Quoted from grantopia:
Are they stuck like that before you press the flipper buttons? When you power the game off do they come down? If so it is something electrical. If not it's likely mechanical. If you can describe what happens in a bit more detail we can get you sorted out.
They're stuck, period. Power off and on, they stay up. I'd ordered new coils and flipper rebuild kit from Marcos and have received them; after watching some videos and reading up a bit more, I'm getting a few new parts (flipper bushings, etc.) to go along with them. I do notice there appears to be a pretty regular sparking issue when the flipper buttons are pressed (at the buttons themselves, and more with the right flipper button than the left), so I'm not sure if that tied into the initial problem as well. I wasn't playing it when both flippers failed, but they did indeed fail at the same time.
Either way, I think the coils likely overheated and the sleeves melted a bit, enough to cause the flippers to stick in the upright position. That, or somebody fed 'em an overdose of Viagra. Anyhow, since the right flipper lane change function was originally intermittent and now isn't working at all, I'm also ordering a few SW-10A-48 (flipper cabinet normally open) switches to go along with the other parts. Hopefully, I'll figure it out - but if anyone else has any suggestions, I'd appreciate it!
Couple of additional questions - the power supply had been upgraded to a Rottendog WDP3211A. I'd purchased one of Inkochnito's Rectifier/Bridge boards to eliminate future problems, but is it still necessary with the Rottendog? Also, anyone know where I can get a new 03-7773-4 drop target for the 'T'? Preferably one with the wedge top!