Super Buster Bros Repair Logs
Repairer: channelmaniac
Symptom: Dead. Solid white screen
This board uses the Kabuki CPU, a modified Z80 with a decode table kept in internal RAM. If the battery dies, the board will suicide.
Revived the board by removing R33 and jumpering the right side pad from R33 to ground to make the Kabuki act like a standard Z80. Replaced the ROMs at 11H, 13H, and 14H with ones programmed with suicide free code. Jumpered pin 30 on each 27C020 and pin 1 on the 27C512 replacement ROMs to pin 27 of the Kabuki CPU to finish the repair.
Suicide free code and instructions are both available off the Dead Battery Society website.
Symptom: Dead
This game had the same problem of a dead suicide battery. It needed new ROMs programmed and a slight reconfiguration to make the Kabuki CPU act like a normal Z80.
On these games, the first thing to test is the NiCD battery. If it's low then the game will have suicided. There's no way to reprogram the codes into the Kabuki so using the "Phoenix" code and board modifications listed at the Dead Battery Society website is the only way to bring these pre-CPS1 suicided games back to life.
Be sure to remove the battery to keep it from leaking on the board. Many of these old batteries will have started leaking. This is evidenced by a blue or blue-green crystalline growth on the ends of the battery. In bad cases it will creep along the traces and corrode them and any components it comes into contact with.
Symptom: Dead - Suicided
Removed 1 resistor and jumpered one pin to ground on the Kabuki CPU. Programmed 2 2Mb EPROMs and 1 512K EPROM with Phoenixed code. Jumpered pin 1 of the 512K EPROM to pin 30 on both 2Mb EPROMs and to pin 27 of the Kabuki CPU. Tested board.
Symptom: Dead
Someone attempted to phoenix the board incorrectly. It had a Z80B Processor instead of the Kabuki, but they did not remove R33. Removed R33, installed missing EPROMs for 11H, 13H, and 14H with ones programmed with the phoenix code. Jumpered one bad trace, reset the NVRAM, and tested.
Symptom: Dead
Someone attempted to phoenix the board incorrectly. It was missing the Kabuki CPU, they did not remove R33, and they installed 27C040 EPROMs with pin 31 removed instead of the 27C020 EPROMs for 13H and 14H. Removed R33, installed the correct 27C020 EPROMs for 11H and 13H. Erased and reprogrammed the 27C512 at 14H with the phoenix code. Reset the NVRAM and tested.
When using 27C040 EPROMs instead of the 27C020 the code must be loaded into the upper half of the EPROM as pin 31 (A18) is tied high by the game board. Leaving it floating leads to game crashing as the state of the pin cannot be guaranteed. To use the lower half of the EPROM pin 31 must be lifted out of the socket and tied to ground with a jumper wire.
Game: Super Pang Symptom: Dead. Solid white screen
Like Super Buster Bros., this board uses the Kabuki CPU, a modified Z80 with a decode table kept in internal RAM. If the battery dies, the board will suicide.
Revived the board by removing R33 and jumpering the right side pad from R33 to ground to make the Kabuki act like a standard Z80. Replaced the ROMs at 11H, 13H, and 14H with ones programmed with suicide free code. Jumpered pin 30 on each 27C020 and pin 1 on the 27C512 replacement ROMs to pin 27 of the Kabuki CPU. Removed the battery to finish the repair.
Suicide free code and instructions are both available off the Dead Battery Society website.
Repairer: Apocalypse
Source: Super Pang - Mitchell/Capcom 1990 (repair log)
This game is equipped with a suicide battery that holds the encryption keys of the Kabuki CPU (a modified version of the Z80). The latter was still the original one and was completely flat (0.0V).
FYI when this games commits suicide it only displays a static blue screen.
So, I followed the procedure described on "The Dead Battery Society" webpage.
Long story short, this mod allows the Kabuki to work as a standard Z80 CPU with decrypted ROMs.<br.
3 ROMs have to be replaced and a simple wiring hack has to be done (as the decrypted ROMs are twice as big as the OG ones).
This brought the game back to life. Only to notice that sprites were severely corrupted:
This is due to a bad custom chip noted 86S105. Unfortunately I don't have any scrap board that could be a good donor... If you have a spare chip just leave me a comment.