SONY SQR 6650 Restoring the "Nicotine version"

[VintageDutch]

Hi all.. >>>>Hold on, sit tight, don't hold your breath.... This is gonna be a longggggggg read.>>>>

Got my Second SONY in beginning of April 2021.
Bought it for € 85,-- ex shipment (€30,--) from Germany to the Netherlands. Never heard it play... and I did not touch it.. It was from a Guy who I dealed with before and we have a trust relation on the Vintage HIFI gear...
He tells me what His findings are and ships and waits for me to pay on arrival...

On arrival....



After cleaning the fascia

From the sellers pictures I was prepared for some Nicotine. But this one had it really caked Nicotine and other filth on and in it...
During shipment sadly the power switch got a hit and did not survive.
I Hot wired it and ordered a original NOS ALPS switch from a Japanese supplier I found in a Treat on another forum.

After the hot wiring I was able to get FM reception on it on my Headphones and already I was stunned by the sound...(just on headphone!!)
I cleaned the switches, and replaced the Light bulbs (nearly all were dead) and It started to come alive...

Sadly the all but 1 VU Meters were all Stuck half way or at full scale. This did not vote to well for this meters..
Light bulbs replaced... see the VU meters "hanging" stuck.

This weekend, I got the Power switch in, so a good excuse to breakout that trusted Soldering iron.
The power switch was Quicky installed and all working fine.

After that I "attacked" the VU meters... So out came the tuning scale, exposing the vu meters "mounting"

I any one tried before these thing are stuck in there with double sided sticky tape from the 70ties... That stuff is hard... and could just as well be glued....
But nothing what a Little heat could not solve... and sure as anything... heating the black chassis steel up released the glue making it pliable again... and plop there it is...

Meters came out with no problem...
Marked and grouped the wires and simply cut them off.

Time to open up the Meters.... and this is what I found...

The VU meter scale is all bubbely...
No wonder the meters can not move...

After some fiddly stuff involving a Long "break of" type of Stanley knife between the Back side and the VU meter scale I was able to remove the scale carefully... Remember... these meter are very fragile..
Close up the VU scale looks like this


Clearly to see ... the scale is pretty warped... And I have a clue what has been going on....
The scale it self is glued with double sided sticky tape to the backside of the meter..
The regular light bulb heated the meter and the sticky tape.. The problem with that is that the tape after it got older It lost its flexibility and shrunk, but it was so hard stuck on that scale, scale actually did came a bit loose and "got pinched" by the tape resulting in bubbels..

SO basically we have a construction flaw...

I tried my luck on the good old interweb trying to find solutions, trying to find fitting replacements, I even fumbled around with a pair of AKAI tape deck meters I had laying around... No luck what so ever...
New Meters are just Way bigger so never will fit. there are no spares anymore... and no after market replacements.

SO... back to the drawing board.. first lets test the meters them self.. and I got very luck... all 4 are still moving after removal of the VU scale.!

Then the next question..... Do I feel lucky... Yes i did ..

SO I took a chance.... Pulled out the small blowtorch again.... and heated (from a distance) the scale a bit until I saw and feld It was a bit more pliable. I quickly put it down and cooled it with a piece of flat iron... Repeated thet proces on small sections... And it worked!
Both scales a now back nearly flat!

Left to do is cleaning those suckers up..... removing the last pieces of sticky tape...
The same on the meter body (in the pictures You can see them in the background) e try to bleach the VU meter body a bit)

Tomorrow get my some nice transparant glue and get it al together again.
I really think I got very very luck today, and that the Quadraphonic HIFI Restore Gods where on my side..

What I'm also gonna do is Wash that stinky Receiver from the inside with Aceton..... Man that thing still STINKS after nicotine.... Horrible..


Will be continued

 

[VintageDutch]

Episode 2 of the 4 VU meter repair...

To cut a corner in a much longer story ...... THEY WORK!!! All 4 of them!!


See them swinging

Totally happy..... now I can start repairing an RCA board, clean it... clean it some more..maybe clean it, recap re-solder, de-ox and did I mention cleaning?

For my information...... What do you guys and ladies use to un-stinkyfi and de-smellyfi nicotine soaked amps?
Is it a matter of a nice soapy bath and a two year drying period? Or simply start replacing parts where needed, re-solder the living daylights out it and Clean-up after wards with acetone? or rubbing alcohol?

 

[tcdriver]

Very nice work bringing that Sony quadraphonic receiver back to life. I like it.

 

[Doug G.]

It's not the nicotine that stains/coats, it's the tar.

Doug

 

[VintageDutch]

Very nice work bringing that Sony quadraphonic receiver back to life. I like it.

Thanks for the kind words.... One does his best.... I just liked (and have) it small brother STR6046, and could not resist that Beastly smelly PROJECT
Might have found a smell resolving solution.... being Isopropanol Spray ... never used it but the manufacturer promesses it will clean PCB's as wel... and devolves very good.

 

[VintageDutch]

It's not the nicotine that stains/coats, it's the tar.

Doug

SO getting the tar off the smell will go aswell?

 

[Doug G.]

Well, I guess that's another issue. Years ago where I worked, I would use 409 brand cleaner to remove stains from old computer monitors. I don't remember if it was the industrial version of the cleaner or just the regular version but when I sprayed it on the surface, the stains literally ran down the surface, immediately loosened without scrubbing. It seemed it pretty much removed the smell, too.

Doug

 

[VintageDutch]

We don't have the 409 cleaner in the Netherlands... But I willing to test and test...

Thanks for the pointer anyway!

 

[VintageDutch]

Such a delight to work on my SQR 6650

Got the metering done, Recapt the supply board (all but two caps witch I did not have in stock). Also Recapt the decoder Board... replaced the Stereo indicator light bulb and the Scale point Lightbulb...all is glowing now.....

Got the "new" old Knobs in today. Only have to restore 4 of my original push buttons.. starts to loook like a "normal" receiver again....Cleaned all the facia parts... and hope to receive the cleaning spray in today to finnaly get that smell out of house!

Gonna make-up a shopping list to recap the power amp... and start inventory on the Preamp board caps...and the Reciever board caps.

Also want to replace the speaker terminals... Never liked the wirescrew speaker connections...As last I will repair or replace the broken tape deck RCA plug connector board....

In the end this repair and restoration goes way faster then I could have expected...I think it is all about the fun..

Can't wait to get it in my living room... 4 channels connected... dream dream dream.....

 

[Pat Bateman]

Such a delight to work on my SQR 6650 View attachment 2217037

Got the metering done, Recapt the supply board (all but two caps witch I did not have in stock). Also Recapt the decoder Board... replaced the Stereo indicator light bulb and the Scale point Lightbulb...all is glowing now..... View attachment 2217038

Got the "new" old Knobs in today. Only have to restore 4 of my original push buttons.. starts to loook like a "normal" receiver again....Cleaned all the facia parts... and hope to receive the cleaning spray in today to finnaly get that smell out of house!

Gonna make-up a shopping list to recap the power amp... and start inventory on the Preamp board caps...and the Reciever board caps.

Also want to replace the speaker terminals... Never liked the wirescrew speaker connections...As last I will repair or replace the broken tape deck RCA plug connector board....

In the end this repair and restoration goes way faster then I could have expected...I think it is all about the fun..

Can't wait to get it in my living room... 4 channels connected... dream dream dream.....

Hey, I just scored one of these for not much (this plus 4* EPI mini tower speakers and a National turntable for $100).

I actually figured out the same issue with the VU meters and all of mine work too, not bad for a 45ish year old unit.

Questions for you-

Did you ever figure out a replacement for the old light bulbs?

Did recapping make enough distance to be work the hassle?

Do you have a view about how safe it is to use delicate speakers with this unit? I assume it has no protection built in...

 

[VintageDutch]

Hey, I just scored one of these for not much (this plus 4* EPI mini tower speakers and a National turntable for $100).

I actually figured out the same issue with the VU meters and all of mine work too, not bad for a 45ish year old unit.

Questions for you-

Did you ever figure out a replacement for the old light bulbs?

Did recapping make enough distance to be work the hassle?

Do you have a view about how safe it is to use delicate speakers with this unit? I assume it has no protection built in...

Hi Pat,

Yes.. I did... I replaced the lightbulb with LED bulbs. Pretty straigh forward te replace..
I used Warm White.. I must say... these are pretty close to the originals but generate more light...(not brighter)
They stay almost cold... so no more warping of the tender plastics...
Down side is the produce more light!!!! So I'm planning on a small voltage regulation when my new home and workshop are done and me back in Audio action.

Recapping is also easy... Had no problem at all.. Just be sure to have de-soldering litze or a de-solder pump.

From the top of my mind.... indeed there is no speaker protection circuit... SO in any DC on the out situation you are screwed ... on the other hand.. It is not a hefty power house... 4 x 12 watt I think it is....You will not destroy any speaker during normal use.

I would advice..... Take your time.....Let the amp run with out any signal for some days... on a 8 ohm 10 watt resistor per output... While measuring for DC.
Use a some old simple cheap speakers you can spare to blow up for the first audio testing... run it for days.... not problems??? then switch to your sensitive speakers

Good luck buddy with this Beauty... sorry I re-acted this late....I'm in the middle of home renovation the last 4 mounth...But let me know where you are at with this beauty..

questions? just ring my bell

 

[Pat Bateman]

Hi Pat,

Yes.. I did... I replaced the lightbulb with LED bulbs. Pretty straigh forward te replace..
I used Warm White.. I must say... these are pretty close to the originals but generate more light...(not brighter)
They stay almost cold... so no more warping of the tender plastics...
Down side is the produce more light!!!! So I'm planning on a small voltage regulation when my new home and workshop are done and me back in Audio action.

Recapping is also easy... Had no problem at all.. Just be sure to have de-soldering litze or a de-solder pump.

From the top of my mind.... indeed there is no speaker protection circuit... SO in any DC on the out situation you are screwed ... on the other hand.. It is not a hefty power house... 4 x 12 watt I think it is....You will not destroy any speaker during normal use.

I would advice..... Take your time.....Let the amp run with out any signal for some days... on a 8 ohm 10 watt resistor per output... While measuring for DC.
Use a some old simple cheap speakers you can spare to blow up for the first audio testing... run it for days.... not problems??? then switch to your sensitive speakers

Good luck buddy with this Beauty... sorry I re-acted this late....I'm in the middle of home renovation the last 4 mounth...But let me know where you are at with this beauty..

questions? just ring my bell

Thanks for the reply!

My question about lights wasn't clear - do you have a part number you can give me, or a link, to what you used as a replacement?

I actually have run the amp pretty successfully with the speakers I got with it (the EPIs mentioned above) and no signs of trouble. I have some carefully restored Kef Coda Is that would be a good match I think, but that makes me nervous as T27 tweeters are easy to kill and hard to come by... I will see if I get brave enough. I also have some Rogers and Acoustic Research speakers that might pair well.

I love the look of this thing, but I'm a sucker for Sony stuff generally.

 

[Stonesman]

I have a STR 8750 and all but 1 of the lamps are out. Did anyone ever find a replacement supplier or ebay seller? I pulled out the bulb and it looks like the "nipple" bottom just has the connectors built in? I'm new to actually trying to repair some of my vintage equipment (we all have to start somewhere). It sure will be much better if the blubs simply pop back into the grommets.