Quick and nice repair.
Bought a "Mahjong Lady Hunter (JUNK)" PCB from YAJ recently, and hey, sometimes stuff marked as junk does in fact not work.
This is a pretty cool Mahjong Game which uses a very unlicensed Batman that fights bad dudes with Mahjong.
Was stuck at startup with this screen:
Loading the ROM in mame and trying to provoke this to happen shows that "Start1" being stuck will provoke this issue. This maps to the sixth "Key" pin on the Mahjong matrix probably not working, see: http://arcademahjong.com/#mahjong-pinout
Probing that pin shows it's low, when it shouldn't be.
Tracing down where that's wired, it goes to a 74ls367 buffer (pin10), which seems to pull the input low. Can be assumed to be broken. (tape added by me to remember which IC it was when desoldering)
Swapped it from a very broken donor board, since it's a common enough buffer.
Hey works, Batman is back!
Bought a "Mahjong Lady Hunter (JUNK)" PCB from YAJ recently, and hey, sometimes stuff marked as junk does in fact not work.
This is a pretty cool Mahjong Game which uses a very unlicensed Batman that fights bad dudes with Mahjong.
Was stuck at startup with this screen:
Loading the ROM in mame and trying to provoke this to happen shows that "Start1" being stuck will provoke this issue. This maps to the sixth "Key" pin on the Mahjong matrix probably not working, see: http://arcademahjong.com/#mahjong-pinout
Probing that pin shows it's low, when it shouldn't be.
Tracing down where that's wired, it goes to a 74ls367 buffer (pin10), which seems to pull the input low. Can be assumed to be broken. (tape added by me to remember which IC it was when desoldering)
Swapped it from a very broken donor board, since it's a common enough buffer.
Hey works, Batman is back!
