ZZZ

Zaccaria Money Money Maintenance 2023

08/04/2024 - Game PCB 001/002 repair

Money Money game PCB on the bench Socket pin damage on IC removal EPROM socket replacement

Pre-show testing found that the game reset in attract mode and flexing of the ROM PCB suggested bad IC sockets. All of the program ROM sockets and security PAL socket were replaced that fixed the game reset fault, however sound wasn't working properly.

Money Money game PCB on the bench

After a few minutes of run time the music stopped playing and other game sounds cut in and out. Cross swapping the two AY-3-8910 and the 6821/6802 from the sound/speech side didn't change the behavior. The speech CPU is master for sound - IC 2E (LS244) receives the main CPU sound command and IC 2G (LS374) is the output latch for the music command. The command interrupt was present on IC 1L (6802) pin 4. Intermittency of the sound was observed on IC 2F pin 11 (CSDIA) for the coin credit sample playback.

Money Money game PCB with Arduino ICT on the sound 6802

Support for the Money Money sound/speech CPU was added to the Arduino 6802 ICT. Observing the sound commands found:

A basic 0x00,0xFF read/write check of the 6821 was OK and a basic 0x00,0xFF write to the 1408 DAC resulted in a "thump" sound. Writes to the music port of 0x00,0x55,0xAA,0xFF had no effect (no music played) but I didn't know the correct music command codes. Observing the ROM data & address bus during coin credit playback found the access pattern change last as long as the coin credit sound should have lasted but IC 2F pin 11 CSDIA signal was intermittent consistent with the intermittent sound output. Checking IC 5E found:
I suspected IC 5E (LS32) was bad and replacing it fixed the intermittent game sounds but there was still no music.

Checking the music CPU with a scope found pin 29 D4 a mess where the socket pin was OK but the CPU pin was bad. Pin 29 was found to be corroded at the bottom but all other pins looked OK. The pin was cleaned but music was still unreliable. The CPU swapped but the music was again still unreliable. Looking at the CPU data bus pins during music found the pattern change in line with the music playback fading out. The music clock at IC 4G (AY-3-8910) pin 22 CKGI was idle low. Working back to IC 5F (4040) found:

Since IC 5F was free running I suspected it was bad. After a power cycle, pin 9 had a sawtooth clock present but then for unknown reasons became fuzzy and faded to idle low matching the loss of music. This was repeatable - the signal was present after a power cycle but then faded away a few seconds into music playback. Freezer spray on IC 4F had no effect. After IC 4F (4040) was replaced, music played without issue and the signal looked OK on the scope (4.9V hi and 0V lo with 10x probe).



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