Output Suddenly Stopped

[rogercollege]

I picked up a 200A off of Craigslist.  It had a few keys that needed easing but was otherwise in fantastic physical condition.  Sounded good so I bought it.  I brought it home, eased the keys, and everything was hunky-doory.  Then one night I was playing it, walked away for about 30 minutes (leaving the power on), came back to find the output almost completely gone. There is the faintest of signal on both the AUX and headphone jacks but totally unusable. The light comes on normally but no sound.  There was no power outage or thunderstorm etc. 

I'm new to the Wurlitzer ownership so just getting my bearings on things I can do on my own to avoid shipping parts or replacing things unnecessarily. 

That said, I'm looking for advice on a solution to the problem.  I've heard that sometimes dust in or around the reed bar shield, near the pickups, is a common factor in a dropped signal.  I've tried blowing with air to dislodge possible blockage but that hasn't worked.  I've also gone though each key and hit them firmly 5 or 6 times and noticed something interesting.  On the lowest Bflat key, a random pop occurs when firmly struck.  It's a lowpitched crackle sound (possibly at normal volume).. almost as if the correct sound is trying break through but can't.  This happens randomly when I strike that particular key...and not consistently.

Can anyone help me find a solution?

Thanks   

[cinnanon]

Check the fuses. I picked up a 200A off of CL one time that had barely any output through the Aux out. The speakers were not wired up either.  It was a blown fuse on the circuit board.

[pianotuner steveo]

Yes, fuses on the amp board are the most common thing to check first.

Also, a good thing to note here for all Wurlitzer users. Now that it is getting cold, remember that if you gig with one or just are moving one in cold weather, condensation can develop going from warm to cold to warm again, and they may be funky when first turned on again. They need to warm up ( dry out) or they may make crackling noises similar to a shorted reed.
Warming the red far with a air dryer will help if you are in a hurry ( like at a gig)

[rogercollege]

Thanks for the support.  I'm still learning my way around these machines and unfortunately I'm not the most accomplished electrical technician.  I'm better with the non-electrical moving parts but I'm a fast learner. I also find it fascinating and kind of soothing getting my hands dirty with this instrument... 

Anyway, I've eyeballed the fuses and they don't look blown (meaning they don't appear black or burnt around fuse edges).  How would I go about checking accurately?  There are three right?  Two on the electronics board and one around the Power/Tremolo knobs? 

Assuming I'm able to get at accurate assessment, I'm a bit nervous swapping out blown fuses incorrectly and damaging the electronics further.  Can anyone give me a crash course?  I've heard these fuses are tough to replace and read about "fuse jumpers" for use with 200A.  Do you guys recommend this mod? 

Thanks again!

[cinnanon]

Get a digital multimeter and check the resistance of the fuse. If it says "0L" it means zero load, or blown fuse. If it reads 0 ohms, you are good then.

Ken rich sound services sells resettable fuses too.  It doesn't require replacement. Also RadioShack sells inline fuse holders that snap together, so you don't have to solder another fuse in.  All options require some soldering.