Aug 032018

Yet another Truxton II PCB (overseas release of Tatsuin Oh) on the bench and always from Portugal :

The board was stuck on boot on a colored striped static screen :

Main 68000 CPU was not running, both data/address bus were inactive.For first I checked the ‘GP9001’ custom GFX controller¬† (QFP 208 pin ) which is a common issue on hardware that use it:

I found some lifted pins:

Reflowing them didn’t lead to any improvement.The board uses the ‘infamous’ custom ‘HK-1000’ custom (the early fragile ceramic revision) which handes inputs :

A closer inspection revealed the IC was damaged, some pins were broken at package insertion so beyond repair:

As said, the ‘HK-1000’ handles inputs but a faulty one can prevent the game to boot because some CPU address lines are used to generate the enable signals for it.I removed it:

Without the custom the board successfully booted up but obviously game was not playable due not working controls:

So I installed two strips of 2.54mm female machined pin headers in order to host a reproduction of mine:

The last issue I had to fix was some rustling background noise:

With the help of my audio probe I quickly figured out the sound was clean before reaching the 2.2K sound potentiometer :

I replaced it and this restored a clear sound.As ‘icing on the cake’ I removed an ugly hack to use a quartz instead of an oscillator and installed¬† the proper part:

Yes, yet another Truxton II PCB fixed!


 Posted by at 10:46 pm

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