Tech Square

Posted by TubeAcolyte (A) on September 13, 2010 at 13:41:22

Hi!

I've got a finicky Marantz MR-1150, and I haven't the money to buy a new one, so I'm looking if I could get some advice as to where the problem may be here, and from there see if it may be a resistor or cap issue, and go to the right people to get her fixed up. The Marantz is hooked up to two Kenwood JL-545 8ohm 140W floor speakers. I have my computer (from an Audigy2 ZS) connected into the AUX channel. The problem is the unit, I'm positive. I've ruled everything else out.

Once in a while, it could be off the bat when I turn the unit on, as much as it could be after 10 minutes, or after an hour. The right channel eventually starts acting up and cuts in and out. The FM produces this problem, but much less fequently than the AUX channel. I don't use AM very much as I'm in a basement, and I haven't tried the Phono input.

The problem occurs most often at low volumes with the AUX input. The sound suddenly becomes scrathy and poppy for between 1-10s, upon which it either returns to normal, or it cuts out completely and sometimes a small signal can be heard from the speaker. When it cuts out, the needle the right channel drops to zero.

Using FM, the problem hardly ever occurs. The AUX channel is ridiculous. I have to keep the volume cranked in order to avoid the problem completely. MOST of the time when it's acting up, if I give the unit a kick of loud, it comes right back. I keep the volume at -45db (ref: -80db), and I adjust my computer's volume from there. At 50%, it's as loud or a little louder than a normal conversation, and at 100%, I'm blasting through the house.

Some other symptoms are:
- The Phono input has cross over from the AUX input INTO THE RIGHT CHANNEL if the comp's master is at its loudest.
- Sometimes, the left channel behaves in the a similar way, but, the left channel needle DOESN'T drop like the right.

I know, I have a cr*p unit, and I should replace it, but when it works it sounds nice, and anything else I've hooked up sounds like garbage. What are these symptoms indicative of on a technical level? Bad caps? Resistors?

Thanks for any help you have to offer :)

Don