Bringing back DK JR from the dead

hindered

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I bought a DK JR board that was non-working. Here's what I've done to it so far.

-Replaced the missing z80.
-Verified the VIDEO board is 100% functional and good by attaching it to my working CPU (including ribbon connectors and rainbow cable) -- all problems are most likely related to the CPU board.
-Used my braze HSS kit to find and replace a couple of bad ram on the CPU board.
-Replaced the chip at 7k on the CPU board.
-Verified the chip at 7h CPU is good by testing it in my good JR board.
-Dumped and verified that all ROMs are good using mame/romident.

The board is being tested in my DK JR cocktail, which plays my DK JR, DK and Mario Bros pcbs flawlessly. However, this board still has the following issues:

Issue 1: The colors are weird and there are huge blue areas intermittently on the screen. I'll try to get a picture of this issue later to better explain. This COULD possibly be a monitor adjustment issue, but as I said, my other DK/JR/Mario boards display great without adjustments.

Issue 2: No intro music, no background music. Replaced 7k, verified 7h, no change. Haven't yet replaced 8k, C24, C25 as recommended on Mikesarcade/brasington.

Issue 3: Jump sound sounds REALLY weird. Crash sound missing. No walk sound.

Issue 4: Image displays upside down. My Good DK and JR boards display properly in the cocktail, right side up to the Player 1 side. The bad one is upside down, so when the game starts, it is right side up for the Player 2 side. No clue where to start with this one.

Anyone have any suggestions?

EDITED to add: The board behaves the same with/without the HSS kit attached.
EDITED again for clarity.
 
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Issue 1: The colors are weird and there are huge blue areas intermittently on the screen. I'll try to get a picture of this issue later to better explain. This COULD possibly be a monitor adjustment issue, but as I said, my other DK/JR/Mario boards display great without adjustments.

Try tapping on the pots on the game board. Could have a bad one, or a bad connection.

Issue 2: No intro music, no background music. Replaced 7k, verified 7h, no change. Haven't yet replaced 8k, C24, C25 as recommended on Mikesarcade/brasington.

Issue 3: Jump sound sounds REALLY weird. Crash sound missing. No walk sound.

I had similar problems on a DK Jr. I worked on. Turned out to be the socket on one of the large 40 pin chips. Cleaning the legs and reseating it fixed the problems.

Issue 4: Image displays upside down. No clue where to start with this one.

Is it in cocktail mode? Check switch H. Could be dirty too.

-Ian
 
Try tapping on the pots on the game board. Could have a bad one, or a bad connection.

Not sure what pots you mean, unless you mean the ones which control x/y position, which are fine.

I had similar problems on a DK Jr. I worked on. Turned out to be the socket on one of the large 40 pin chips. Cleaning the legs and reseating it fixed the problems.

The chip in 7H is fine and clean, as is the Z80. Could be the 7H socket, I suppose. I didn't reseat the third large chip, which I don't think has anything to do with the sound, although I should reseat/check it out anyway.

Is it in cocktail mode? Check switch H. Could be dirty too.

The board behaves the same whether in cocktail or upright mode. "Up" and "down" are flipped on this board vs my other Nintendo boards.
 
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Not sure what pots you mean, unless you mean the ones which control x/y position, which are fine.
Ack. Thinko. Was thinking about the inverter board (has level controls for each color). Last Nintendo game I worked on had one mounted inside the cabinet.

The chip in 7H is fine and clean, as is the Z80. Could be the 7H socket, I suppose. I didn't reseat the third large chip, which I don't think has anything to do with the sound, although I should reseat/check it out anyway.

I remember having very similar problems and cleaning/reseating a chip. Unfortunately, it was rather a long time ago, and I don't remember which one :)

The board behaves the same whether in cocktail or upright mode. Even if it were in cocktail mode, since I'm testing it in a cocktail table, "up" and "down" are flipped on this board vs my other Nintendo boards.

Weird.

I'll have to look at the schematics for the board again. It's been a while since I worked on one.

-Ian
 
Sounds like you're on the right track.

Relevant highlights from Braze suggest 8K to get your digital sounds back.

Looks like your jump is C24 or C23 for the jump (which doesn't help your digital situation).

I'm just posting the stuff from Braze for reference. Keep us posted.

-There are 5 analog sounds with DKjr can produce. Each with its own (sometimes shared) separate circuit. Any one of these can easily fail independently.

Walk
Climb
Jump
Fall
Crash

-Walk and Climb share much of the same circuit and only the pitch is different. Lower for walk, higher pitched for climb.

-Jump sound shares some common circitry with Walk and Climb above.

-All of the other sounds, spin, credit, die, and music are generated digitally by the 8035 MPU. Typically these sounds either all work, or all fail.

-Jump sound was incorrect. Same capacitor C24 (47uf) again. Also, bad C23 (47uf) can cause a incorrect jump sound.

-No Walk (Left/Right) sound. Chip 6L (4020) bad.

-No long fall sound. C37 (0.12uf) broken.

-No digital sounds at all. Chip 7K (LM324) bad.

-No digital sounds at all. Both Chip 7K (LM324) and Chip 8K (DAC-08) bad. It is not very common for the DAC to fail.


The upside down position would lead me to believe it was the cocktail dip switch too, but you're using a cocktail right?
 
Re: Issue 4:

Found this page on Braze's site. I'll check to see if this hack has been completed tonight.

http://www.brasington.org/arcade/tech/flip/dkj.shtml

Braze said:
In the corner of the CPU board and nearest to the white power interconnect connector locate a yellow rectangle with some solder pads.

Look for the text SL6 and CL9

In its factory state, the pad at SL6 will be OPEN (not connected), and the pad at CL9 will be CLOSED (shorted).

To flip the screen, these need to be reversed. That is, CLOSE SL6 and OPEN CL9.

You can close (short) SL6 by just applying a large solder blob to the pad. You can open (cut) CL9 with a sharp exacto knife.

Thats it, next time you powerup your screen should be flipped!
 
The hack has not been done, and the screen ALWAYS faces player 2, even if in cocktail mode and in a two player game, both player 1 and player 2 are "upside down" from the POV of player 1.

Replaced 8k with a DAC08 from a DK parts board I have, and replaced C24 with a new 47uf cap, no change.

Cleaned and reseated the two proms on the CPU board and the blue lines/bleeding went away, although there are still color and sprite issues.

Here's a video: http://www.youtube.com/watch?v=7BlGJY5ZX2s
 
Did some more testing since my last post and cleaning the PROMs doesn't seem to have made the blue line go away completely, and maybe someone looking at the video can verify, but it seems like the water does not extend down as much as it should... anyone agree?
 
You could use MAME for a comparisson on the video. It's hard to see on your video.

I'm just brain storming on the sound but, being that walk, climb, and jump are all the same sound (just pitched differently), maybe its the pitch modulating circuitry that has failed. 6L or 6K might be a culprit there (from looking at the schematics all of the the analog chips run through 6L, 6K, and 5K.)
 
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