Asteroids Arcade Machine Repair Log 07/02/2010

Symptom: Screen Dark

Cause: Contrast control phsically broken
Fix: Replaced Contrast control Variable Resistor on monitor PCB
Fix 2: Focus Connection of High Voltage PCB bad connection - Resoldered Odd Screen Image

Symptom: Asteroids PCB Dead

Cause: Physical Damage
Fix:
- Broken CPU Holder - Replaced
- Broken EPROM Holder - Replaced
- Missing EPROM - New one written and put into machine
- Broken Switches - Replaced
- Missing Crystal - Replaced
- Missing Reset Switch - Replaced
- Broken PCB Traces - Bridged with small bits of wire Broken CPU and EPROM

Symptom: Game seems to work but 1/2 of the screen is missing

Cause: Poor X-Y connection on Monitor PCB
Fix: Resoldered connection onto monitor PCB
Info: These problems seem fairly common and are caused by the screen being effectively 4 separate systems one for the positive and one for the negative in the x and y directions. These is quite good as it means it is alot easier to diagnose problems as one of them should work!

Symptom: Game seems to work but monitor intermitantly dims / fades

Cause: Filament voltage not always present Monitor Tube can be seen going dark
Fix: Resoldered connection onto monitor PCB

Symptom: Game seems to work but has issues!

Symtoms: Random explosions saucers and space craft.
Cause: Memory Test fails indicating Memory Problem
Fix: Socketed memory chips and replaced top left memory chips. Memory Corruption messing up gameplay.

Symptom: Game works some controls not functioning

Cause: switches are a bit dodgy
Fix: Put paper in each switch and pulled out cleaning contacts Gaining Access to the controls

Symptom: Game sometimes drops out

Cause: Poor connection between wiring harness and PCB
Fix: Tried cleaning PCB connections then gave up and Tinned PCB connections

Before Tinning Asteroids PCB Connector Edge Connector Before Cleaning