PCB Repair Logs Frog
Frog
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|
| PCB Image | Frog |
|---|---|
| Pin Out | Reserved |
Repairer: Arcade King
Forum Thread: Frog PCB Repair
Won this one a few weeks back.
Problem: Garbage on the screen, frogs visible and game seems to be playing
Fix: Bad 2114 ram at IC86
Problem: Board decided to die
Fix: 74LS368 at IC73
Problem: Colour of Frog wrong. Frog would have white in the center instead of yellow and showed up red at the bottom of the screen when demo on, some text was also wrong colour.
Fix: There is a hack to correct colours on this board. Pin 15 of the 74LS377(IC61) was connected to pin 4 of a 74LS20(IC36). Moving the wire to pin 5 of the 74LS20 fixed the colours on the frog.
Problem: No sound
Fixed: z80 on sound board
Problem: Background colours were wrong, top colour was a a royal blue while the bottom was a navy blue which is what the top was suppose to be.
Fix: From playing around with the Scamble to Frogger hack I learned the background colours went through a 74ls08. shorting inputs at 4 and 5 would make the entire screen navy blue while leaving the output ping 6 out would fix it entirly. Shorting the two inputs were not a option for me so i traced everything back to a 74126. To cut a long story short there are 2 470 ohm resistors 1 above and below this 74126 chip both dictating the final colour of the background. Removing the resistor at the top fixed the colours. Both resistors look like they have been replaced.
If Klov is anything to go by FROG was a bootleg Frogger with modified colours. This board would appear to look the same as the Konami/Sega one but wont run the programs.
There was some wiring done (poorly) to a 74ls377 I now know was done to correct the colours back to how Frogger looks.
Very happy with this board, be nice if I could make it say Frogger on the title screen. Any programmers in our little group feel like some hacking?
