It was suggested I test DC voltages to both C514 & 515 as well as pull the 6X4 and test the AC coming in. 80VDC on C514. 69VDC on C515. C514 was heating up with these tests so I switched off the machine as soon as I could read the voltage. With the 6X4 pulled I next tested 313VAC coming from the transformer to pin 7 of the 6X4 socket but then something unexpected happened: C514 blew. There should have been no voltage reaching either cap with the tube pulled. This suggests a short somewhere but I can't visually see any short. How else would voltage reach the caps? I'm replacing both caps & getting a new 6X4 next week but I don't see this solving the problem if the cap blows with the tube out. Any ideas or suggestions welcomed.
jerold k
A pinched wire somewhere? A solder glob which went astray and is shorting something out?
Maybe you could post a high resolution image from the underside of the chassis for others to view and possibly help you pinpoint the problem?
"A picture is worth a thousand words"
Donald R. Resor Jr. T. W. & T. C. Svc. Co. http://hammondorganservice.com Hammond USA warranty service "Most people don’t have a sense of humor. They think they do, but they don’t." --Jonathan Winters
-----Original Message----- From: jukebox-list-bounces@lists.netlojix.com jukebox-list-bounces@lists.netlojix.com On Behalf Of Jerold Kress via Jukebox-list Sent: Sunday, January 15, 2023 3:34 PM To: jukebox-list@lists.netlojix.com Subject: [Jukebox-list] FOLLOW UP TO SEEBURG TSU5 ISSUE
It was suggested I test DC voltages to both C514 & 515 as well as pull the 6X4 and test the AC coming in. 80VDC on C514. 69VDC on C515. C514 was heating up with these tests so I switched off the machine as soon as I could read the voltage. With the 6X4 pulled I next tested 313VAC coming from the transformer to pin 7 of the 6X4 socket but then something unexpected happened: C514 blew. There should have been no voltage reaching either cap with the tube pulled. This suggests a short somewhere but I can't visually see any short. How else would voltage reach the caps? I'm replacing both caps & getting a new 6X4 next week but I don't see this solving the problem if the cap blows with the tube out. Any ideas or suggestions welcomed.
jerold k
_______________________________________________ Jukebox-list mailing list Jukebox-list@lists.netlojix.com http://lists.netlojix.com/mailman/listinfo/jukebox-list Searchable Archives: http://jukebox.markmail.org/
With that cap blown and presumably removed from the circuit, have you tested for AC on the point where it was connected? I'de examine the wiring around that area and look for mistakes in rebuilding.
Regarding the 6X4,I’ve eliminated those tubes since 1988.
I use two diodes in series rated at 800V or more (for extra safety) into an approx 220 ohm, 5 watt resistor and through a 0.5 amp fuse. The diodes and resistor are mounted on a terminal strip I place on the inner wall of the chassis near the first filter.
The fuse is inside an in-line holder due to the higher voltage involved.
RobNYC
On Sunday, January 15, 2023, 06:34:06 PM GMT-5, Jerold Kress via Jukebox-list jukebox-list@lists.netlojix.com wrote:
It was suggested I test DC voltages to both C514 & 515 as well as pull the 6X4 and test the AC coming in. 80VDC on C514. 69VDC on C515. C514 was heating up with these tests so I switched off the machine as soon as I could read the voltage. With the 6X4 pulled I next tested 313VAC coming from the transformer to pin 7 of the 6X4 socket but then something unexpected happened: C514 blew. There should have been no voltage reaching either cap with the tube pulled. This suggests a short somewhere but I can't visually see any short. How else would voltage reach the caps? I'm replacing both caps & getting a new 6X4 next week but I don't see this solving the problem if the cap blows with the tube out. Any ideas or suggestions welcomed.
jerold k
_______________________________________________ Jukebox-list mailing list Jukebox-list@lists.netlojix.com http://lists.netlojix.com/mailman/listinfo/jukebox-list Searchable Archives: http://jukebox.markmail.org/
jukebox-list@lists.netlojix.com
-
Chan Gade -
D. Resor -
Jerold Kress