Donkey Kong (Nintendo) PCB repairs
Problem: No pounding sound from Kong
Missing only Kong sounds when he
jumps on and breaks the girders in the introduction and no sound when
he pounds on the girders.
Tools: soldering iron
First, I cleaned and re-seated all the eproms and the 8039, no change.
I replaced C24 elec. cap, as it was corroded leg was falling off,
still no Kong pounding sound. Then reheated the solder on all the
caps and transistors around the area of C22 and the ones around two
sound eproms. Viola! It worked. Now, if I could only figure out
which cap did the trick. It's nice to hear Kong again.
Solution: reflow the solder on the caps in the sound circuit.
Problem: loud hum sound at all volume levels
The Sanyo monitor has a small audio amplifier board on it, I
swapped the board with another one and the hum disappeared. Looking closer
at the board I bent back the electrolytic capacitor at C387 and the leg came off
in my hand. I replaced the cap and reflowed the solder on the other electrolytic
capacitors and re-installed the board. When I powered up the game,
the hum was gone.
Solution: replace bad electrolytic capacitor and reflow the solder joints
on the monitor's sound amplifier board
Problem: missing grin sound during into
I don't know what else to call this sound, but after Kong
climbs the girders and stomps on them to break them all, he grins and you
hear a kind of heee, heee, heee sound. Anyway, it's a digital sound. To
make a long story short, I finally changed the sound EPROM at 3F and that
fixed the problem, Kong is now grinning away and you can hear him again.
Solution: replace bad EPROM at 3F on the CPU board.
Problem: Missing sprites
There were NO moving sprites on this board at all. The ladder
at the beginning would move up and when Kong pounded on the girders they would
break, but Kong, Mario, the barrels and everything else that moved was missing
Solution: Replaced bad MC10125 at 1H on the Video board.
Problem: No digital sounds
Solution: Broken 10K pot at VR1
Problem: TKG3 board set - Board will not sync
I replaced the pots and no change. All the LS161/163s were pulsing.
Looking at the schematics, there is a 74LS02 connected to the VBLK/CMPBLK outputs.
I noticed that if I shorted pins 2 and 3 on the LS02, the picture would semi-straighten
up. Replacing the chip fixed the board.
Solution: 74LS02 at 1C on the CLK board at 1C
Problem: Missing all motion sprites
All sprites were missing, the I finally traced from that data lines
back to see where a chip had died. When I got to the LS237 at 6J, it was dead. Probing the clock line, I found
there was no clock on pin 1. The clock comes from pin 10 of the LS139 at 5F. Pins 13 and 14 had input on that
chip, but there was no output on pin 10. Replacing the chip fixed the board.
Solution: Bad LS139 at 5F on the video board.
Problem: Very low sound output for digital sound.
I first put in a new 8035 and both sound roms, 3F & 3H. No change.
Looking at the output of the 8035 with my logic probe, I could see that there was data. Next, I checked the
inputs of the DAC08 when music is playing during game play. Data here too. Looking at the output of the DAC08
at pin 4 showed that is seemed to be working fine also. Next on to the MB8314 (LM324) at 7K. The input on pin
13 from the DAC08 was fine, but the output on 14 seemed to remain low with my probe. Replacing the LM324 fixed
the sound problem.
Solution: Replaced bad LM324 at 7K on the CPU board.
Problem: Sparklies on Kong's lower lip when he grins and on the barrels in the top-left section
of the first level.
Solution: Bad 73LS163 at 3E on the video board
Problem: Background tone always present, walk sound off.
Sounds like the walk sound never completely cuts off.
Solution: replace transistor Q6 on the CPU board, a 2SC 1815
Problem: Whirring sound all the time.
Sounds like the jump sound never completely cuts off.
Solution: replace transistor Q4 on the CPU board, a 2SC 1815
Problem: Picture takes several seconds to sync, and
characters are broken
up in slivers, sections are up or down from where they should be.
Normally this is a 74LS163 at either 3E of 4E on the video board, but
replacing both of these chips did not change the problem. I noticed if I press on the section of the board with
these chips, the picture would somewhat fix itself. Running my fingers on the bottom of the MC10105 at 1F on the
video board would really mess up the characters even more than they were. Replacing the chip fixed both the slow
sync up and the characters.
Solution: Replaced faulty MC10105 at 1F on the video board.
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