• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Marantz 2285B No Sound. Preamp Issue help needed.

X

xalara76

Active Member
Testing this Marantz 2285B, Quick PS board relay engagement which is good. Tested through Main in on back amp section works beautifully.

Preamp section is dead. barely any sound at all on the right channel and very distorted. Left Channel is dead. IF I press on the preamp board it will come back to life but then trips the relay and cuts out. I retapped all the solder joints but no gives. Any help appreciated..

Thanks
 
Register to hide this ad
Both channels being out, look at the wiring connection pins for bad or cracked solder. Then if nothing is found use a non-conductive tool like a wooden stick and wiggle all of the transistors or any ICs first and then everything else if that doesn't reveal a bad transistor.
 
rBuckner said:
Both channels being out, look at the wiring connection pins for bad or cracked solder. Then if nothing is found use a non-conductive tool like a wooden stick and wiggle all of the transistors or any ICs first and then everything else if that doesn't reveal a bad transistor.
Click to expand...


As stupid as this may sound.. I believe I shorted out the transistors (2SA798) on the toneboard. I was messing around and trying to find if any were bad and slipped with my tool… unit was working perfectly fine and it was my headphones that were bad after all.. by then it was too late and the unit isnt playing any sound now. I looked over all the resistors and they seem fine. I ordered some KSA992’s to join together and replace all the transistors on the toneboard. Hopefully this is it. Powersupply voltages look within spec on P800
 
Noticed that when I press the 15k hz button the relay trips and goes into protect. Any idea what that is about ?
 
xalara76 said:
Noticed that when I press the 15k hz button the relay trips and goes into protect. Any idea what that is about ?
Click to expand...
Get it fixed and then try this again. It may be an artifact of the preamp being bad. I was once taught to go after an obvious problem before trying to "fix" any other issues. They may not be real that is.
 
You must log in or register to reply here.
Back
Top Bottom