Jammed lock

Naturally, after many successful attempts at unlocking and removing the back door of the 2504 to adjust the tone and balance controls on the amp, I put the key in and the key won't turn. I tried putting lube on the key but that didn't help. Any suggestions? I really don't want to drill out the lock or force it. Help!

Didja try my favorite tool --Dy-no-mite ?? Works EVERY time ! All kidding aside, if it is the correct key, and an original WurliTzer "W" lock, and key, wipe all of whatever you put on the key off, and use powered graphite in the lock. Insert the key into the lock several times after the graphite has been inserted--without attempting to turn it. Then add another small amount of graphite to the lock and try to turn it--You MAY need to use a new key, especially if the old one is worn. HTH Ron Rich

Hey Ron - I can only assume that the lock is original and the key doesn't appear to be worn. I'll try the graphite. Thanks.

Don't need to assume--If original, the key will be the same as for the side lock--and marked "RW 90". The lock, in most, but not all cases, on a WurliTzer, is also marked the same way. Ron Rich