Burglar X (Unico, Korean) - Stuck at garbage screen

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    • Burglar X (Unico, Korean) - Stuck at garbage screen

      A friend of mine gave me a pretty rare Burglar X to check, but i wasn't able to find any schematics, also my knowledge is very little when logic decoding is involved.
      The board is stuck at garbage screen.

      Main program roms pulled, dumped, compared and ok with mame.

      Halt and Reset of the CPU are both HI, i see an initial Low transition for the reset, very briefly. From what i've learned, this is a good thing.
      Pulled out both work rams (256 32k), tested good in my TLA866 and Neoloch sram blade.

      I started to probing around, even if the cpu is "on the go" there's no activity at all, adress and data are both silent on all pins.
      Main program rams are silent too, and they are not even selected by the CE (HI all time)
      Also program eeproms are silent, but the CE is Low.

      So as my very scarse knowledge supposed, i removed the 68000-12, tested good on my pcb bench, but changed it anyway. The same.

      I went to inspect the two crystals (a 14.81mhz and a 32Mhz), output for 14.81 is pulsing (no low or high), 32Mhz is stuck HI with no pulse. Since i dont'have nothing to check them, i just swapped them with others, but the result was the same.

      All of the other rams i saw by pointing at them had very good activity, also the board is in awesome condition, i did hovewer clean up a bit.

      So i must suppose this is a logic (?) problem. Unfortunatly what i've learned above was all by myself, but actually no one teached me how these 3 "items", cpu, ram and eeproms, works toghether.
      I was hoping someone here can help me out and maybe finally learn something rather than just be a conversion guy the whole time (or a piggyback/ramswapper/solder-desolder boy)

      I would like to learn more. Please open my mind ^^