DE Tommy boot problems

[mrwierdwrench]

My Tommy has recently become unplayable. When I first turn it on the +5v and PIA leds light, after 30 to45 sec. Pia led goes out, blank led comes on. All playfield lights work, nothing else works. When running diagnostics, flippers won't clear the trough, speakers work, mirror test does not work, blinders do work, all lights work, cycling coils- none fire, coil test - flippers cycle through- none fire. I'm well versed in Em repairs, but this has me stumped, any help would really(!!) be appreciated. Thanks

[John Robertson]

Post by mrwierdwrench
My Tommy has recently become unplayable. When I first turn it on the +5v and PIA leds light, after 30 to45 sec. Pia led goes out, blank led comes on. All playfield lights work, nothing else works. When running diagnostics, flippers won't clear the trough, speakers work, mirror test does not work, blinders do work, all lights work, cycling coils- none fire, coil test - flippers cycle through- none fire. I'm well versed in Em repairs, but this has me stumped, any help would really(!!) be appreciated. Thanks

Usinga good voltmeter check that the DC voltages are as shown on the
schematics. Use your AC voltage setting on the meter as well to see if
there is excessive AC ripple on the DC lines. The 5VDC should have
around 0.1VAC or less of AC voltage present.

Note that not all electronic voltmeters measure AC on DC lines the same
way. Test with a battery, it should show 0VAC but the correct (ish) DC
voltage. A car battery would be a good test source for both AC and DC -
this with with the engine off. If the meter shows anything on the AC
range (20VAC perhaps) on the battery then that instrument is somewhat
useless for servicing solid state gear and you should spend a bit more
on a better grade of meter.

John :-#)#

[mrwierdwrench]

I have a good voltmeter, and am experienced in using it, just not sure where to start! Any suggestions? Thank you!!