Allright ... here we go again.
Wanted to play a game of dodonpachi daioujou black label (converted cartridge), and got a dead screen. Now I have two PGM motherboards so i went on to test the cart in the other PGM motherboard and the cart worked fine?
Some of these PGM boards are equiped with the dreaded varta battery from the factory, but mine where already removed. I therefore where a bit confused as to what the issue might be. Apart it came!
(By the way, this is a rev. 5 board . You want the rev. 14 - as it has the coin-cell battery and not the leaky varta one).
From the picture above I already added the fix (the big wire). The fix is documentet a couple of places on the interwebs and apparently fixes the issue. It patches a broken track running under the connector for the additional players (3 and 4 i think).For me it's not a big issue that the additinal player's connector does not work, but if the track is not connected - you'll be greated with a black or green screen upon boot. I checked continuity with a multimeter and sure enough - no beep.
It's not my best solder work, but it's running now. Those small via are not easy to get solder to stick to.