Gottlieb system 3 Flash lamp always on

[Martin.D]

Posted similar problem on my World Poker Tour (Still tracing that fault), so thanks to lukewells I have better understanding of where to look.

Cue Ball Wizard Red Flash Lamp (18) on Relay & Solenoid test remains on all the time, but also behaves odd when tested lights a little brighter and when machine turned off does not go out quickly (Specially if I install LED flash lamp).
So I check Q19 listed on schematics and test transistor, resistors & capacitors in this area. The all operating that same as one another apart from capacitor C30 who reads 1400 not 1900 in direction and 1000 not 1900 when swap the probes.

Is this the source of problem or should I be looking else where?

 

[drhex]

How do you test the cap?
Usually the driver shorted out. The coil power caps are discharging through the lamp when switched off which is why it stays lit.

 

[Martin.D]

How do you test the cap?
Usually the driver shorted out. The coil power caps are discharging through the lamp when switched off which is why it stays lit.

You are right. Was not testing transistor mosfet correctly. Thanks to YouTube video for that one. Sadly not much experience fixing or finding these types of faults. Still learning
Transistor mosfet Q19 appears to be faulty, test passing current between drain & source. BUT another test I learned can lead incorrect testing as possible activate without knowing.
Hoping capacitor C30 is not damaged. Planning to replace transistor mosfet and see if this fixes fault. Will put post results here.

BTW any idea where to get Capacitor 0.1uf 10_ 50v as listed in Gottlieb schematics? Can not seem to find anyone selling them.

 

[drhex]

All the big parts suppliers should carry them, eg https://uk.rs-online.com/web/c/?searchTerm=0.1+uf+100v

 

[Paul]

BTW any idea where to get Capacitor 0.1uf 10_ 50v as listed in Gottlieb schematics? Can not seem to find anyone selling them.

I'm pretty good at locating components. Got a pic of it anywhere?
Is there anything else listed in the parts list/cct diagram that gives any more info about the type (Tant, Elect etc)
0.1uf @ 50v sounds like a decoupling cap...

 

[Martin.D]

Just rechecked schematics lists Capacitor 0.1uf +80% -20% 50v, part number XO-229 Reference U1.
Few places in US but not in UK.

 

[Paul]

Drop me a PM Martin - i have hundreds of those - will throw a few in the post for you...