Apr 132018
 

Received from France this mint Xexex PCB:

The board was bought from Japan as working but when arrived there was a noticeable sound issue, a loud buzzing noise present also at lowest volume level :

Obviously the culprit was the ‘054544’ audio module.Electrolytic capacitors on it were already replaced but this was not enough :

Most likely the probem was on the underneath of the module so I removed it and installed sockets:

There was some corrosion on underneath but nothing really serious:

I decided to test the module on an X-Men PCB and it worked fine, audio was clean:

The technical reason why it worked  is that X-Men doesn’t use the pre-amplification circuit of the module (a LM358 OP-AMP is present externally on PCB) while Xexex does.So the problem was the 4558 OP-AMP on underneath of the module.I removed it and replaced with an LM358:

The buzzing noise was cut out:

Lastly I painted the module to finish the job:

 Posted by at 4:26 pm
Apr 102018
 

My beloved original pcb developed once again problems after the last repair log you can read here:

Psychic 5 repair log

This time, the overall colour palette was pinked and all text was missing

After some troubleshooting I found again a problem with a Fujitsu ttl 74ls08, same type and week/year of manufacturing of the one I changed on the old repair log!

 

After changing it, the game worked fine for some minutes and then it developed a new problem

 

Game lost sync and became bluish

Again I decided to concentrate on the only Fujitsu  74ls08 ttls which were present on the board until I found the faulty one.

Same week/year of manufacturing and same fault: dead outputs

In addition, I found another couple of Fujitsu 74ls08 which had dead outputs  and I decided to change all of them with good ones.

Now the game is 100% fixed but there are 3 more Fujitsu ttl waiting to be replaced. I ran out of parts otherwise I would have changed them immediately.

Apr 082018
 

Muddymusic sent me a Chopper I PCB to look at.
There were 5 PAL’s on this board and all were soldered in so I had to desolder them to dump.
All the PAL’s were unlocked so these are native dumps in their native format.
They will need converted to GAL format to use in a GAL chip.

 Posted by at 2:58 pm
Apr 022018
 

Today an important addition to our PLD database thanks to ‘coolmod’, one of our finest contributors.We have from him PAL dumps of :

  • Night Striker

This is a quite rare board, a 3D shoot ’em up  developed and published by Taito for the Taito Z System in 1989.Board uses a lot of PLDs and some of them are present multiple times at different location.We have the complete PAL dump set (from PAL20L8/PAL20R8 and PLHS18P8 devices, as natrive dumps and 256KB binary respectively) and but for now only some have been reversed and successfully tested into GAL targeting device.

  • Jackie Chan

A 1995 fighting arcade game with renderized characters developed and published by Kaneko.Two ispLSI 2032A (PLCC44 package) PLDs dumped.Dumps are unested so for now we consider them as “assumed working” (as well as the all the other ones we had from this PCB) since devices were unsecured but we are looking for someone to test them back on PCB.

Thanks again to ‘coolmod’ for his contribution.

 Posted by at 6:01 pm