Tempest PCB not working

wmacmonagle

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Just picked up the Tempest PCB and tested in working Tempest Cabinet and i only see two red players 1/2 buttons lit up and i see two red light led on the pcb lited up.. but doesnt show any pictures or game sound.

.. Repairable or ?? I could trade in + Cash for working one?? Shoot me pm or lmk what s the solution to it.

Thanks man

wmac
 
Just picked up the Tempest PCB and tested in working Tempest Cabinet and i only see two red players 1/2 buttons lit up and i see two red light led on the pcb lited up.. but doesnt show any pictures or game sound.

.. Repairable or ?? I could trade in + Cash for working one?? Shoot me pm or lmk what s the solution to it.

Thanks man

wmac

I would rather try to help you get yours working but if you just want it fixed here you go:

http://stores.ebay.com/ARCADE-CIRCU...b=3057004&_sid=40238877&_trksid=p4634.c0.m322

and here is some other options for you.....

http://www.ebay.com/sch/i.html?_fro...13&_nkw=tempest+pcb&_sacat=See-All-Categories
 
I tried the Tempest board repair service on ebay. If this is the same one his name is David Haney of Austin, TX . He kept my tempest board-set for three months only to return it to me in the same condition of that I sent it to him.
 
I tried the Tempest board repair service on ebay. If this is the same one his name is David Haney of Austin, TX . He kept my tempest board-set for three months only to return it to me in the same condition of that I sent it to him.

That is good to know. I hope he didn't charge you for that repair!

Check the sticky at the top of the forum for who repairs what. Other than that Riptor and a few others I think do them boards.
 
Hey guys,

I'm in the same boat. My Tempest has been dead since '93 (yeah really) and I'm finally in the mood to try and fix it. I'm facing compound issues that make it a real challenge.

First one to solve is that I have two Tempest board sets that both exhibit the same problem. I took them and tested them again in a working Tempest game today to confirm they were both bad.

The problems they are both exhibiting is no video output. They will coin-up and play but neither board is generating any video output. Given I have two boardsets with the exact same issue, is this a common failure mode? with a hopefully common fix?

I'm located in Austin,TX.

Thanks.
Scott
 
Usually I'd recommend sending them to Elektronforge, but I've been waiting for him to repair a board for me for over 2 months now :|
 
As mentioned, resoldering the inter-board connectors is a good thing to try first.

Additionally, if the boardset coins up and can be played, but no video.... Sounds like it is a problem within the analog section. Depending on board revisions (and they are different ones). Usual suspects are the TL081 (8 pin), or the MC1495L, or the AM6012PC (DAC312) chips for either the X or Y analog outputs. When Analog is working, you should see up to +/- 2V fluctuating on the X and Y test lugs. If it measures around 0v on either, then it is dead and the spot killer on the monitor will be triggered. If dead, you can look at the OpAmp or D/A ICs for that axis (chips mentioned above).

One check would also to see if the AM6012PC is getting digital inputs and subsequent analog output (I believe the analog comes out on pin 15). If you are not getting any digital inputs to one or both of the D/As, then the problem is more likely back in the vector generation area which is harder to diagnose.

Since, you can coin up and hear a game, this tends to mean the program runs and thus your program and vector RAMS/ROMs are functioning properly. A completely dead board would need a different approach to debug the problem - starting with the 6502A processor and whether it is being continually reset because program code is not clearing the Watchdog...... which could be bad data/address buffers, bad ROMs/RAMs, bad sockets, etc. etc. etc.
 
Aww shoot Kip,you didnt tell me you had a space invaders pin...We would have had a different trade going for that fluke! ;-)

The TLO82s do fail alot, so Id start there.
 
Diddo, First post was for a completely dead board so it is most likely a RAM/ROM issue and the program is not running properly and causing the watchdog to fire (6502A is continually resetting). A logic probe on pin 40 of the 6502A chip would confirm this.

As for the subsequent posts on the boards running blindly, start with the TLO82 chip(s). A DMM on the X & Y lugs - looking for voltage fluctuations between +/- 2V would tell you which TL082 to try first. No voltage would be the side to try first. BTW, Radio Shack does carry this chip in most stores (for a premium price that is....).
 
No, Tempest uses a 6502A processor chip which runs faster then the 6502. But it probably is not the processor chip. If the proc chip is resetting, then it usually mean the program code is not running properly which allow the watchdog to clear. This is what is most likely causing the reset to be constantly triggering. If you still have the reset triggering after you prove the RAM and ROM are properly working, then a problem in the vector generator can also cause reset issues. All in all, these problems are hard to debug with just a probe. You can look at the MPU address and data buffer chips to see if you have any pins stuck pins (high or low). Beyond that, having the proper test equipment with make much lighter work for finding the problem. One of thing to try is re-sitting the MPU and ROM chips and/or even replace the sockets on these chips.
 
Thanks for the info. I'll start to look at the ram/rom chips. I've re-seated everything to no avail. I'm going to have to get lucky and stumble upon it, or send it to somebody eventually.

I really appreciate your input.

chris
 
Thanks for the info. I'll start to look at the ram/rom chips. I've re-seated everything to no avail. I'm going to have to get lucky and stumble upon it, or send it to somebody eventually.

I really appreciate your input.

chris

Try some of the low tech methods first. Feel for very hot chips, measure voltages at different chips, and probe baby probe with that logic probe. Especially if you are new at it, these are skills you are going to be needing and need to be comfortable with.
 
Tempest had been sold to Tron Guy. Referred to him this thread cuz i see many good information here. Again thanks for the support!..

GO TEMPEST!!!

Try some of the low tech methods first. Feel for very hot chips, measure voltages at different chips, and probe baby probe with that logic probe. Especially if you are new at it, these are skills you are going to be needing and need to be comfortable with.
 
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