Congo Bongo HS Kit    3-boardset Installation Guide

Step 0: Turn off power to the game

While it may be possible to install this kit without removing your board from its cabinet, you may find it easier to install the kit if you do remove the board. In that case, pay careful attention (or label), any wire connections as you disconnect your board so that you can correctly rehookup the game PCB afterwards. Take note of which side of the PCB edge connector is facing the parts side of the board and which side faces the solder side, This connector is typically not keyed and can be inadvertantly plugged in backwards - ouch! It is recommended that you label the connector faces with something like "parts side" or "solder side".

Step 1a: Locate the CPU/Controller board

This boardset consists of three boards (video, CPU/conroller, and sound). The CPU/Controller board is the larger pcb which is between the video and sound pcbs. It has 834-5166 on the PCB. It is the board with the edge connector for the main harness.
Congo Bongo CPU/Controller board (834-5166)

Step 1b: Locate the Sound board

The sound board is the smaller board on the top of the boardset. It has 834-5168 on it, and is also labelled "Tip Top - SOUND". It has a single gray ribbon cable connected to it and is attached with 4 or 5 plastic standoffs.
Congo Bongo Sound Boards (834-5168)

The sound board will need to be temporarily removed in order to expose the CPU Z80 processor such that the HS kit can be installed.

Congo Bongo Sound temporarily removed exposing Z80

Step 2: Remove the Z80-CPU chip

Locate and remove the Z80 chip on the CPU board. Use the above photos to assist in locating it. See Z80 Chip Identification for additional information. The Z80-CPU chip is a 40 pin (large) chip, located at U4 Do not get this chip confused with the other 40 pin chip nearby. Remove the chip gently by using a flat head screwdriver to pry it out of its socket from each end. Be careful not to bend any of the pins. If any pins do get inadvertantly bent, you will need to straighten them out before the next step. Needle nose pliers work the best for this.
Z80 Location Z80 Location
Congo Bongo Z80-CPU location

Step 3: Insert the Z80-CPU into the daughter card

Insert the just removed Z80-CPU chip into the empty 40 pin socket on the High Score Save Kit. Make sure pin-1 is correctly oriented. Pin-1 is marked on the Z80-CPU chip usually by some type of indentation or circle molded into the plastic. The end of the chip with the marking, needs to match up with the socket on the daughter card that also has a marking on the plastic. Pin-1 is also labelled on the kit pcb with a "1".
Pin-1 Identification
Click images for a larger view
Z80 CPU Chip
High Score Daughter Card
Pin-1 Identification

Step 5a: Insert the daughter card into the CPU board

Insert the daughter card back into the Z80-CPU socket on the CPU board where the Z80-CPU chip was originally removed from. Again, make sure pin-1 of the Z80/daughter card is oriented to correctly match pin-1 on the CPU board. Use the photos as a guide.

The header on the daughter board has pins that are more heavy duty than the original Z80-CPU pins, thus you will need to press very firmly to get the daughter card to be fully inserted into the original Z80-CPU socket.

Congo Bongo with HS kit installed

Step 5b: Secure the sound board to the CPU board

Unfornately once the HS kit is installed, there is not enough clearance between the sound board and the CPU board to use the same standoffs as before. You will need to figure out another way to securely attach the sound board to the cpu board. Possibly by using longer plastic standoffs or attaching the board in a different way such that it is not likeky to move around too much or cause any electrical shorts between them.
Not enough clearance to reuse the same standoffs

Step 6: Double check your work

Review the steps and double check that Z80-CPU is properly installed into the daughter card with no bent pins and that it is correctly oriented for pin-1. And that the daughter card is also installed snug into the Z80-CPU socket at U4 with pin-1 matched up.

Step 7: Powerup and game and enjoy!

Reinstall your board into the cabinet if necessary, and then powerup your game.

If the game does not come up, turn power off immediately, double check your work, and read over the trouble shooting section.

Step 8: Optionally remove the four CPU code eproms

The four CPU code eproms are not needed once this kit is installed because all of the software is contained on the single eprom as part of the kit. These four code eproms can be removed and used for other purposes. As well it saves a tiny amount of power and heat. This an an optional step and can be skipped.

CONGO CPU eproms CONGO CPU eproms removed
Congo Bongo CPU eproms can optionally be removed.