Battlezone vector trouble.

[Jeff F]

Turned on the Battlezone yesterday and had an interesting thing happen... the text and background images are absolutely fine but any object(geometric shapes, tanks, and radar) is distorted like you wouldn't believe. Also, the word "Battlezone" on the demo screen is distorted.

Does this problem ring a bell with anyone? If so, I'd appreciate any info. you can share.

TIA,
Jeff

 

[Talon2000]

Do you get any errors in Test mode?

L, H or T

 

[Jeff F]

Nope, no errors at all and the grid looks fine.

 

[cadillacman]

put it in test mode and start tapping chips so see if you get different errors. THose are notorious for bad chip sockets..

 

[modessitt]

Reseat your ROMs and see what happens. I had one that had some corruption in the beginning of the title screen and it turned out to be a chip socket issue...

 

[timiskander]

I'd also check the socketed chips on the aux board. I've seen similar sauce from these chips.

cheers
/Tim

 

[Jeff F]

Forgot to add there's a Braze kit installed so all the EPROMs are out except the two required ones.

I tried reseating the kit and the two EPROMs and nothing changed. Also tried the "tap" method all over the board without luck. Then I put a different AUX board with a different cable and the same problem exists so it seems like it's something with the main board.


It's really kind of strange that the score, high scores, background mountains, etc are fine and the enemies, geometric shapes, and tanks are so off.

 

[CoindoorDave]

BZ

Check any interconnect cables...try unplugging/re-plugging them in.

 

[SuperGunGuru]

Maybe a bit of a long shot, but have you tried re-flowing the header pins for the interconnect cable?

 

[Talon2000]

The two required are the vector roms. Which is what you are having problems with, I would re-seat them JIC.

 

[Jeff F]

Damn... thanks for all the great ideas everyone.

I'm going to make sure the solder on the interconnect pins is good and then checksum those two ROMs. I'll also take a look at the ROM sockets and change them out if they haven't already been replaced.

Thanks again guys.

 

[road.runner]

I agree the vector ROM are most likely cause - but I have seen this with a failing RAM chip (self test is not perfect) as well as the math board 2901's (or their sockets).

 

[Jeff F]

I reflowed the pins for the interconnect and also verified the two vector ROMs but the problem still exists. Tomorrow I'm hoping I'll have time to replace the two ROM sockets.

Here's a little video I took of the problem...

 

[road.runner]

Might also pull the four 2901's on the math board....look for bent or oxidized legs. Clean them up as best you can. See if swapping them around changes your "disease"

 

[Cmndr Brain]

41000, Not a bad score. I'll have to try harder to beat that DAD character.
Sorry, can't help with your vector prob.

 

[Jeff F]

Alright... here's the run-down so far...

-swapped in known working AUX board
-swapped in known working interconnect cable
-replaced interconnect pins with new "square" pins
-check summed two vector ROMs
-replaced two vector ROM sockets
-using Braze HS kit so other ROMs are eliminated

Problem remains exactly the same.

 

[road.runner]

then it's got to be a ram going bad (my 2 cents)

 

[Jeff F]

You know... I think before I go changing RAMs out I'm going to put the Braze kit in our other working BZ just to make sure it's not something screwy there.

 

[road.runner]

if you have access to a Fluke that would be best for testing...otherwise try piggybacking a good RAM chip on each of the vector RAM

 

[Jeff F]

Nah, I just have a logic probe and old o-scope. I've never piggy-backed before but I'll give it a shot here.

Thanks again for the help.