2230 is my newest effort

Mike Sweeney

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I finished up my 2285B and I have in place of pride in my loft with the 2226B relegated to the floor right now. I'm still debating on keeping the 2285B but while I noodle that around, I've picked up a 2230 and started the restoration. Overall it's in pretty fair shape other than the power switch is fried, a few bulging caps and every stinking switch stuck or near stuck :eek: I'm debating buying replacements and refurbishing them vs pulling these out and seeing what i can do with it. The speaker select switches are so stiff, you cannot easily push them much less get them to rebound out. I'll probably take those apart first just to see whats up. There is a white powder lightly around the chassis, almost like it was by salt air at one time. And no, I'm not going to taste it :)

I plan to get a new power switch wired in, replace the prime power caps and recap the P/S board.. THEN try a dim bulb test and see what I've got to work with.

I've order some parts from ibuildmarantz not so much I need them, but I want to see the quality of the kits before I recommend them to some of my friends who want to do one off light restorations. I've heard good things so I want to see for myself :)

Here are the glam shots :D You can see how cooked the contacts are for the switch.
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You should be able to free up all the pushbutton switches with some Caig D5 .
I have a power switch and cap if you need it.
You'll do fine after just tackling that 2285B!

Bob
 
No doubt this will be a walk in the park after your others.

I've not had to disassemble any switches yet. I've come close, but eventually got them cleaned out.
 
Here is how to get a new switch into the 2230. It's a tight fit and I found pulling the headphone jack out of the way really helped the access. I will probably slightly elongate the opening because it's hitting the switch shaft and binding now and then. The switch had to be mounted sideways to get the holes to line up since there is a spacing difference between the old and new.
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Why do I leak test my caps? because of this. This is 4700uf at 80volts. OEM cap.. 40 something odd years old. The ESR tester says it's fine.. a bit high on the rating, came in at 5800uf with about 2% loss. Looks good right? wrong!!! I tossed it on my heathkit cap tester ( which I rebuilt and calibrated) and at 50 volts, it leaks like a sieve. Even at 25 volts, it slowly leaks but 50 pushes it right over. And I still l have 30 volts to go for the printed rating. New caps can easily go past their voltage rating and not leak. This cap is junk.. even though it "passed" the ESR testing just fine. Anyone who tries to tell me that 40+ year caps are fine is wasting their breath and risking their gear. I've had over an 80% failure in leakage testing on the main filter caps of the 70's units' I've taken apart so far. The early to late 60s stuff has been 100% failure.

The closed eye tube is the leakage indicator. It's supposed to be "open" which is an inverted V cutout of the green.
 

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Thanks for sharing this. Very important - I wish I could test like that.
 
The eye tube takes me back to the 60’s when my Dad had a Curtis Mathes console unit. It had what they called a “magic eye” for zeroing in on the tuning. Same tube as yours. We kids thought that was about as space age as you could get.:D
 
I love eye tubes- not a lot of friction like a sticky old meter. That said, do you know the leakage current that the eye responds to? Though I've had my fair share of leaky old caps, it's nothing like 80%. All caps leak to some degree, but most of the small ones I pull from '70 stuff are still healthy, as in leak below 50 uA at full rating. Larger filter caps are allowed more, though I really don't like to see them up at the data sheet maximums. I've no use for ESR testers. You need value, losses & DC leakage to know condition. Most of the time I measure just out of curiosity, and replace 'em anyway. BTW, I see values going higher quite often and consider it a sign of impending trouble.
 
The electrolytic rating is leaking more than 20ma when the eye closes which is pretty bad by current standards. The min-electrolytic is 2ma of leakage or more. I’m quoting this from memory right now but I think it's right

My experience shows that current large capacity caps like 8,000uf etc can take up to 3 mins to charge and give an accurate reading for leakage.

For comps, I took a new 63volt 10000uf cap and compared it to this old cap. At 50 volts, it took 2 mins to charge and show no leakage compared to the old cap which never cleared up and show continued leakage at 50 volts

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So this was fun.. good thing I didnt plug it in just yet. Someone had jumped the switch into the ON position.. I can imagine powering it up and then madly hitting the power button to turn it off as all the magic smoke pours out :O

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Final report for today ;) Got a new cap swapped in for the main filter. Got the new switch in place ( waiting for the snubber), cleaned the switches and pots and got the power supply board re-capped. Hit with power and it's ALIVE.. doesnt sound half bad either. Left channel is half the volume of the right but it's not distorted so I'm betting a few bad caps. All except one light is burned out.. both stereo lights are gone but I've got LEDs coming. I need to post a pic of why you swab down the rotary switch after hitting it with DEOxit. The black tarnish will come off with a gentle scrub with a cotton swab. It's interesting how on this model, the covers for the lights are metal and newer are plastic.

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So I pulled the amp board for the left channel and found a very dead cap which explains the low volume but I also pulled the primary transistors and each has a Hfe of 45 and zero thermal compound between the mica and heat sink. There is a film of something that looks like silicon but it's clear and unless you looked for it, you would miss it. Every one of these restorations is an adventure :)
 

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I have removed several undisturbed output transistors from 22xx receivers and found a mostly dried, clear compound under them. Like Tom said, I think they used something clear for many of their units.
 
From what an 'old timer' told me, in the early days, there was no 'thermal grease' with zinc oxide in it, so clear silicone grease was all they had to use.


I guess I'm not as old as I thought ;) That certainly explains what I see. No lock washers either. They were trusting that the screws wouldnt back out over time. These were not "tight" but not finger loose either. Just a bit beyond finger tight.
 
No visible grease on this last 2270. Yes, a really light film of something clear, but very little of it. Must be enough!
 

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1974-2018
That’s 44 years!
Think these old Marantz’s will make it another 40+ years?!

Bob
In a way, this is a sad note... We put our efforts into preserving these beauties and based on what we're seeing - they'll outlive us.
I highly doubt I have another 40 years.
I can say that since I'm sure this gear will be passed on - I'm gonna make sure people know what they are worth. Not just dollars but the history and effort and attention given to these units.

It will help if these threads on AK are still available in 40 years. It would help IN A BIG WAY.

EDIT: that makes me think we should archive all the tech docs onto usb and store inside these units. Think of the relief if a tech opened one up for a repair...
 
EDIT: that makes me think we should archive all the tech docs onto usb and store inside these units. Think of the relief if a tech opened one up for a repair...
Hmmm. Do you think there will be many techs who understand component built audio equipment in 40 years? I kind of doubt it. There will be a handful of vintage nerds around (you know — like us) who will keep the fires burning. But not many. I have two year old twin grand babies who already know all they have to say is “Alexa — Play Twinkle, Twinkle” to have their wish granted. Unfortunately for them, they can’t say “Alexa” plain enough to make something happen. But they already know it just takes a few words to have almost any music you desire played instantly. I can’t even imagine what the world of audio will look like in 40 years.
 
Perhaps.. but my 30 year daughter asked me for a Marantz that I restored. Sounds better than anything else she has or has heard. And she loves the way it looks. She's not a audio nerd.. she's a consumer. But something still speaks after 40 + years.
 
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