Battlezone weirdness & resets

[wantdataeast]

Bringing a Battlezone back to life, was up to the point where all was good but I had some jittery obstacles, primarily the triangles; and I was having reset issues. Was also having some jittery graphics on the high score screen around center high score. I pulled the boards and used Deoxit spray to clean all the IC legs and sockets (a brass Dremel to burnish. The IC legs), did the same thing on the innerconnect cable between the PCB and the auxiliary PCB board. When I began retesting the jittery obstacle situation seemed to be taken care of, however, after a minute or so of play I got my reset issue back and now have some odd lines that are permanent on the screen during the attraction mode. I can't seem to start a game right now either; but I have still have the start up screen. Now when I go to test menu. I'm seeing a L looking graphic on the right hand side which I've circled in red. The odd Lines do not appear during the test mode as you can see.

 

[GothGirl]

Mine is super fussy with the voltage or it does similar things .... also I would check your chip sockets on the matchbox which often need to be replaced

 

[andrewb]

You have a mathbox error on the aux board.

This can be caused by many things. Dirty chip legs and bad connections to sockets is a common one. However if you already dremeled and DeOxited the legs, that probably isn't it.

If this is a machine that you just got running, I'd suspect something actually failed on the aux board. It's very common for these boards to blow chips in the first few hours or days of use, once you get them running again. I burn-in test all boards I repair, and at least 50% of the ones that have been sitting for 6 months or more blow something in the first few days.

You can manually wiggle and press on chips (and the interconnect) while it's running in test mode, to see if it goes away. But if not, something is bad on the aux, or the interconnect. (Check the solder joints on both sides). This is where it helps to have a spare good aux board, so you can swap all socketed chips to start. If that doesn't fix it, you have to get into debugging the rest of the aux logic, which usually requires a signature analyzer.

If it's the logic, you might need to send it out. There won't be much more you can do beyond swapping out the socketed chips. Whatever you do, don't start recapping boards, replacing sockets, or buying any other 'mods', as none of them will fix it. It's not your big blue, it's not caps, and a high score kit won't fix it, so save your money.

 

[FrizzleFried]

Mine is super fussy with the voltage or it does similar things .... also I would check your chip sockets on the matchbox which often need to be replaced

... I was about to say "welcome to Battlezone normal operating procedure"...

 

[andrewb]

Also, what is your 5V measuring, and where are you measuring it?

 

[VectorCollector]

Yeh, if no 3D objects then suspect first a bad connection to/from the MATHBOX AUX PCB and/or bad socket.
Start with the easy stuff.

Also, the MB AUX typically has slightly lower +5VDC value than the main AVG board. Just insure it's well above +4.75VDC (i.e. -5%).

Since "START" is associated directly with the POKEY (on the AUX PCB), and the POKEY affects the databus, that is something to consider too.

 

[ArcadeTechGW]

It could still be voltage dropping to the Aux Board - check that first. Low voltage and TTL logic don't play well together.

 

[wantdataeast]

Also, what is your 5V measuring, and where are you measuring it?

Yeah.. looks high on the Aux board. See pic

 

[wantdataeast]

You have a mathbox error on the aux board.

This can be caused by many things. Dirty chip legs and bad connections to sockets is a common one. However if you already dremeled and DeOxited the legs, that probably isn't it.

If this is a machine that you just got running, I'd suspect something actually failed on the aux board. It's very common for these boards to blow chips in the first few hours or days of use, once you get them running again. I burn-in test all boards I repair, and at least 50% of the ones that have been sitting for 6 months or more blow something in the first few days.

You can manually wiggle and press on chips (and the interconnect) while it's running in test mode, to see if it goes away. But if not, something is bad on the aux, or the interconnect. (Check the solder joints on both sides). This is where it helps to have a spare good aux board, so you can swap all socketed chips to start. If that doesn't fix it, you have to get into debugging the rest of the aux logic, which usually requires a signature analyzer.

If it's the logic, you might need to send it out. There won't be much more you can do beyond swapping out the socketed chips. Whatever you do, don't start recapping boards, replacing sockets, or buying any other 'mods', as none of them will fix it. It's not your big blue, it's not caps, and a high score kit won't fix it, so save your money.

I personally don't mind spending the minimal cost on cap kits and big blue on the Regulator/ Audio board and PCB board, so I always do that. And that has been done on this machine. My voltage is running high on some parts of the Regulator/Audio board. (Unfortunately I forgot to check at the +sense and -sense test points). I tried to adjust the 1k pot at R8 which I am assuming adjusts the voltage in that area… no voltages dropped. All voltages here were taken when the pcb and aux pcb were disconnected.

 

[andrewb]

Yeah.. looks high on the Aux board. See pic

You should be using the 5V and GND test points on each board (main and aux, measure each separately).

What were you using for GND when you did the measurements above? You can't be getting higher on the aux than the main, unless you have your black DMM lead on something that isn't GND. Also, you don't want to use chip pins, because the corner pins are not always 5V and GND on some chips (which is the case on those bitslicer chips).

For BZ, the aux gets its 5V from the main. So if the aux is at 6V, the main shouldn't even be running. But you want the aux between 4.90 and 5.00, and the main between 5.05 and 5.15. You can't adjust them separately, so you want to spread the difference between them, so the aux isn't too low, and the main isn't too high.

 

[andrewb]

I personally don't mind spending the minimal cost on cap kits and big blue on the Regulator/ Audio board and PCB board, so I always do that. And that has been done on this machine. My voltage is running high on some parts of the Regulator/Audio board. (Unfortunately I forgot to check at the +sense and -sense test points). I tried to adjust the 1k pot at R8 which I am assuming adjusts the voltage in that area… no voltages dropped. All voltages here were taken when the pcb and aux pcb were disconnected.

It isn't about the cost. It's more about preserving originality. The caps on AR's are never worn out, or even close to it. I've rebuilt and tested hundreds of them, and never measured a single bad one.

Same thing with the big blue. It's simple to test how healthy one is. And if it measures ok, there's no need to replace it. Procedure here:

tempest reeboot issues

One of my tempests has been acting up lately. The game will play fine for a little while..may get a game or two in, then it starts rebooting to the point where I can't get past a single level. I've swapped out the boards and PS and the issue persists. I checked the voltages on both PS and I'm...

forums.arcade-museum.com

Think of these games like an old all-original 1965 Mustang you found in a barn. If you want to preserve as much value as possible, you want to replace as little as is needed to get it working, and keep everything else as untouched as possible. People have a false belief that the more you replace, the 'better' you're making the game. But you really aren't. You're just spending money and time, and removing originality. You aren't making the game any more reliable.

All you need to do on an AR is replace the 2N3055 bottlecap transistor, as that is the one part that does the heavy lifting, and those do wear out, and we know that because we've seen plenty of bad ones. However when they fail, they can send 12V to your game board and damage it. So that's the single most critical part in the whole game. Most other things (including the big blue) can be bad, and the worst that will happen is a fuse will blow, or the game just won't boot. So most original parts are fine to run with, if they still measure ok. You can measure the health of caps with a cap meter that measures ESR (Equivalent Series Resistance). Invest in one and you'll see when a cap is actually bad, and by how much.