Data East The Real Ghostbusters arcade pcb repair #3

Another Ghostbusters, and like the previous repair no video sync or output although a logic probe seemed to show the CPU was running. I expected to find a bad 74LS chip or a gouged trace on the bottom video board, but I pretty quickly found the custom chip that is meant to produce monitor sync was completely dead. The DRL40 custom takes some timing signals, has a reset line and takes a 12MHz and 6MHz clock. In return it is meant to produce monitor sync and sprites. Even though all the inputs appeared correct absolutely nothing was appearing on the output lines. Manually grounding the reset line didn’t do much either.

When I looked at the board in sunlight though a tiny crack was obvious in this chip – so it had certainly failed and probably made quite a loud pop when it did so. The chip was removed and a replacement taken from a Gondomania pcb soldered in – everything worked again.