Tuesday 14 June 2016

Capcom System 1 (CPS1) Fitting a heatsink to the A01

By far the most common failure on CPS1 motherboards is the Capcom A01 custom chip followed by rams. Unlike rams the A01 cannot be easily replaced and can only be found on other CPS1 (and CPS2) motherboards.

To help try and get as much more life out of these chips as possible I decided to order some heatsinks and fit them to all my working boards (thanks to Winklepicker on J+ for the idea).

As you can see from this bad A01 I took a dremel to the die is quite small (1 cm x 1 cm).


I then went on RS looking for a suitable heatsink, there are 1 cm x 1 cm copper heatsinks on ebay sold for raspberry pi's but they would look a bit silly on a chip this size, they are also very short. It's my understanding that the bigger the better when it comes to heatsinks as they disperse heat better.

So I ended up ordering one of these http://uk.rs-online.com/web/p/heatsinks/7500885/ which covers the majority of the chip without blocking access to the pins (they may need reflowing in future) and is tall but not too tall to hit the B board that plugs in above it.


The sticky backing these heatsinks came with is pretty poor so I removed it and instead used Phobya which is a 2 part thermal compound you mix and it dries like glue. I already had this on hand from fitting heatsinks to ULA (zx spectrum) and SID (c64) chips in the past.



The finished result (yes I need to clean that flux up).