Repair Logs

Donkey Kong (Nintendo) PCB repairs

12/06/1999

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.

12/13/1999

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

09/20/2001

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.

03/13/2002

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.

04/25/2002

Problem: No digital sounds

Solution: Broken 10K pot at VR1

06/17/2002

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

09/10/2002

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.

09/10/2002

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.

04/01/2003

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

04/20/2004

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

04/20/2004

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

11/21/2004

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.

05/15/2015

Problem: Sprites appear to walk behind invisible vertical slats

I used the bugtrap for this one, I suspected the LS157's on the bottom of the video board, and one at 7S shows a non-matching output. Replacing the faulty chip did not fix the problem. Next I looked at the LS283 ADDR chips and jumpered a good chip on the one at 8R and the screen cleared up. Replacing the LS283 at 8R on the video board fixed the baord.

Solution: Bad ADDR 74LS283 at 8R

05/19/2015

Problem: Flat walk sound - TKG4-11-CPU

Ok, I'm working on a Donkey Kong board for a fellow KLOV'r and he points out the walk sound is 'flat', no pitch change at all. I can verify this is by shorting the base and collector (Pins 2 and 3) of Q6 to turn on the raw sound. The sound was a steady pitch, no oscillation at all...

I told the board owner, it was normal on all TKG4-11-CPU's to have this same flat walk sound. After a bit of a protest and pointing to folks pointing to my repair logs, I agreed to look it over again and see if it was indeed just something that TKG4-11-CPU owners had to live with.

Anyway, I spent yesterday afternoon testing resisters, replacing the two chips (4049 and 556 timer), and all caps in that circuit, including the big green guys. Surely after replacing or testing every component in that circuit, I had to have nail it, but NO CHANGE! Still that dang flat walk sound.

So.... just for fun I start following traces and matching them to the schematics I have, TRS, TKG4-13 and 14. It turns out that the little circuit with the two inverters from the 4049 are backwards on the board. Hmm. R48 runs to pin 12 of the 4049, and C30 connects to pin 9, which is backwards from all the schematics, but reversing them seemed has no effect. Back to square 1....

This morning, remembering what I had told the board owner at first (All TKG4-11's sound like this) I start gathering up my different version of CPU boards and checking the sound output for walk... Well, what do you know.. all 6 of the TKG4-11-CPU's have a flat walk sound, as I previously thought, but all the other CPU's have the normal 'warble'.

It has just got to be those two swapped pins in the 4049 circuit. Otherwise why would they change it in future revisions and why was it different on the 4 board sets? So, I cut two traces and jumpered the circuit to match the schematics and.... lo and behold... warble!!! I must have missed something by not cutting traces the first time.

Solution: So, the fix for the TKG4-11-CPU flat walk sound is...
Cut trace from pin 12 of the 4049 at 8L to the 4.7K resistor R48 (cut the trace on top of the board between R47 and R48) and jumper the loose end of R48 to pin 9 on the 4049 at 8L. Then cut the trace between pin 9 on the 4049 at 8L and the - (negative) side of C30 (on the bottom of the board), then jumper the - side of C30 to pin 12 of the 4049. Done! I did both the jumpers on the bottom of the board.

04/12/2017

Problem: Missing Sprites

Tools: Logic Probe and BugTrap 1674

Pin 13 of the 82s09 ram was stuck high. Traced it back to a bad LS161 at 5K. Verified LS161 was bad with the BugTrap 1674 chip comparator. Replacing that chip restored the sprites.

Solution: Bad LS161 at 5K