Hello all,
I recently received a Dual 721 with badly damaged dust cover and base. Everything else looks clean and dandy but the 1.25amp fuse in the power supply was blown when I received it. I can build a hardwood base and dust cover, but I am somewhat challenged when it comes to electronics. I can solder and have a digital voltmeter And can follow instructions concerning circuit diagrams.
How should I safely approach troubleshooting the cause of the blown fuse? I have 230v at the power supply.
thanks in advance,
Peter
I recently received a Dual 721 with badly damaged dust cover and base. Everything else looks clean and dandy but the 1.25amp fuse in the power supply was blown when I received it. I can build a hardwood base and dust cover, but I am somewhat challenged when it comes to electronics. I can solder and have a digital voltmeter And can follow instructions concerning circuit diagrams.
How should I safely approach troubleshooting the cause of the blown fuse? I have 230v at the power supply.
thanks in advance,
Peter
Hi Peter, why do you have 230V at the power supply? You can switch the DUAL to 110V. However, start with disconnecting the secondary part of the Transformer and check if you have 20V on the output of the transformer. As you can see on the schematic it is not a 1.25 amp fuse, it's 0.125 amp.
Thank you for the guidance. I’ve just moved to Spain, so that is the reason for 220v supply.
I jumped across the fuseholder(not sure I can find .125A fuse in my area), disconnected the output of transformer and measured 20v output.
I assume that the motor cover needs to be removed to measure voltages downstream. Can I safely proceed testing without the fuse, or should I buy a few? The motor spins freely by hand.
much appreciated.
Peter
I jumped across the fuseholder(not sure I can find .125A fuse in my area), disconnected the output of transformer and measured 20v output.
I assume that the motor cover needs to be removed to measure voltages downstream. Can I safely proceed testing without the fuse, or should I buy a few? The motor spins freely by hand.
much appreciated.
Peter
belated thanks for the guidance. I ordered some 0.125amp fuses from China, since I could’t find any locally.
they arrived yesterday. Installed one and the 721 works beautifully, except for auto start. I prefer to cue manually anyway, so no big deal. Thanks again,
Peter
they arrived yesterday. Installed one and the 721 works beautifully, except for auto start. I prefer to cue manually anyway, so no big deal. Thanks again,
Peter
Congrats, and glad to hear the transformer and PSU appear to be ok. For the defunct automatic start and return, please check the so called »Steuerpimpel«, part #235 in this exploded view.
What a pity your acrylic hood is severely damaged 😵 .
Best regards!
What a pity your acrylic hood is severely damaged 😵 .
Best regards!
Kay, the steurepimpel is fine. The start lever(I think), item 178 was sticking. And preventing the motor from staying on in auto mode. I cleaned it and put a very light drop of oil on the mating surfaces, activated it a few times. Now works fine in auto and manual. The seller told me that the turntable hadn’t been used much and gummy lubes seem to indicate that.