Marantz 500 Restoration, Here we go...

[Salbreth1]

Hey guys,

Its been a while but I'm starting a build on this guy and thought you might be interested. This unit was running when before I received it, but things are never that easy. When I powered it up there was an immediate smoke storm and it popped the 15 amp fuse. Challenge accepted.

 

[bryans12v]

 

[blhagstrom]

Been there, done that, wishing you luck.

 

[Steven Tate]

I'm glad it's you and not me, but this will be fun to watch.

 

[Bert 1100]

 

[Richs_Trains]

love these!

 

[rBuckner]

Bunch of rubberneckers! Say, move over and let me see.....

 

[Steven Tate]

Y

Bunch of rubberneckers! Say, move over and let me see.....

You have to buy some popcorn first.

 

[Jailtime]

I'll pull up a chair for this one.

 

[tonebells]

I am in!

 

[airtime]

Hey,can I add my worthless two cents in here too! I think that amp needs fixing - eh?

I'm not familiar with the 500 but it looks interesting.

Buckle up boys because it's going to be a bumpy ride.

 

[Salbreth1]

There's a lot of popcorn in this room. Ill order more...

So I discovered the problem. I assume the bottom cover was off before I got it because a wire was caught between the cover and chassis coming from the inrush relay to the 30w resistor. Took out the fuse but that's it. The resistor blew out the side but oddly enough, its still good. Something tell me the resistor was like this already.

So I reattached things and brought it up slow. Lucky me, all is well. I went through the PITA adjustment procedure and everything regulated nicley! One driver board has a few different transistors on it and 2 caps replaced but everything else is original. Some of the traces on the replaced parts are a little rough. But this thing is gonna get the royal treatment and sing beautiful melodies once again.


Something tells me this resistor has seen better days.

 

[Steven Tate]

So, entering the first turn, the audio gods are smiling on you. Let's hope they stay happy.

 

[bryans12v]

If you need some image references, here are some good ones on a 500 restore.

http://amp8.com/tr-amp/marantz/mar_500.htm

 

[KutzlerTrans]

i am sure, Sal, that you will do a fantastic job on this bad machine

Think it will put your 300dc to shame??

 

[bluefan]

Ahhhhhh... I think it just needs recapped... ....and DeOxit
Give me my PoPcorn

 

[jstang]

It ain't easy..... I have one on the bench right now too.

Jk

 

[Salbreth1]

The amp boards look good, everything is original. I plan to replace all the outputs as per the service bulliten. Looks like two were replaced on one channel as well as a driver.

 

[Salbreth1]

So just got back to this and finished the relay board, mostly. All TO-92s, diodes and capacitors were replaced. The relay contacts are in great shape so I put a mirror back on them and soldered them back in. Somehow I deleted the 8200uf caps from my cart so I'm waiting for them... Amplifiers are next!

 

[Salbreth1]

One channel stripped and cleaned. Pots flushed and lubed. The few resistors I'm leaving are dead on, but all the carbons are out as well as the emitter resistors.