Yesterday ‘Bad_Ad84’ sent in a dump from the PAL present on a Nintendo M82.For the uninitiated Nintendo M82 is a demonstration unit for the Nintendo Entertainment System.
Original dump came from an unprotected PAL16L8 and was converted by me into GAL16V8 targeting device.The original dump has been confirmed as working by its submitter while GAL replacement needs to be tested yet.Thank you again, guy, for your submission!
Here are the dumps from the two PAL present on a Silent Dragon original PCB.Both dumps are tested and working in a GAL16V8 targeting device.
I got two Silent Dragon PCBs recently.I never heard about this beat ’em up manufactured by Taito and a quick look at MAME lead me to try a first repair of this cool game.
Board was in quite good shape (a little bit dusty though..)
When powered it on I got a steady black screen but I could hear all the sounds and also put credits in.So I started to press and flex the board and all the graphics were restored on screen when I touched the area around the TC0180VCU ASIC.So I decided to reflow the ASIC (some pins were really lifted) which ,according to MAME source, controls the video and decode graphics:
I was quite sure that I succeeded but I was wrong since the board still played blind.Crearly there was a loose contact somewhere so I started my visual investigation on solderside.There were no broken traces but I came across this:
Two pins made contact between them and precisely the VCC pin of a 74LS245 @IC26 and pin 1 (input) of a 74LS04 @IC27.Pin 2 (output) of this 74LS04 was connected to /OE pin of the four GFX MASK ROMs and this explained why there were no graphics at all.After removing the short,I finally could enjoy also with my eyes this game.
Now time to dump the two PALs on it! 🙂
After the repair I decided to dump the PAL on this PCB.There where four PAL, I could dump and reverse only three of them since there is one registered device (a PAL16R8).All dumps are tested and working in a GAL16V8 except for the one marked ‘TS-002’ for which I had to use a GAL18V10 as targeting device.
My friend Silvio kindly donated me a couple of faulty boards, this ‘Captain America and the Avengers’ was one of them:
I was expecting some boot troubles but when I fired up it I got this:
All was OK except for sprites that were all missing.Since I already worked in the past on similar Data East hardware I knew that sprites are generated by some ASIC, in particular the one marked ‘DATA EAST 52’:
Infact, when I firmly pressed this ASIC, sprites were restored.Proving the tightness of the individual pins with a needle as I usually do confirmed that some pins were lifted.So time was to do a reflow of this chip and this was enough to fix the board completely.
Thanks again, Silvio!