Marantz 240 main fuse blowing

[akabek]

I recently had both channels of my Marantz 240 rebuilt. I hooked up my Marantz 3300 preamp and the main fuse blew in the 240 within a few minutes. Previously i had used the 3300 with a Sony 2000 amp without issue. I replaced the fuse in the 240 and connected my Sony TA3200F preamp . The pair worked well for a couple of weeks and last night the main fuse blew again I the 240.

Would a preamp cause this? Is the issue with the 240 amp? Let me know your thoughts.

 

[jd3rdcoast]

Logic would say it's the 240. I would get back with your tech that did the rebuild to check the unit for you. Hopefully he will warranty the work he did on the amp.

 

[ivandezande]

Sounds like you have a bad tech.

 

[akabek]

Ok thanks

 

[dankik]

Here is the schematic for the AC power transformer. The main fuse is in series with the two primary windings. I don't think any part of the amplifier circuit could blow this fuse unless there is a short in the transformer or in the wiring from the plug/outlet to Terminal Block (TB1). Check the wiring of the terminal block for loose wires or bad solder connections. (See wiring schematic below)