BZ Reverse Right Confusion

melchman

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So Battlezone is nearly complete. I am stumped by a right reverse problem though. We have two boardsets, both recently repaired. Set A runs the games fine except the Right tread controller does not go in reverse. When in test mode, the switch test indicated it is not firing. We opened it up and replaced the wiring that was chewed by the last repairer who put the screw through the wire bundle.

We tested the switch for continuity: good
We tested to the CP Harness: Good
We test to the PCB Harness: Good
Connected and Test Mode: FAIL

Set B has a K1 Problem (see Attached). If I move Set A's K1 to Set B then Set B boots and has the same failure on Right Reverse. Tested continuity on the interboard connector, all good.

How do I get the board to "see" Right Reverse?
 

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So you've verified all the way to pin 16 on the harness plugged into the Aux board (white/black) goes to ground when pulling the right controller back, but both Aux boards ignore it?
 
Yes, with the harness off. I suppose it is possible pin 16 is not making good contact with the boards. Ground must be fine as all other control work.
 
So Battlezone is nearly complete. I am stumped by a right reverse problem though. We have two boardsets, both recently repaired. Set A runs the games fine except the Right tread controller does not go in reverse. When in test mode, the switch test indicated it is not firing. We opened it up and replaced the wiring that was chewed by the last repairer who put the screw through the wire bundle.

We tested the switch for continuity: good
We tested to the CP Harness: Good
We test to the PCB Harness: Good
Connected and Test Mode: FAIL

How do I get the board to "see" Right Reverse?

Well, if you're certain that the wiring is good, then there are only a few things on the PCB to check...

-first check for physical damage; scratches, gouges, damaged traces, shorted pins, etc. etc. esp in the areas of the components listed below.
- there are only a few components in the "R-REV" (right reverse) input circuit; R48 is an in-line current-limiting resistor (make sure it's not open); R40 is a pull-up resistor (make sure it's not open); C31 is a noise suppression cap between the input & GND (make sure it's not short).
- after that, it's straight into the POKEY. Try swapping in a good pokey.
 
Set B has a K1 Problem (see Attached). If I move Set A's K1 to Set B then Set B boots and has the same failure on Right Reverse. Tested continuity on the interboard connector, all good.

I have a BZ, but somehow I have no idea what a "K1 problem" is...
 
OK, I'm up to speed now.

So you've positively identified the source of that problem; bad EPROM, as it goes away when you swap in the EPROM from the other board. You need a new EPROM programmed (or a Braze kit, which eliminates the need for them entirely).

As far as the control issue, I re-read the thread, and as douglasgb implied.... it's sounds a little funny that both aux boards (assuming your A & B sets are full sets; both main and aux boards) have the same input issue. That certainly does make it sound more likely to be a control/wiring issue. As suggested, check the voltage on that pin (or where it goes on the PCB) with the game on, and see if it's 5V and goes to 0V when the control is activated. A logic probe is handy for this sort of thing, but a DMM will work fine.
 
Depends on your logic probe. Mine has seperate LEDs for high and low... not sure how yours works. Did it come with any documentation?
 
Alrighty then, it's just as you expected. LED on normally, and off when the switch is activated (closed), cause that pulls it to ground.

You can check it both at the edge connector (on the PCB), and at the Pokey (pin 14).
 
Edge Connector

EDGE CONNECTOR!!!!

We went in and "raised" the pins on the edge connector plug. Amazingly it worked!

We tested the switch, then the wires and then we "closed the switch" on the board to prove the board was working. Everything test out fine. Finally adjusted the pins inside the connector and got the real result.

Is there a rebuild kit for Atari style edge plugs?
 
Glad to hear you got it fixed.
Even happier to hear that you want to go ahead and fix it right, and re-pin the connector.

If your edge connector housing is Amp, you're in a tough position, as the crimp pins are hard to find. If it's a Molex, you can still (for the moment) get crimp pins for it. You'll have to look very closely (likely with a light and some magnification) to find the manufacturer's mark on it.

The Molex split (bifurcated) pins for 0.156" edge connectors can be bought from a variety of the usual suspects... Bob Roberts, GPE, & TwistyWrist just to name a few.
 
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