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SectionZ
28th March 2008, 06:03 PM
This board was in poor condition on my scrap pile, it was thick with dust and had the writing ‘doesn’t work’. I suspected it was GunSmoke…

I cleaned it up a bit with a soft brush; I noticed it was missing a crystal and a volume pot.

I replaced the crystal 12MHz at K1 (as its marked on my board) on the top board ‘A’ and fired it up. The display was pretty much garbage but I could just make out the wanted posters, which confirmed it was GunSmoke and it was running.

I popped out the ROMs on the top board, there were no broken or bent pins, I cleaned the legs & reseated them, I replaced the volume pot also. To my great surprise it came up clean as a whistle and with sound! Except all character graphics were missing. :rolleyes

I then cleaned & reseated the ROMs on the ‘B’ board – No improvement. I suspected the RAM on this board, after piggybacking all the 2116-10s and a little more tinkering I spotted the 6148s and piggybacked the 6148 – 55 at C5, this brought up the character Graphics, but part of each graphic was still missing, replacing the 6148 at D6 brought up the rest but the colours were incorrect, the 6148 at G6 fixed half the colours & the one at C6 finally fixed all the Graphics.

In short, I removed, socketed and replaced the four 6148-55s on the bottom board.

Got a 100% Gunsmoke now :D not bad as I was about to start ripping parts off it!

Notes: The Dip numbers are reversed 8=1, 7=2 etc. There doesn’t seem to be any flip screen option.

Cheers, Sean.