TRON Repair

[studiopaul]

checked all cables and swapped chips..still same problem

any suggestions?

 

[studiopaul]

Tron repair?

I took a few pics to show the problems having.
Game plays 100%, just cant see whats being played in some of the game.
X-Y joystick and game play feels fine.

Start window? should it display icons on maze sections?

http://forums.arcade-museum.com/attachment.php?attachmentid=62090&stc=1&d=1297787159

No light cycles

http://forums.arcade-museum.com/attachment.php?attachmentid=62091&stc=1&d=1297787346

No tanks

http://forums.arcade-museum.com/attachment.php?attachmentid=62092&stc=1&d=1297788078

No tron grid bugs

http://forums.arcade-museum.com/attachment.php?attachmentid=62094&stc=1&d=1297789133

missing parts of cone

http://forums.arcade-museum.com/attachment.php?attachmentid=62093&stc=1&d=1297788201

So I switched out chips to see if problem would move.
result was staying the same...would the memory on graphics board indicate a different fault or same fault due to lack of memory total???

Dont know if pics imbeded. or if have to copy paste links

Thanks again

 

[studiopaul]

Any tron experts seen this problem?

 

[KI4SWY]

im working on similar problem

http://forums.arcade-museum.com/showthread.php?p=1525511#post1525511


i pulled one of the 74ls157 on my board, and it removed the tank/bike, so maybe possibility same area?

im printing this now: http://arcarc.xmission.com/PDF_Arca..._Midways_MCR_II_&_III_Systems_(July_1983).pdf

and have access to LA/Scope, so hopefully can figure out.

 

[benkeezer]

I sent mine to cdjump. He did a great job repairing them and was very reasonable. Quick turnaround also. I was having the same problem as yours.

 

[KI4SWY]

mine looks to be a problem in the picture number latch (n3) , now that i read thru the theory of operation, i can fire up the logic analyzer, and look at each chip to make sure its properly functioning.

 

[KI4SWY]

mine looks to be a problem in the picture number latch (n3) , now that i read thru the theory of operation, i can fire up the logic analyzer, and look at each chip to make sure its properly functioning.

if this picture # latch is not messed up, im going to assume it before the object ram, as then its not loading the object ram with the correct data. or not reading the object ram correct.

it would be nice if someone had a made a set of test roms for the cpu to test graphics board.

 

[studiopaul]

I replaced all video ram chips 93422 - 8222

2114 -2cb

I still have same fault????

 

[KI4SWY]

you may have a deeper issue with a 2-1 mux, or the chip @ n3.

** i would save your old ram chips, as they appear good then if you replaced them all with no change **

 

[studiopaul]

Ive been checking 5 vs ..all seem ok...
any suggestions on where to focus..i have a scope still learning to check readings.

Anyone want to help a newbie?

 

[KI4SWY]

at this point your going to want to pull up the data sheets for the chips, and understand how they work.

if you have a 4 channel scope, you can then monitor at least 4 pins at a time, and just check the data to the logic chart.

( a logic analyzer would be better suited as they usually have 16+ channels )

start with the ls157's