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4230 dial pointer adjustment.

Richs_Trains

Richs_Trains

Well-Known Member
Hello all,

I just completed my first attempt at a partial recap of a working unit (I tried one on a blown up unit and at least got it working, but not perfect). I changed out all the electrolytic caps on the power supply board and both the power amp boards. Everything was a success and it sounds great, I put in LEDs and it looks great also, my problem, and this existed prior to my recap, the dial pointer is off just a bit. The unit gets my station at 88.1, but the pointer is physically lower than 88 on the dial scale. I tried to search a thread to fix this, and I can live with it, but if there is an easy fix, I would love to get it right. P.S. I am not a tech and although I read all this cool rebuilds on this site, a lot of it is gibberish to me, but I can use a DVM, solder and replace part for part, and I really enjoy it when something works! Thanks all!marantz 4230caps.jpg
 
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Is it also off by the same amount on AM?

If it is, I would just move and reglue the pointer to a strong station.

If it's only FM it could possibly need the local OSC tuned but I wouldn't touch it. Maybe others will chime in on the proper method.
 
Be VERY careful if you are going to mess with the pointer. Those things break very easy. I know because I have done it. If you break the string plan on spending hours learning how it goes back on if it's you first time doing a restring. Good Luck!
 
Thanks Barney, I'll check the AM. not like I change stations much, so living with it is a very strong possibility!
 
Well it looks like the AM is spot on, so if setting it is too tricky and prone to screwing things up, I guess it's 'live with it' or take to someone who knows. Thanks all.

WP_20160723_22_15_33_Pro.jpg
 
Richs_Trains said:
Well it looks like the AM is spot on ...
Click to expand...

If that's the case, an adjustment to the FM OSC should correct the problem as mentioned in a previous post.
If you are going to try doing it yourself, mark the current position of the FM OSC pot first, tune to a strong station mid-dial, and use a plastic tool only to make the adjustment.
 
Its REAL touchy so give it baby turns or you will get lost. mark your starting point. Good luck. The worse you could do is strip or break a slug, then your screwed.
Make sure the tool fits perfectly and use it like your getting home too late after seeing your girlfriend and you have to pick the lock cause your wife changed it.
. Slow and careful and if it sticks, stop.. I busted one on my 2275, but fortunately it busted in a perfect spot. I used the wrong tool for the job and learned the hard way.
 
Here is a link to the service manual if you do not have it.

If you do not have a signal generator there is a work around. Tune in a station at the low end of the band and make sure the center tuning meter is centered. Then adjust the main tuning, moving the dial pointer in the direction needed to correct the reading so that the center tuning meter is off at by about half and adjust the inductor (L103 believe) to recenter the center tuning meter and just work you way up the dial until the pointer is correct at the low end of the band.

Do the same thing at the upper end of the dial (C187 I believe).

This is basically the same procedure as described in the service manual. It is just doing it in small steps and using the center turning meter (not the signal strength meter). The signal strength could be used instead, but you would need to use a weak station so as to not miss the peak of the adjustments because the meter reached full scale before the correct adjustment position is reached as you adjust the inductor and capacitor.

I do not know how far off the tuning dial is, but if it is a fair amount doing it this way in small steps will help you keep from getting lost with these adjustments and will get your very close even without a signal generator.

If the center tuning meter and the signal strength meter do not match when tuning in a station then more alignment is needed.
 
Okay guys, with all your help my 4230 is now perfect (knock on wood), one more question .... I have been collecting Marantz's for a while and have 20 or so units, as much as I would like to pay a skilled tech to recap these, at 300-400 a pop it is out of the question. I have started recapping the power supplies and amp boards (I don't have the test equipment or knowledge to get into phono, tuner, dolby or tone boards) in my units under the assumption that these circuits are the most used and the most likely to cause a catastrophic failure that would be difficult and expensive to fix. Am I right in this assumption and is this a good thing to help this equipment survive?
 
If you have 20 units then you have the Marantz fever and you're in it for the long haul.
Get some test equipment and the great guys here will tutor you all the way.

Bob
 
What would be the recommended list of test equipment and the order they should be purchased (since I can't afford too much at once)?
 
Echowars has a sticky in the diy forum on this with excellent info.

My top recommendations would be :
Good soldering station and a Hakko FR300 desoldering gun.
These 2 tools will go a long way to help eliminate any frustration or damage when replacing components,the main problem when first starting on this journey.

A couple of decent quality dvm's help when checking two things at the same time(say dc offset and bias or doing both channels' bias tests simultaneously).
A scope is helpful when troubleshooting and an absolute requirement for more involved tests.
To do distortion measurements and power output testing you'll need a good quality THD analyzer and audio signal generator and a resistor load bank.

FM alignment is a whole 'nother level of test equipment and experience.

There are lots of other items which are helpful timesavers but these are the basics .

Bob
 
Thanks Bob, Looks like I need about $1,000 extra dollars, so I need to stop buying old Marantz' and get some equipment!
 
The Hakko FR300 desoldering gun might be considered a luxury by some. But when I set up to try my hand at this stuff a few months ago, Bob made the recommendation and I bought one on Amazon. All I can say is, I wouldn't want to do this refurbishing work without it. It makes removal of components a snap. He told me I would thank him for the advice if I bought one, and I do every chance I get. :thumbsup:
 
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