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 Post subject: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Mar Sat 31, 2018 10:34 pm 
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Joined: Mar Sat 31, 2018 9:55 pm
Posts: 3
Newbie here. My wife was given an RCA Victor VHT66S and everything seems to work but I have no sound coming out of one speaker and very low sound coming from the other. When I turn up the volume all the way up, you can barely hear it.

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NOTE: The same symptoms appear whether you are playing a record, Radio AM, FM or FM Stereo.

There is a dial setting to switch from internal speakers to external speakers, to both or to headset. When I switch to headset, and I plug in a set of headphones, the same symptom: No sound out of one side and very little sound out of the other.

The internal speaker set is good as I tested the it with an external source.

I read that capacitors are the primary cause of failures, so I replaced 4 in the power unit as noted below. However, that didn't fix my problem.
Anyone has any pointers as to where to go from here?

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I have purchased the schematics, but I need some guidance


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 Post subject: Re: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Apr Mon 02, 2018 2:06 am 
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Joined: Aug Sun 23, 2015 6:01 pm
Posts: 950
Location: South Jersey East of Philly
Before we can advise you...Do you have experience working on Solid State or tube radio/phono circuits?


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 Post subject: Re: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Apr Mon 02, 2018 2:59 am 
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Joined: Mar Sat 31, 2018 9:55 pm
Posts: 3
Tbirdkid wrote:
Before we can advise you...Do you have experience working on Solid State or tube radio/phono circuits?


Unfortunately, I don't have that experience, so this is venturing into the unknown for me. I have spent quite some time looking at the diagrams and checking voltages at different spots to make sure they coincide with the specs. But everything so far has been at the AMP chassis.

I have found two additional bad capacitors in the AM/FM tuner, so I guess, I'll replace those. I did find them in the diagram as well (see below).
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A little zoom in
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So, as you can see, my troubleshooting isn't much of finding the symptom and going to a specific area. All I have been doing is taking measurements (Resistance, Capacitance and voltages) and comparing them to the specs.


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 Post subject: Re: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Apr Mon 02, 2018 6:31 am 
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Joined: Aug Sun 23, 2015 6:01 pm
Posts: 950
Location: South Jersey East of Philly
I guess since you have started with the caps, the electrolytics usually give the most problems...So you are on a reasonable repair trail to replace the bad ones. I usually do a quick dirty check of all the electrolytic caps by taking alligator clips, observe polarity, and attach a close or equal value know good cap in parallel with the cap in the set..if the gain goes up you have found a bad cap...if no change, the existing cap is probably good. Remember, they hold a charge, so discharge them before touching them after you finish the test. This is a transistor set so you shouldn't see much above 45 volts anyway.
Since your problem is on all functions, the main amp (I think it may be separate chassis) caps should be checked as well as the ones in the tuner chassis. If the problem still exists after checking all caps...time to regroup and figure the next step to go to. Make sure you are getting good spec voltages out of the power supply also.


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 Post subject: Re: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Apr Tue 03, 2018 6:16 am 
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Joined: Mar Sat 31, 2018 9:55 pm
Posts: 3
Success!!!!! :D Check here https://youtu.be/Jj64jwkU9Do

I replaced the two capacitors in the AM/FM Tuner chassis and while I was at it, I replaced an additional four that were shown to be under performing.
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I was thrilled when I heard sound coming out of both speakers. I also upgraded the unit with a wireless bluetooth module, so I can place music via BT. I left the module accessible through the back for pairing to other devices.

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https://youtu.be/Jj64jwkU9Do


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 Post subject: Re: Newbie Here - Low Sound RCA Victor VHT66S
PostPosted: Apr Thu 05, 2018 1:58 am 
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Joined: Jan Wed 16, 2013 12:04 am
Posts: 1510
Location: 77001
Good job !
It does feel pretty special when these
old hi-fi gals are performing optimally again.
Hotwax


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