound Board read at 10, rather than 5, which is what the video suggests (5).
 
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I picked up another Tempest with little knowledge of it's status.
Here is what it is doing...
1) Both player 1 and 2 buttons light and blink.
This is good. It means that you have clock.

2) When plugged in, there are some "clicking" or "knocking" noises that happen.
Likely the coils on the coin door.

5) No coin up.
6) No sound.
How do you know it doesn't coin up without sound or video?

I figure I am going to start at the power supply and test all the connections. Other than that, does anyone have any thoughts on these "symptoms"?

I followed this video and everything checked out fine. https://www.youtube.com/watch?v=C1pVTzEF3ZA Although I was at 15+ rather than 14+ on DC.

One thing was that the Sound Board read at 10, rather than 5, which is what the video suggests (5).

If this is the +5REG line, that's not good. There's a pot on the AR2, see if you can get it down around 5.10-5.15v. If not, you need to rebuild that.

And yes, get it in test mode and see what that reports. Read the manual to understand the things it may tell you.
 
Well good news, I got it in test mode. Screen looked pretty good.
Here is what it showed.

I tested both coins, player 1, 2 and fire, super zap + spinner. All made sounds and registered.
Still no game though. I really don't know how to read this test screen. What does the 8, 39 and M mean??
Thoughts???

Possibly the AR2 AND the board are bad?
I was only able to get the AR2 down to around 9.

094EC6D1-9928-4045-966A-6EDAAA67F7EF-9054-000006F166CFA23D.jpg
 
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Well good news, I got it in test mode. Screen looked pretty good.
Here is what it showed.

I tested both coins, player 1, 2 and fire, super zap + spinner. All made sounds and registered.
Still no game though. I really don't know how to read this test screen. What does the 8, 39 and M mean??
Thoughts???

Possibly the AR2 AND the board are bad?
I was only able to get the AR2 down to around 9.

094EC6D1-9928-4045-966A-6EDAAA67F7EF-9054-000006F166CFA23D.jpg

M is mathbox error, check your board interconnect.

Are you sure you're measuring the +5REG line? There's a 10v output from that board, too. Don't run your board at 9v.
 
Another mystery...
Here is a shot of the volume pot with 2 wires not connected to anything. Where do they go?
Also, here is a switch at the bottom of the cab with nothing attached. What does it belong to??

85589DA6-1045-4101-B119-5E9BDA5902ED-9054-000007024B64406B.jpg


C3AD3829-B482-41A9-BB1D-AF5712091CA3-9054-000007025030540D.jpg
 
M is mathbox error, check your board interconnect.

I checked the interconnect and reset the chips. Now the M is gone and the numbers are 8 and 2??

Is it time to start shopping for a new board? This one is in really clean, I would love to just repair it.
 
I checked the interconnect and reset the chips. Now the M is gone and the numbers are 8 and 2??

Is it time to start shopping for a new board? This one is in really clean, I would love to just repair it.

Progress! According to self-test the 8 means bad ROM chip at L/M1 and the 02 below it can be ignored.

If you got it in test mode with a switch on the coin door, the loose wires are for an alternate test switch/location.
 
Progress! According to self-test the 8 means bad ROM chip at L/M1 and the 02 below it can be ignored.

If you got it in test mode with a switch on the coin door, the loose wires are for an alternate test switch/location.

So who has a GOOD L/M1 Rom I can buy??!!!! LOL!!

Also, how do these go bad?
 
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So who has a GOOD L/M1 Rom I can buy??!!!! LOL!!

Depending on the type of rom, I can probably program one for you. L/M1 just signifies the location on the pcb. The rom is located between Columns L and M, in row 1.

Also, how do these go bad?

Rom rot. Over time, ambient light, static charge, etc can cause the data in the chip to get corrupted.

Don't forget, the rom socket could be bad too. Best way to rule that out is to test for continuity between the top of the chip legs and a corresponding component downstream on the bottom side of the board. That will prove that each rom chip leg is making proper contact.

Shoot a picture of the offending chip - maybe I can program one for ya. :)
 
Another mystery...
Here is a shot of the volume pot with 2 wires not connected to anything. Where do they go?
Also, here is a switch at the bottom of the cab with nothing attached. What does it belong to??

85589DA6-1045-4101-B119-5E9BDA5902ED-9054-000007024B64406B.jpg


C3AD3829-B482-41A9-BB1D-AF5712091CA3-9054-000007025030540D.jpg

These cabs (and other Ataris of the era) came with two different kinds of coin doors. The US coin door had a three-position test/reset switch mounted on the coin door, while the foreign coin doors did not have room for a switch. Those two leads are the test lines, and a switch would be connected to them and mounted under the volume pot for foreign cabs.

While the switch is similar to the kind you'd use for that setup, I think it's just trash. There's nowhere else it could have come from.
 
Progress! According to self-test the 8 means bad ROM chip at L/M1 and the 02 below it can be ignored.

If you got it in test mode with a switch on the coin door, the loose wires are for an alternate test switch/location.

WINNER WINNER CHICKEN DINNER!!!
Thanks to Alejandromad I was able to get a replacement ROM at L M1 and guess what...
3904C7DF-9208-4FCB-95C1-BC469F005B1C-111-0000000256EA0DC4.jpg



BOOM GOES THE DYNAMITE!! Very happy to have a nice working Tempest. Easiest fix ever. Damn this game is fun.

Thanks to all those who helped with advice on this tread!
 
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