Taito – Rainbow Islands repair log

Hi there !

2 posts on the same day ? Watch out for hail 😀

A few years back I bought a Rainbow Islands pcb, the mythical Bubble Bobble sequel from Taito. I got it pretty cheaply then because of a very simple reason : the custom chip handling the colors (the infamous TC0070RGB) was in a very sorry state, and the game couldn’t run properly.

This custom chip is in a SIL package (Single In Line), soldered vertically to the pcb, making it really vulnerable to physical shocks.

The board was clean, but the custom was torn off and soldered back using component legs … as solder isn’t known for its mechanical strength, this repair couldn’t last.

Check it out  :


Unsoldered legs, loose connections, etc. … there’s a lot to do !

As I had various other ongoing projects at the time, and above all I didn’t know to tackle this issue I moved on something else and forgot this board in a cardboard.

A few months back I came across someone’s website offering print draft of this custom chip. They weren’t available online anymore due to some abuse, but after some time we came to an agreement and he provided me with the files in order to do some real testing.

I ordered 5 pcb pieces from PCBWay (minimum order), and started looking for the parts needed. The pcb uses CMS 0805 parts, I never had the chance to work on a project of that scale with parts that small.

Here are the pcbs from PCBWay (I removed the markings from the picture as I don’t want the person to be annoyed because of me 😉 )

Placing resistors before hot air soldering (it’s really small, magnifier recommended !)

Soldering done ! A bit of cleaning is needed, and I have to remove excess solder (hard to measure out with the needle), but it’s not that bad actually …

Added a socket a make testing easier.

Fresh new custom is plugged in, and …

Yikes … what’s happening ? Colors are there but seem washed out … looks like a grounding problem.

To be sure I rewired the original custom to the board, in order to rule out a pcb fault :

And everythings fine, so the problem is inside the new custom :/

After discussing back and forth with the designer, he detects a ground difference between 2 parts, and recommends me to add some kynar wire between 2 locations … I do as he says, and …

Great ! Quite happy to add this one to my collection 🙂

Cheers !