Wurlitzer 630T Fault

[Guest]

Hi All,</P>


Don't know whether this is the right place to ask, but here goes. I have been asked to repair a Wurlitzer 630T which has a fault in the power supply or main amplifier I suspect.</P>


The 1.6 amp slo-blow wire-ended fuse beneath the power/amp module fails bigtime, indicating a possible failure in the elctrolytics or output transistors. I do not have any circuit diagrams for this model.</P>


Advice, suggestions, comment welcomed</P>


Thanks</P>


roger</P>
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[OrgansR4Me]

Re: Wurlitzer 630T Fault

I don't have that service literature either, Roger, but sounds like you've made a good guess. Failure of the electrolytics is probably the number one cause of audio failure in the older instruments. Found a really interesting article about replacement of the electrolytics when I was researching my 4375. I found it on Google.

[Guest]

Re: Wurlitzer 630T Fault



Hi Organs R4Me,</P>


Thanks for your comments, however this turned out to be trickier than just normal failed electrolytics.</P>


The 1.6 amp slo-blow fuse was being blown by a serious current draw to the point that some fuses actually shattered the glass envelope with the vaporisation of the fuse wire.</P>


Back to the good old testing trick of replacing the fuse with a 60 watt light bulb, as acurrent limiter, which allows debugging to be undertaken without blowing fuses.</P>


The upshot was that 2 faults existed, the 0.047u 250 cap (non-electrolytic) across the mains input short circuited under full applied mains voltage (250Vac). More serious, there was a fault in the main transformer primary winding, which had obviously short-circuited internally.</P>


Replaced the mains transformer with a toroidal type of 25 - 0 - 25 Vac, (nearest replacement voltage available), and the Whirly is back in action.</P>


I was unable to get replacement electrolytics on Christmas Eve, which I normally replaceas a matter of course, so fingers crossed they stand up to the new tranny.</P>


This may help somebody in the future.</P>


Regards</P>


roger</P>
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[OrgansR4Me]

Re: Wurlitzer 630T Fault

Thanks for reporting back. Showsoutstanding troubleshooting skill on your part. You have a great future in organ restoration!

[k1nwb]

Re: Wurlitzer 630T Fault



I realize you post is somewhat old, but I just joined the group and have a lead for service manual if you wish it...</p>

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send email to [email protected] and Janice should be able to help. (she even told my how to open my 4027 and raise the manuals..)
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