Saturday, 22 June 2013

Double Dragon - Repair Log - Day 1

Double Dragon - Repair Log - Day 1

Today Beap's Double-Dragon board that came out to play..

Some repair work had previously been carried out on this board, and it looked like Ram & sound substitutions primarily.. The CPU had also been replaced.

But on power up there was an unnerving buzz for two seconds and blocks of corrupt data in a static pattern across the screen. :(

First I had to remove some rust from the sound side of the board..

And there was a region of the board where a 5-pin-resistor-pack had been previously removed..

Cleaned the rust & crusty flux & ordered some parts..

Will have to completely rebuild the tracks - this damage shouldn't stop the board from booting - but I won't expect the sound to function too well until it is resolved.

And from below:

Also removed a big metal pin that was shorting a transistor:

The soldering around the previous repairs didn't look too healty, lots of dry flux, a couple of shorted traces and maybe even a split track or two. :/

Cleaned it all up a bit.. reflowed the solder - removed all the shorts, and attempted a power test..

It' booted! - Not without issue though.. but its playing and makes a few sound effects on start-up!

Some progess at least.

The sprites & BG-layers looked to be functioning.. looks like the Font layer is glitched - will have to probe those Ram chips, to see if they have to be replaced.

To be continued...