Tempest repair

rod90

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I am just starting to work on my Tempest and found these two wires next to two lugs. I am assuming that they go here, but the online schematics do not even show this type of power brick.
 

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Those two wires hook up to the chassis of the brick, that screw that's on the right side of the pic(closest to the transformer) needs a nut on it so you can hook them up there.
 
What James said. Those are the field grounds (or frame grounds), which are basically just safety grounds, that connect to all of the metal parts of the cab. So if any of them get accidentally electrified by a loose wire, etc, they will short to ground, and a player (or technician) won't get injured. They aren't critical to the functional operation of the game, but yes, they connect to those lugs on the brick.

I put a wing nut on mine, so I can remove them easily if I need to swap bricks (as I occasionally swap bricks in and out my cab for testing.)
 
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The location was pretty obvious, but the manual does not show them. Thanks to both of you.
 
I am making progress on this. The edge connector felt loose, so I thought that I would replace it. In the mean time, I was doing some other testing. I had it hooked to my scope on XY mode. It was showing gameplay, but the image was reversed. My size and lin pot were set to min and I could not get it any smaller.

Today, I had time to re-pin the connector. When I hook it back up to the scope, the image is no longer reversed and my output values for Y are lower. It no longer goes of off the scope screen.

It now shows a DC max and min 1.6V. Is this still too high to hook back up to the monitor?
 
Put all the pots on the game board to center, and measure the AC and DC on the XOUT and YOUT test points.

As long as the DC on both is between -1V and +1V, and the AC on both is below 4V, you should be ok to connect the monitor.

Slight note regarding the above, the DC for YOUT will jump around. It is normally around -1V during the gameplay section of the attract mode, but it will creep up to around 3 to 3.5V briefly during the expanding 'TEMPEST' logo, then return back down after the logo. That part is normal.

There is also some room to adjust them around with the pots, which is why you want to measure with the pots centered to start with. If the values are way off with them centered, you likely have bad chips in the analog section. You can get away with some adjustment, but if you are needing to crank them to min or max to get the values in the ranges above, you have other issues.
 
You should be able to adjust your volts/division knobs on the oscilloscope to get an image that fits.

Sorry, but that's bad advice.
Since X and Y ranges are similar, the CH1 and CH2 should be set at the same value (i.e. 1V/div) to insure the LOGIC board is outputting the correct ranges. To adjust the sizes, use the LOGIC board pots. If the pots don't work, then fix the analog section or test/replace the pots etc.
 
It isn't bad advice.
I could have elaborated.
Once it was stated that the image was reversed, I assumed the original poster didn't have a lot of familiarity with scope settings.
 
It isn't bad advice.
I could have elaborated.
Once it was stated that the image was reversed, I assumed the original poster didn't have a lot of familiarity with scope settings.
I do not know what led you to that?
I do not know Tempest boards and what should be displayed. I am just using the scope for a graphical representation and that is all.
 
I made some progress today. I got my parts for the HV and deflection and rebuilt it again. It made no difference. With the HV cage not installed, the LV 2000 works. With it installed, the +Vout led goes out.

I looked at my HV cage and noticed that R920 was burnt. I took it out and it measured within value. I replaced that resistor and the 555 timer. After reinstalling the HV cage, I now have a buzz and a reading of 18.v with my HV probe. After a few seconds, the buzzing quits and the LV 2000 shuts down the +Vout. This will reset itself upon power down and will repeat the condition.

Where else do I need to look in the HV cage?
 
Does your HV cage have the HV trip circuit? (The P329 does, and the P316 does not).

If it does, it will have the extra pot near the front of the cage. If this is the case, it sounds like you may need to adjust/calibrate the HV trip level. Instructions are in the 6100 manual.

If not, report back.
 
Ok. If that's the case, the next step is to replace all of the Zener diodes in the cage (if you have not already), as those are a very common issue.

There are two 13V 1W Zeners (ZD900 and ZD901), and one 150V 1W one (ZD902).

Be careful to replace ZD900/901, not confuse them with D900/901, as they are separate and different, and badness will occur if they are mixed up.
 
That is just wonderful that you can buy a monitor repair kit and still not get the parts that you need in it.
But, my kit did have the parts to repopulate the low voltage section.
 
That is just wonderful that you can buy a monitor repair kit and still not get the parts that you need in it.
But, my kit did have the parts to repopulate the low voltage section.


If it was a Bob Roberts kit, remove all of the parts from it that you may have installed, toss them in the trash, and get a new kit from arcadepartsandrepair.com. Bob's kits were full of cheap Chinese caps, and other counterfeit parts, and are not worth the trouble.

Idk if arcadepartsandrepair's kits include the Zeners, but they are easy to get otherwise. They can't include every possible part in the kits, which is why kits in general are not a silver bullet.
 
Agreed. If I didn't watch his video prior to me doing it, I might have let some magic smoke out myself.

LOL. was that the one where he rebuilt the 6100? I couldn't watch the whole thing, it started to hurt after awhile.
 
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