Welcome to a new contributor, Corrado.
Another source of repair logs and general tech info is always good.
Jan 092015
Taito F3 D77-03 added
PAL Updates
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Jan 072015
muddymusic dumped a D77-03 PAL from one of his Taito F3 cartridges today.
At this moment it is untested so if you test it please let us know.
Thanks to muddymusic
Lightning Fighters repair log #2
PCB Repair Logs, Repair Logs
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Jan 062015
Found this Konami Lightning Fighters PCB buried somewhere in the pile so today I decided to take a look at.
I know quite well this kind of hardware since I repaired two of them in the past and I can say it’s not really complicated, the use of graphical ASICs simplify a lot the PCB layout and troubleshooting.
Once powered on I got a solid black screen.Probing the main 68000 CPU revealed that watchdog was active and board was resetting endless.Dumped the two program ROMs gave me bad dump of the one @E15.Once reprogrammed a 27C010 EPROM, board succesfully booted but all colors were clearly wrong:
Schematics of this game were available so looking at them revealed that color RAMs were two 2018 @D18 and D19.Probing these two static RAMs I found some addressing lines not pulsing fine.All of these were tied to the four outputs of a 74LS157 @F19 (whose inputs were connected to address lines of 68000 CPU and ASIC marked ‘053251’ so this was how the two colors RAM were being addressed) .
Piggybacking a good 74LS157 restored all colors.Using my HP10529A logic comparator was a further proof of my suspects that were confirmed definitively testing this multiplexer out-of-circuit where it failed miserably:
Fitted a good 74LS157 brought back the PCB to 100%.
SEGA NAOMI multi BIOS
General
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Jan 042015
P1pkin has released his NAOMI/NAOMI2 multi BIOS for everyone.
By changing the dipswitches you can change the region of your system
DSW2 DSW3
OFF OFF Japan
ON OFF USA
OFF ON Export
ON ON Korea
Original thread can be found here
Thanks very much to P1pkin for this.
ABI Chipmaster Pro – FAIL!
General
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Jan 022015
Here is a sad fact and its one I picked up on quite a while ago when I compared the Chipmaster Pro to my Boardmaster 4000.
Both of these devices test the Z80 CPU out of circuit yet the Chipmaster Pro seldom gives a PASS result where as the Boardmaster always gave me a true PASS or FAIL result.
I bring this up now as Andrew96 reminded me of this issue and has even made a short video of it here
https://www.youtube.com/watch?v=GCA_KPoa18I&feature=youtu.be
As he states, ABI refuse to fix this problem and that is just unacceptable.
Be warned before you shell out a good amount of cash on one of these devices. You can’t even add your own test without spending another load of cash on the extra software.
Im glad I never paid much for mine.