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Electronics => Repair => Topic started by: Bargainhunter on April 28, 2021, 08:08:17 pm

Title: Fisher power amp keeps blowing line fuse.
Post by: Bargainhunter on April 28, 2021, 08:08:17 pm

I can't seem to find the reason my Fisher amplifier keeps blowing the 7 amp slo-blo fuse.  It plays fine on my test bench but when I connect it up the my other equipment. The fuse will blow.  Sometimes it plays for days without blowing the fuse.  I checked my speakers and speaker connections and no problem.  I checked the fisher to see if one side of the line was connected to the chassis but it's okay. Yesterday  the fuse blew again and I replaced it. The fuse again blew so I reversed the AC plug (not polarized) and the fuse did not blow. My next step is to see if my pre-amp has one side of the AC line connected to ground.  This may or may not be associated with the fuse blowing but after playing a tape on my Pioneer RT-909, the tape will slow down after 15 minutes or so.  Any ideas?  I've attached the schematic of the Fisher amp.

Thank you for your help.