hifi engine

Marantz 2275

John Burke's picture

I have a Marantz 2275. At low volume the channels distort, the sound weakens and sometimes one or the other channel will cut out completely. If I turn the volume all the way up it will restore lost sound to the channel that has cut out (both channels do it) sometimes the volume on one channel will get weak while the other channel cuts out completely. There is also crackling and popping sounds sometimes. If I leave the volume a little higher than low the unit works fine. No channel cutting out or weakening sound.

Anybody have an idea what it is. I thought about replacing the main caps (55v 1300 uf!



Re: Marantz 2275

John,

Did you give the switches and pots a good cleaning with Deoxit?

I don't mean to over-simplify the problem but it's surprising how often symptoms you describe are the results of dirty contacts.

Best Regards,
Mike

John Burke's picture

Re: Marantz 2275

I hate to show my ignorance, but what is a protection relay? I have a schematic for the unit, but I wouldn't know where to look!!

Re: Marantz 2275

Your protection relay will disconnect the speaker outputs if there is a problem with the amplifier. It's a switch, but electrically operated; it has a plastic case about 3/4" x 1". The audio from the amp goes through the switch contacts; if they are dirty you can get your symptoms. Your protection relay is on the P800 board, which is also the power supply filter board (I think it's under the chassis on the bottom). This relay is soldered in; if you are not familiar with electronics maybe you should have a tech look at it. I normally just clean the contacts, with a spray cleaner or by hand with a small tool that looks something like a file.

Re: Marantz 2275

Clean or replace your protection relay.

John Burke's picture

Re: Marantz 2275

I think that cleaning the protection relay may have worked. So far the problem has cleared up. I am keeping my fingers crossed.

I have another question two of the indicator lights (dolby and AM) are out and one of the dial lights needs replacing. Is this a big job? Where can I get the lamps? The function indicator lights are 8v, 0.04A and the dial lamps are 8v, 0.2A (200 milliamps). It looks like the dial lamps are fuse type lamps?

Again thanks to you both for your help!

Re: Marantz 2275

The 8 volt fuse-type lamps are available on eBay; not sure where to get the other lamp. I recommend replacing all the fuse-type lamps at once; the working ones will fail soon.
Could be a big job if you've never done it before; the metal bracket that has the lamps inside has to be pulled back after the screw are removed; it's right next to the tuner assembly and it's a pain to remove the old lamps and get the new ones in. I use hemostats to hold the lamps. Make sure you don't mess up the tuner dial cord.

John Burke's picture

Re: Marantz 2275

There is a web site that sells a complete re-lamp kit including the fuse type dial lamps, the indicator lamps and meter and tuning guide lamps. The sites sells two kits. One is a ":bi-pin" function indicator lamp and the other has indicator lamps which are not "bi-pin." How do I find out if the function indicator lamps are "bi-pin" or not?

Also is it necessary to remove the face plate to get to the lamps or can I go from the top?

Re: Marantz 2275

The bi-pin lamps are the ones that have a white base made of plastic. They solder in.