Feb 202016

I never had a Bubble Bobble PCB in my collection so recently I bought this bootleg board (original one is too expensive for my taste) called Super Bobble Bobble :


When I powered it up, at first glance it seemed to play fine except for the lack of sound which I promptly fixed reseating and cleaning the sound CPU ROM.But playing some games I noticed that screen was yellowish :


Shorting some data/address lines of various RAM I could identify the ones related to palette circuitry, two TMM2015 (6116 compatible)


Probing the lower one with a logic analyzer revealed that some address lines were stuck low:


This lead me to remove and testing the chip out of circuit where it failed:



With a good RAM chip correct colors were restored:


End of job.

 Posted by at 4:51 pm

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