ZZZ

Zaccaria Puck Man Maintenance 2021

20/03/2022 - Missing up

Puck Man leaf switch

Pre-show testing encountered intermittent joystick up. Checking the joystick found a broken leaf switch cobbled onto the joystick. Replacement reproduction Wico leaf switches were ordered.

Puck Man leaf switch Puck Man leaf switch replaced

The reproduction Wico leaf switch was fitted and tested OK with a meter. Back in the cabinet the game directions all worked OK.

08/05/2022 - Open ground

Puck Man power transformer trapped wires Puck Man open ground

The original restoration didn't encounter ground issues but the coin door definitely felt a bit on the live side. Checking the ground found it open all the way through to the power transformer assembly. The transformer itself had pinched wires and the assembly was removed for repair revealing a missing bolt connecting through to the ground wire.

Puck Man power transformer Puck Man ground measurement

A simple reseating and re-bolting of the transformer fixed the open ground.

28/05/2022 - Puck Man game PCB #AA02895 repair

Puck Man game PCB on the bench

After an hour running on the bench the game was no longer running and didn't boot on power cycle. Testing with the Arduino ICT flagged RAM issues in one nibble:

Characters were also flickering on screen. A "RAM Write All Hi" or "RAM Write All Lo" didn't show any stuck bits on the scope. Using a video probe to compare IC 4K (2114) data bus with IC 4L (2114) found marginal signals on 4L. On the scope, 4L data bus showed bus intermittent half height signals on all four data bus lines and I suspected a bus collision. To try to locate which of the 3 ICs it was, a dab of freezer spray was used on each of the 3 in turn and IC 4L cleaned up the collision when cold. Removing 4L allowed the 4M and 4N RAM tests to pass and replacing IC 4L (2114) fixed the game.

Puckman Maintenance 2022

prswan@gmail.com