I finally have some time to go over my F-14. The upper diverter locked on and smoked the coil. I have replaced the coil and both transistors and it seems to be back. But I noticed a couple of large resistors in the bottom and tracked them to resister boards scattered around the bottom of the playfield. Apparently these are used to provide warming voltage for the flasher bulbs. So I ordered a bunch of replacement resistors of both 330 ohm and 5 ohm varieties. I replaced them and went into the flasher test. It worked fine for about a minute. The flasher in the ramp diverter by the right flipper stopped working. When I checked, the 5 ohm resister had popped the wire on one end and the other end had popped the trace right off the board.

Based on a little research it looks like the best option might be to replace the #89 bulbs with LEDs and remove the resistors altogether.

Before I do that, I would like to know why this brand new resistor broke like that and if that presents a danger to the LEDs once they are installed. So if you have replaced the incandescent bulbs with LEDs, which of the two major processes did you use. (a) remove the 330 ohm resistors or (b) remove the ground(s) to the resistor boards.

Thanks in advance for any input. I have a few days as I still need to source and purchase the LED replacements. I would just like to do this once the right way the first time for a change.

ken

Thanks for the replies.

I replaced the resistors with exact replacements both wattage and ohmage (5 ohm 10W and 330 ohm 7W wire wound ceramic bodies) from Great Plains Electronics. The only difference was the new ones were bright shiny white.

The resistors were mounted about 1/4 off the PCB for ventilation, matching the originals as well.

I should have the LEDs in a few days. I will just need to schedule some time to finish them up.

ken

It was just the one. I'll try to remember to take pictures before I mod the boards for LEDs.

ken

It was the 5ohm 10W resister that broke. See attached pictures. Second picture shows where the trace was blown off (in red circle). The first pic shows the end of the 5 ohm resister where the wire broke right at the surface of the resistor.

ken

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