attempt to fix Amidar - Konami Olypmia

[vsl]

3 days ago I started again the sports malice to fix a great game from the 80's AMIDAR. To begin with, I started with the eproms, they were gone most likely because they are more than 40 years old. I had trouble programming them because my programmer didn't support 25v, so I had to buy one. So the first picture after programming the roms was a very cool carpet

After investigation and replacement of 3 chips 6P, 6K and 6J the result slightly changed :

I found two more half blown 74LS367 chips. After their replacement, the situation improved a little more:

After checking the entire address bus and data bus I found something strange that I couldn't find information about anywhere. After checking the address bus A11 is connected to ground with a jumper, as the jumper gives the option of choosing whether A11 is connected to ground or to pin 5 of 2A ?????


when is a11 connect to ground (that's how it is from the factory):


i need help about this .

 

[Lurch666]

Looking at the schematics Pin 5 from 2A is the A11 buffered output from the CPU so connecting it to GND would stop it accessing the full address range of the CPU eproms and ram so it's puzzling why the option would exist to ground it.
I would not leave it connected to GND as with it connected to 2A it appears to be trying to boot.
This PCB boots straight to the crosshatch which you are seeing albeit corrupt so it's making some progress.
Have you checked the 2114 CPU ram at 1K,1G,1J and 1H yet?

 

[vsl]

Looking at the schematics Pin 5 from 2A is the A11 buffered output from the CPU so connecting it to GND would stop it accessing the full address range of the CPU eproms and ram so it's puzzling why the option would exist to ground it.
I would not leave it connected to GND as with it connected to 2A it appears to be trying to boot.
This PCB boots straight to the crosshatch which you are seeing albeit corrupt so it's making some progress.
Have you checked the 2114 CPU ram at 1K,1G,1J and 1H yet?

Yes, I just removed all 2114 in positions 1G 1H 1J 1K and 3J 3K 3L 3M and put sockets on them. I tested with other memories, rotated them, but there is no visible change. These memories heat up like an oven, but I think that's their operating temperature.Also, 3G and 3H are very hot, but I think it's normal for them. My logic tester recognizes them as 74S416.

 

[vsl]

After a lot of investigation I found a broken path under 3D.

 

[Lurch666]

Did repairing that track fix the board?

 

[vsl]

Unfortunately fixing the path didn't help. After continued investigation half inoperative 6M 6L.
However, after changing them, another problem popped up:

I check all track around the area where I changed the chips and everything is ok.
Any help on where to look for the bouncing picture issue would be appreciated.

This is the sync signal:

the frequency seems a bit high.

 

[Lurch666]

Do you still have A11 connected to GND?