Restore a Marantz 2275 for me

[freax]

a few points to name! all switches, balance controls, potentiometer, should be clean with tuner/contact cleaner and always after spraying them start moving and pushing switches/balances "many times" at least 20 times to make sure they are lubricated and cleaned properly, the relays should be clean with very fine metal sand paper that way the contacts are real clean and shiny and make good contacts. Those Marantz are very good units for sure, but look for dry-out caps and change them also bad connections. make sure you have the schematic and adjust bias and dc-offset.

Yeah, I would but the only "contact cleaner" that I have available is WD40. I bought deoxit but now after reading about it I'm not so sure if I should use it. Does anyone have names for some better alternatives?

So far so good anyway, the amp is still playing 2 hours later. AM radio is quite nice and low noise, has a small hum but that is to be expected, FM is nice and loud/transparent aswell, especially when using an FM Transmitter plugged into my iPad inorder to stream shoutcast's "Radio Vintage" to the Marantz 2275, quite nice.

The amp modules aren't overly hot, just warm, so they seem to be going good too.

I have to wait before I can buy capacitors for this 2275, because I blew all of my cash on the Russian TDA1543 DAC

 

[freax]

Going to go and pickup my Oscilloscope, which could very well need repairing aswell, seeing as its 40 years old.

Might be a good idea to throw some test signals at this marantz and monitor them on the oscope....I sure can't hear any distortion though, aside from the FM TX's.

 

[freax]

The transistors on the power amp boards are notorious for becoming leaky after this many years. Usually it starts out with the sound in one channel becoming distorted, maybe intermittantly, then all the time. You need to replace the electrolytics on the amp board if you have not already done so, the protection relay, etc., and then the transistors (the pairs) in that channels board. The outputs usually are not the problem. I have three 2275's and one of them did this a couple of years ago.

If it is just the relay, be aware of the transistor issue....

You can isolate it to the specific amp board just by switching them, since they plug-in. If the trouble follows, you know where it is....

Yep, started doing it just then, but it didn't do it all morning from 7:30am up until about 10:30am and it was operating perfectly, I guess the electrolyte is forming overnight then evaporating the longer I run the amp?, left channel started becoming distorted then winked out gradually, all within about 5-10 seconds. also curiously at both times it stared to play up only after plugging either a cd player into the aux port, or a turntable into the phono port, each time i've applied pressure to the front underneath the tone board inorder to keep the amp from falling off this very short depth table.

I'm thinking that we could have an issue with the tone board later down the track...

I'll keep it powered down then I guess until I can replace the caps.

Been playing it nearly all day Its got an addictive sound to it especially with vinyl sources!

Anyway gnight folks.

 

[Coconuts 500]

Your problems most likely aren't with caps, but with dirty controls. Dirty controls can do whatever they want. Anything can happen. You can troubleshoot for days, and never find the issue. Then it turns out it was just some button that needed cleaning. They must be cleaned.

 

[TANDBERGEREN]

Yeah, I would but the only "contact cleaner" that I have available is WD40. I bought deoxit but now after reading about it I'm not so sure if I should use it. Does anyone have names for some better alternatives?

So far so good anyway, the amp is still playing 2 hours later. AM radio is quite nice and low noise, has a small hum but that is to be expected, FM is nice and loud/transparent aswell, especially when using an FM Transmitter plugged into my iPad inorder to stream shoutcast's "Radio Vintage" to the Marantz 2275, quite nice.

The amp modules aren't overly hot, just warm, so they seem to be going good too.

I have to wait before I can buy capacitors for this 2275, because I blew all of my cash on the Russian TDA1543 DAC

I really hope you keep thet WD40 far, far away from Your amp?
It is in no way suitable for cleaning potmeters anyway.
It might be OK for some switches,m but since many of the switches used in -70 amps were made of, among other materials, Nylon You never ever shoult put anything containing petroleum or destillates of petroleum in them.
You only destroy the nylon, and thereby the switches.
Potensiometers also deteriaqtes quite fast when sprayed wit WD40, 565 or similar.

Please use special adapted contact cleaner/lubricant to perform such tasks.

 

[freax]

I really hope you keep thet WD40 far, far away from Your amp?
It is in no way suitable for cleaning potmeters anyway.
Please use special adapted contact cleaner/lubricant to perform such tasks.

Yes it is not going anywhere near any of my amps or equipment, I bought it for use on cleaning car parts, thats it.

I'm just waiting for my deoxit to arrive, still..

 

[sssmokin99]

yeah, dont use WD40 on that thing, lol.

I used to sell a parts kit for these (caps, relay, etc). PM me if you want more info....