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Fixing a legend.....


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#1 blu_fuz

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Posted 20 September 2013 - 12:23 PM

I bought this Panasonic RX-5350 knowing there was some kind of issues with it, but didn't know exactly what. After getting it here, overall the condition is good. Needs a cleaning/detail and is missing the battery door.


The problem is after testing it out, the capacitors might be dried up causing 'motorboating' which is a term used to describe the sound that comes from electronics with bad components.

After de-oxing the knobs and switches, this is what I have to start with.



As you can see, I do get sound even from L/R with the Ipod, which is a good sign that the amps are OK. The cassette does play/ff/rw/rec/etc. from what I can tell including the tape counter. All the parts move and are belted at least.



This thread is to document the work involved to re-cap a monster like this, maybe a little troubleshooting, and some tips/tricks. Hopefully there is a happy ending! :D


If there truely are 130+ capacitors in this, 2 minutes to replace each (kind of slow, but figuring worst case) best case scenario working on it straight through, no breaks, and saying I have all the correct replacement caps sitting here, could easily take me 4.5 hours!!!!


Worth it? Hell yeah ;)



Here is my paperweight today:

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#2 jimmyjimmy19702010

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Posted 20 September 2013 - 01:52 PM

She 's a fine looking machine - you've definately scored a worthy box to repair!

Good luck,

James... :-)

P.S. I take much longer than 2 minutes per cap!! ;-)

#3 kraftmatic

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Posted 20 September 2013 - 02:20 PM

Definitely not my favorite kind of motorboating... 



#4 BoomboxLover48

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Posted 20 September 2013 - 04:33 PM

I should say 5350 the World's Best sounding box! The king of Kings.... :hooray:  :hooray:  :hooray:

 

Congratulations! It is in excellent cosmetic condition!



#5 Lasonic TRC-920

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Posted 22 September 2013 - 08:30 PM

Bro, this is one of those radio's if you F it up, your going to catch the wrath of the whole site! It looks SWEET man, you did a great job!



#6 blu_fuz

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Posted 23 September 2013 - 08:16 AM

I hear ya Chris :lol:. As long as I take my time, label caps and note the direction of polarity, it shouldn't be too bad. I promise to take care of it!

 

I just finished the stereo install in my truck so now I can setup a station in the garage to start working on the 5350. I'm actually excited to see what I can fix.

 

Obviously I will start looking for something easy to fix first. If nothing is obvious then I will go into full fix mode and get my capacitors ordered.



#7 redbenjoe

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Posted 23 September 2013 - 09:35 AM

think of your pride and joy when you complete all this -   :drool:



#8 blu_fuz

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Posted 23 September 2013 - 09:37 AM

Thanks Ira ;)



#9 BoomboxLover48

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Posted 23 September 2013 - 12:00 PM

Be patient! Don't do any calculations like 2 minute per capacitor.

Trust me! I've done full recap on 5 or more units and it takes much much much longer time.

Going back and forth looking for the right leads is more time consuming and also the "solder sucking" job to make the holes clean.

 

Good Luck Joe! :-)

 

Like Ira said you will now have a great unit when it is all done right! :-D



#10 BoomboxLover48

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Posted 23 September 2013 - 12:02 PM

think of your pride and joy when you complete all this -   :drool:

That is a very motivating comment. I like it.... good job Ira! :bow:  :bow:



#11 blu_fuz

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Posted 23 September 2013 - 01:55 PM

Be patient! Don't do any calculations like 2 minute per capacitor.

Trust me!

 

 

Oh don't worry, I won't be rushing through this to hit any kind of record, or to do any certain amount of caps per minute. This will be a pretty slow drawn out repair. I bet I might only do 10 caps in one sitting before I get interrupted with "real life" :lol:.

 

That's another reason I have to setup in the garage because it won't be a weekend warrior project.



#12 k2j

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Posted 23 September 2013 - 03:31 PM

Nice one Joe.  I used to dislike the looks of that model, but now I'm dying for one.  Of course I passed one up locally years ago for pennies.  Ooof dah!

 

Enjoy the recapping!



#13 =ml=

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Posted 24 September 2013 - 11:54 PM

I didn't know Ira was broken ;)

 

Go!

 

=ml=

 



#14 blu_fuz

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Posted 03 January 2014 - 10:40 PM

Finally opened it up tonight. Found some dry solder joints and some green corrosion on a few electronic components. No blown or bulged caps that I could find......

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#15 Superduper

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Posted 03 January 2014 - 11:24 PM

Electrolytic caps blow when over voltage (or reversed) and bulge when overheated or over voltage. However on older electronics, the issue is primarily dried out electrolyte within the caps which probably won't show any external physical signs. In other words, while blown or bulging caps is a good indicator that the component has failed, the lack of physical abnormalities should not be taken to mean that the opposite is necessarily true.

#16 gsbadbmr

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Posted 03 January 2014 - 11:58 PM

The 5350 is a killer box, i hope you get it back to normal :thumbsup:



#17 =ml=

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Posted 04 January 2014 - 01:40 AM

Finally opened it up tonight. Found some dry solder joints and some green corrosion on a few electronic components. No blown or bulged caps that I could find......

attachicon.gif0103142107.jpg

 

Nice, a date stamp! :yes:

 

* 8 (1-12) month
* 2 (0-9; 1980-1989) year
* 2 (0-3) first day digit
* 4 (0-9) second day digit
* ? (1-3) work shift 

 

So this part was molded on August 24, 1982. :-)

 

Do you mind if I add it to http://www.pinterest...s/date-stamps/?

 

Good luck with resto!
 

Go!

 

=ml=



#18 Ken

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Posted 04 January 2014 - 07:02 AM

Good luck, Joe.  Like Ira said, just imagine your pride 'n joy all finished and sounding sweet.

 

Oh, and remember: The bigger the blob, the better the job.  Now, let the soldering begin!



#19 blu_fuz

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Posted 04 January 2014 - 08:05 AM

ML, yeah buddy you can add it to the registry of date stamps. It was a '2nd' shift built box.

Norm, for sure about the dried up caps. I was searching for anything obvious that could be the culpret. I'm going to take inventory on the caps so I can get new ones ordered.

I was suprised at how easy it is to get to the main board, quick connectors, and plenty of room inside the 5350. I'm excited to get working on it ;).

Thanks Kenpat, I hope I can get it singing again.

Ps, there were 4 pins on the function switch that had only a partial blob of solder. 1 of the pins I was able to see it was wiggling free of the solder. Not sure why, maybe someone was in this box before...... who knows.

#20 BoomboxLover48

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Posted 04 January 2014 - 08:31 AM

I agree there is lots of room to work on and easy to remove the boards but replacing any of those pots is so hard to work on.

Tuning chord is on the front plate where the pots mounted. Without removing the tuning chord it seemed practically impossible to work on them.

 

Good Luck Joe!

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#21 Lasonic TRC-920

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Posted 04 January 2014 - 12:44 PM

ML, yeah buddy you can add it to the registry of date stamps. It was a '2nd' shift built box.

Norm, for sure about the dried up caps. I was searching for anything obvious that could be the culpret. I'm going to take inventory on the caps so I can get new ones ordered.

I was suprised at how easy it is to get to the main board, quick connectors, and plenty of room inside the 5350. I'm excited to get working on it ;).

Thanks Kenpat, I hope I can get it singing again.

Ps, there were 4 pins on the function switch that had only a partial blob of solder. 1 of the pins I was able to see it was wiggling free of the solder. Not sure why, maybe someone was in this box before...... who knows.

 

Can you post where you are ordering the caps from?



#22 blu_fuz

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Posted 04 January 2014 - 12:51 PM

Probably was going to try and order Panasonic brand caps off ebay. I havnt really looked into it much but Norm gave me some ideas.

#23 Lasonic TRC-920

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Posted 04 January 2014 - 01:23 PM

OK, Cool



#24 skippy1969

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Posted 04 January 2014 - 02:01 PM

SWEET!!!! Good luck Joe,you can do it!  ;-)  :-D



#25 char

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Posted 04 January 2014 - 02:43 PM

Nice, a date stamp! :yes:

 

* 8 (1-12) month
* 2 (0-9; 1980-1989) year
* 2 (0-3) first day digit
* 4 (0-9) second day digit
* ? (1-3) work shift 

 

So this part was molded on August 24, 1982. :-)

 

Do you mind if I add it to http://www.pinterest...s/date-stamps/?

 

Good luck with resto!
 

Go!

 

=ml=

YOU must to add manufactures plants on asia region site page for boomers :yes: :clap: :hooray: :rock:according to dis



#26 blu_fuz

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Posted 04 January 2014 - 04:21 PM

Had some time during the new babies nap to get a cap inventory. I marked a reference point on each cap on the same side. This will be important during the removal/install of the new caps.

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#27 Superduper

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Posted 04 January 2014 - 04:49 PM

Low voltage (6.3) caps were chosen by manufacturers for cost efficiency reasons, but in my opinion, those are too low for any kind of reasonable margin given the low cost of caps today, especially the low value ones. I generally go 25v (and even 50 or 100v) on the small ones. My point being if you have 4 different voltage caps with the same uF rating, (i.e. 1uf) then just order the same higher voltage rating caps all around for the entire lot and don't worry too much about matching voltage. Higher gives you better margin and longer service life, especially in cases where operating voltage isn't far below the caps volt rating.

#28 Superduper

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Posted 04 January 2014 - 04:52 PM

As an example, I see 33uF caps on your list in 10, 16, and 25v. Just get the 25v ones for all applications and be done with it.

#29 blu_fuz

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Posted 04 January 2014 - 04:56 PM

^ dude great tip, that will save me hassle of finding exact matches when it isn't really needed. Thank you Norm ;)

#30 BoomboxLover48

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Posted 04 January 2014 - 06:11 PM

As an example, I see 33uF caps on your list in 10, 16, and 25v. Just get the 25v ones for all applications and be done with it.

 

As an example, I see 33uF caps on your list in 10, 16, and 25v. Just get the 25v ones for all applications and be done with it.

Provided the size fits! I knew this and ordered caps at reasonably higher voltages but they were pretty large in size though! If only you want them to sit on their butts if not they will have to stand up on insulated feet. No big deal!  :-D