Yikes! The right playfield GI circuit is out, and it's because fuse F106 is blown.
Here's what the built-in documentation tells me. I'll need this to track the problem down later.
Wht-vio vio
Pf J120-11 120-6
Bb J121-11 121-6
F106 5 amp sb
Driver q12
Hypothesis: stock bulbs consume too much power. As designed, the strand is right at the limit of what the fuse will allow. Old dirty bulbs may be using excess power. Let's do some algebra:
Watts = volts * amps
Watts per bulb = 8 (I think)
Volts = 6.8
Amps(max) = 5
X = max number of bulbs
So unless I'm confused, 8x = 6.8 * 5, and x = 4.25, suggesting that a maximum of 4 8-watt bulbs can be run in parallel on a 6.8V GI circuit with a 5 amp fuse. This seems quite low. How many bulbs are on this circuit (I'm out of town, or I'd be actually doing this instead of writing a dissertation on it)? I probably *am* confused, because the manual says up to 18 bulbs might be strung on a given GI circuit.
The plan:
- Trace this GI circuit under the playfield (wht-vio vio) and replace each bulb with the reduced-power version. Record each location.
- Reseat and inspect power driver board connectors for heat damage: J119, J120, J121.
- Replace F106. Cross fingers, test. Verify each bulb is lit.
- Preventative measures: replace the bulbs on the other 4 GI strands, record bulb locations, verify lighting on each bulb.
Posted by: spblat at January 13, 2005 02:19 PM