Never leave a locked-up game switched on
When the CPU locks up the lamp matrix stops strobing and the lamps get the full 18 V. That burns out bulbs and can overheat the driver board badly enough to desolder parts. Switch a locked-up game off straight away.
Overheating driver board parts can burn; switch off a locked game at once.
Systems
Related tips
- A whole lamp row or column dead or stuck on
- Match and player lamps light at random in play: faulty replacement driver board
- GI in at the power supply but not out: check the GI relay
- Lamp matrix column test at 2J5 with Leon's code
- Lamp matrix row test at 2J7 with Leon's code
- Diode-test the lamp column and row transistors
- Some lamp columns over-bright: board or playfield?
- Light a lamp row by grounding its transistor
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)