Friday, 17 July 2015

Some arcade board fix: Zero Wing and STV motherboard

 I received the board as part of my haul and it booted up with proper game-play and music, however, the graphics were wrong or missing. Rather than tossing it aside and moving to the next board, I decided to troubleshoot it. When the board is placed on the vertical orientation, the game will not boot and instead comes up with a "object ram error" or sometimes "video ram error". I firstly checked the pins on solder side of the board to make sure nothing is touching together and manage to find a couple of dry solder joints which I touched up.

Still getting the error after the initial touch ups so I proceeded to look at the custom chips. Nothing looked out of the ordinary, but I notice that a slight pressure on two of the chips yielded perfect graphics and game-play. This lead me to up-skill in the smd way of soldering specifically re-flowing those damn custom chips.

These are the two troublesome chips:

1. The BCU-2 and
2. the custom chip on the "F" position of the board.

So I proceeded to re-flow them with great success! As I was greeted with perfect gameplay.

I finally cleaned up the residual lacquer and sprayed on a new coat to extend the life of the board.

The STV board also had a know SH2 processor malfunction as pressure is required on the chip to allow games to boot up properly or it will error out. It is the big square one on the edge of the board.

So I applied my newly acquired skill (plus a little bit of wick work to get rid of bridges) and presto!

VF1.5 15.6(?)Khz version.