Marantz 2325 gift, but problems...

[moondog]

Hey Folks... Long time member. Joined in 2002, but haven't been around much since I pretty much found my "Nirvana System" after years of buying, trading & selling quite a few years ago. To all of you old timers still here, I hope you've been well & nice to be back. I'll try & make this story as short as possible...

A few weeks ago my ex-brother in law dropped by & gave me some of his old stereo equipment that had been sitting for over 25 years. A Marantz 2325 (with wood case), Teac A-7010 & Beogram 2400. I was blown away! Especially with the Marantz. Anyway, the 2325 was in really nice condition, so I of course wanted to get it back up & singing again asap. When I first plugged it in I used an old crap BSR speaker to test it. Did the the right side first (clear sound) Left side next (intermittent sound), so I grabbed a can of Deoxit & started cleaning all the controls. After I was done, I fired it back up and checked each speaker again. Both came through clearly, although the second speaker channel I had trouble with took longer to kick in after restarting. At that point I was just excited, so I hooked up a pair of my ADS's to it, pulled a favorite CD & prepared to chill with some Jefferson Airplane. WRONG! No sound at all from either speaker. Tried the Aux, Tape, Phono, FM`... NADA. I was totally bummed as well as confused. What happened between those 5 minutes??? Pulled out my multimeter & checked the power board voltage. Spot on... 35V. WTF? The obvious problem is the speaker relay is not kicking in at all. I cleaned it good, but still nothing. I was gonna order a new one right away, but thought I'd ask around for other's experience's first.

Any ideas would be very much appreciated.
Thanks, mOOndog

BTW... I was totally heart broken to hear of the unfortunate passing of AK's ultimate "Ball Buster" Toasted Almond. He was one of a kind & I miss him. God Speed Brother. I will play some Zappa in your honor my friend.

 

[moondog]

Here it is before I cleaned it...

 

[c.coyle]

. . . The obvious problem is the speaker relay is not kicking in at all. I cleaned it good, but still nothing. I was gonna order a new one right away, but thought I'd ask around for other's experience's first.

I am not familiar with that unit, but I suggest checking the DC offset first. That's primarily what a speaker relay is designed to do: protect the speakers if too much DC escapes the amp.

You will need your multimeter and a careful reading of this well-known post.

If you haven't already, download the service manual from Hi-Fi Engine.

 

[mech986]

Good to see you back moondog. Unfortunately we’ve lost a number of members over the past few years. There’s a memorial thread here that summarizes those that we know are gone, search for it.

As for the 2325, yes, check offset pre-relay but be extra careful with any meter probes, use mini-clip on types if possible on test points and study the service manual and 2325 troubleshooting threads. Many times the actual bias and offset adjustment pots need to be set and or cleaned. And of course, recaps May also be needed if the unit has sat for a long time or if adjustments are unstable. Be cautious and methodical.

Such a nice gesture by you ex-BIL.

 

[Chrisxo55441]

from the pic it looks like the tape monitor and tone buttons are depressed. put the monitor out if you havent already

 

[SaturationPt]

First of all let me tell you that those are nothing but trouble, I will bail you out by picking it up this evening for my own collection. In fact, I'll double your money!

I strongly agree with the above to check offset and idle, it's pretty easy on the 2325 (most things are, very servicable design). Be careful not to slip and short something, ... lots of current available to let the smoke out. To further that caveat I bought a receiver yesterday from its previous owner who had two speakers catch fire when the long-stored receiver he decided to play for its first time railed a channel.

Now on to troubleshooting:

I have found that by a large margin, the most common cause of intermittant and channel drop-out is switches, pots, and protection relays. A pretty sure sign an intermittant is a speaker relay is when you turn the volume high enough, the channel cuts in (and usually stays), pretty sure sign of a pot or switch is a crackling/popping when operating the switch or pot.

Another possibility with the 2325 (and most Marantzes of this era) is that the internal-shorting switch in the AMPLIFIER IN jack is dirty. Try plugging a pair of RCA cables from the Pre-out to the Amp-in to eliminate that possibility (a little spritz of de-oxit on the plug/jack first helps to clean and lubricate old dirty jacks).

Should that fail to produce, try a low-level input into the amp-in jacks, if nothing on one or both channels it's in the amplifier or protection relay, if both channels play perfectly then in the preamp stages. Be careful as this is a full-volume (non-mastered) input, start at low volume and the receiver off.

Also look at switch positions as mentioned above. IIRC the 2325 bypasses the tone board and controls when you have tone switched out, another way to narrow down where the problem lies.

Good luck on a very well-built and desirable receiver, ... and if you choose to take me up on the offer of a free receiver (or double free), ...

<edit> Speaker relays are an always replace item for me, if it isn't the problem, it's certainly a problem. If I remember correctly, my 2325 had a bad relay or bad solder to the relay, think it was the former. Cleaning? Good luck but that doesn't usually do much, you've already burned through (and now filed/sanded through) the top layer of the contacts (the actual contact metal by design) and they'll go bad again very soon.

Always amazes me that people will buy gold-plated speaker pins and worry about expensive speaker cables but are fine running it all through a half-century-old pellet of moving and worn low-conductivity metal with a contact point smaller than the head of a pin.

 

[moondog]

Thanks folks for your input. Sorry for the late reply. I've been out of town. Still no sound. I have a buddy coming over with test equipment tomorrow to try & pinpoint what might be happening. This things starting to be a major headache. Ordered new lamps for it only to find out when I went to replace them that the circuit board with the sockets attached was cracked, so only 3 lamps work. Still haven't figured out how to maybe repair that either.

Oh well... Thanks again for your help. I'll keep you posted.

 

[SaturationPt]

It's a single-sided circuit board. I would lay it circuit-side down, epoxy it together and add a couple of layers of epoxy over the cracked area, then when fairly solid flip it, scrape the solder-resist back from the broken traces, lay a piece of ~ 18AWG wire across the broken areas in each trace and solder them down, should make it strong enough for what it's doing.

I have to say though, if that's all it's going to throw at you, ... it's an easy one!