• 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 2235B cuts out at roughly 1/2 volume

Then take out the main amp board and the first thing to do is to replace the differential transistor pair and check.
 
cyber104 said:
Hi All:

Not even sure to start looking on this one and I'm certainly not an electronics expert - just a lover of vintage electronics and a basement hack.

I recently picked up a 2235B that works fine and sounds perfect until it gets to roughly 1/2 volume. At that point it kicks the speaker relay and the there is no volume at the speakers. Once you turn the volume knob down a bit, the speaker relay clicks and the sound comes back.

Trying to isolate the problem between the pre-amp and power amp section I plugged the pre-out out of my 2235 directly into the main-in of the 2235B - same thing happens at roughly the same volume setting on the 2235 - so that sounds like the power amp on the 2235B is doing this.

Any thoughts?

Thanks much
Chris
Click to expand...
Chris, take a look at the P800 board. It's the board that the relay is mounted on. A member recently had an issue with his 2250, which has the identical protection board. He cleared a similar trouble by reflowing the solder joints on the board. The input to the board from each channel can be monitored at J809 and J810.

Marantz 2250 - Is this what I get by changing the value of capacitors? | Audiokarma Home Audio Stereo Discussion Forums
 
Last edited:
Thank you for your response Ray. Since I'm a novice and didn't want to mess up a piece of nice gear I sent it up the the repair shop I use in Asheville, NC. He called yesterday and said he believes it's just 2 bad caps. He didn't mention which 2 he believes are bad but he's trustworthy and has fixed lots of gear for me. After he fixes it I'll make sure to update this post with the solution in hopes that it may help someone in the future.

Thanks again everyone for your suggestions
Chris
 
Here's my final follow up - the receiver is fixed. It's wasn't just 2 bad filter caps - in fact - even though those caps were out of spec they still worked OK. The problem was with the power supply caps.
 
You must log in or register to reply here.
Back
Top Bottom