Jun 122016
 

Got an ESP Ra.De. board with faulty graphics:

esprade2

While looking for some suspicious signals on the GFX area, I found two PALs at locations U31 and U34 that got nothing on their output pins. U31 had healthy looking pulsing signals on its input pins but U34 had some input pins with no signal. These were in fact coming from U31 so that was totally normal.

These PALs are soldered and weren’t dumped yet so I needed to find a working board, desolder the PALs and dump them which was not easy due to the rarity of that game.

Anyway, I desoldered the two suspicious PALs from by board.

esprade1

I tried to dump them but got an error at pin #20 which is the +5V pin. Sounded they really were faulty as they got no power in order to work properly.

Finally, a good friend got a working board and kindly lent it to me so I could dump the PALs (they were unprotected).

I put sockets on my board, plugged new reprogrammed GALs in place (PALCE16V8 are compatible with GAL16V8). Everything looks perfect now:

esprade4

There is a total of 4 PALs on this board. I dumped all of them. They are available on JAMMArcade.net

Here’s a picture of the board with the two replaced PALs highlighted in red:

esprade0b

 Posted by at 1:01 pm