Atari Battlezone arcade (1980) repair, part 3 

Awesome work preserving that old machine!

Thanks for this video. I purchased my own Battlezone game 6 months ago then the graphics stopped working after a power outage. This helped me to at least remove the monitor.

the aux board generates all the 3D vectors. So that includes the tank objects, terrain features, the horizon and the radar scope, timer and score (in red) It could be RAM failure, but usually that would cause vertex vomit. So I think your 3D aux board is not generating output to feed into the vector list

the heatsink compound should be on both sides of the mica disk, because it is supposed to transfer the heat while avoiding air gaps. Mica itself is a good electrical insulator while at the same time it is a moderate heat conductor, but without a good thermal contact to the sheet metal underneath it will not sink the heat.

Can't wait for part four. This video was great!

It was great fun to watch someone very smart figuring out a complex system on the fly... nicely done! I think the missing graphic elements are due to flakey vector ROMs (same ones you pressed on to get it to boot). The vector state machine, which is essentially a processor built out of just logic gates, uses subroutines to draw various shapes/letters/etc, so a bad ROM can cause whole objects to disappear. Try running the self-test, it does a good job of verifying basic ROM/RAM/etc. Cleaning and reseating the ROMs may clear it up, at least temporarily. The sockets on these boards are pretty weak after 40 years(!), so they may need to be replaced to make it reliable. Another possibility is a problem in the Z output that is causing some intensity levels to not appear at all. Good luck! Working on these games gets more fun as you learn more about them.

Any update? Did you get it working? Is there going to be a part 4.

Great long form diagnosis, love it! .. now to get oscilloscope quake running sending the vectors out to the screen :D

Your absolutely right with the missing bits in the game, you are missing, 1) mountains 2) the radar scope ( supposed to spin and show the location ( direction ) of the enemy tank ) 3) shapes ( pyramids, cubes .. ) that you can hide behind perhaps time to checkout those roms / sockets hehe Great fault finding though, super logical and thorough, looking forward to the next installment :).

I’m impressed!

Definitely worth replacing the 2114s on these boards. I fixed a Centipede board that used the same RAM (obviously not a vector game, but produced around the same time by Atari). Also had a similar problem with Atari Star Wars (also had broken solder joints).

Looks like the radar display was also missing. One of the cases where an MSO scope would have been useful. Hook the digital channels to the inputs of the DAC and an analog channel to the output of the DAC in circuit and see if the output corresponds as expected to the inputs.

Hi Robert, You need to reseat all socketed chips with power off and power cord connected to maintain earth. Make sure you touch earth before you touch the chips. Next, after reseating the chips power on and all might be well. Remember, you examined the screen after you reseated a live chip. Well, the code to generate the background sprites may have already been called into ram (but failed) and you missed the window since the chip was not in good contact and was reseated long after the initialization took place.

part 4 please ... you still haven't taken over the world!

Very enjoyable! You had me yelling at my screen, however, to probe the watchdog reset signal. That might have made shorter work of finding the problem with the socketed chip. I'm hoping you're just a bad RAM chip away from being up and running. Get the self test running and see if the board itself is hollering about any ROMs, RAMs, or PROMs.

To switch to english, on the top bank of dip switches, flip the second from the right up. Hope that helps :) -edit- Also, see if you can go into test mode. There should be a paper stapled to the back door with instructions on where to find the switch. If you can, it might beep and give you an error message you can google to find the fix too. Also, the most likely cause can be a fried resistor on the high voltage board. I admit I missed the last part so I'm not sure if you've done everything already or not, but I still hope this may help. This is a really killer game, and I can't wait for the next update!

The distorted text at 42:30 remind me of title cards from 1920s German Expressionist horror films.

check the soldering and the general state of those rom chips and sockets.. (and hope they are not damaged... getting a replacement rom might be impossible)

tfw your electronics arc weld their own loose wires back together.

Great video , very well shot and very well explained, easy to keep up with.

Nice work, I appreciate your patience. Looks like a ROM or something is not reading. Reseat everything and use some contact cleaner maybe? Also what about all those empty sockets, could that be where the terrain and object ROMS used to be?

If there are only certain video elements missing, maybe one of the VROM select lines is faulty, or some (V)ROMs aren't properly inserted into their sockets.

At exactly 3 seconds in you can see the zap was where you repaired the PCB.

Is part 4 out yet ? Great job on that so far. I think the mathbox part is not active. I understand that gives you the 3d effects and terrain.

Maybe some old dry electrolytic had reformed ?

I wonder how hard it might be too replace that tube with a LCD. All the signals are there, you'd probably just need a FPGA.

So,where is part 4 ????????????

Why was it set to German? If you are missing display objects I would start looking at the RAM or the ROMs; there is definitely a problem there. And the video looks like it could use a little bit of adjustment.

thank you for your building a CPU videos (unfortunately comments are disabled, can you change that?)!

hey - do you know the 'light bulb current limiter trick'??? plug a light bulb in series with your power cord - IF there's a fault the bulb will light up - but it will ALSO protect all your circuitry IF there is one... indispensible!!

you bring up an important philosophical question, if you shot an invisible tank is the explosion visible ?

First part in the series that didn't end in a bang. Or did it? ኧ

Surprised you would not have "reset the dip chip in the socket". As a test have a board with 6 roms chips in sockets, and see how many 55+ old hardware engineer could walk by WITHOUT pushing on the chips....

Also look at the joint at c107 at 10:07

you really should replace that very large capacitor it's called the atari big blue my battlezone would not power up because it was so bad when i first got it

cool - a german battlezone

You need a camera operator. :)