My Pro-197 that I bought...heavily used...seems to have no sound. I've seen in previous forums this is a known issue with this model. Any suggestions to fix it? A couple love taps to the top worked once, but it quit working again. No luck in the audio out port, either.
Pro-197 works on and off
- Thread starter mocofeed
- Start date
doctordialtone
Member
2 suggestions.
1) Run it with external speakers, like PC speakers.
2) Spray contact cleaner on the contacts. They're probably oxidized.
Sometimes just inserting a plug in and out will clear the dirty contacts
tvengr
Well Known Member
Dirty contacts on the headphone jack will mute both the internal speaker and external speaker jack. Try inserting and removing a plug in the headphone jack numerous times. I have seen a couple of cases where the TDA1905 audio output IC shorts out. If you remove the cover, there are a couple of large resistors around it which will be discolored due to excessive current when the IC shorts. The circuit board will also be discolored. If that is the case, the IC will be extremely hot. Do not touch it with power applied unless you enjoy the smell of burning flesh. The IC is replaceable by a NTE7000. Do not attempt to make the repair yourself unless you are used to working on circuit boards. The foils on the board are very fragile. Also check the solder connections on the external speaker jack while the cover is removed.
Forgive me as I'm a novice, but when you say spray contact cleaner, what exactly should I spray? I'm not too familiar with scanners outside programming and software. The hardware always stumped me. I.e. where on the scanner should I spray?
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wtp
Member
just test it with the computer speaker thing first.
wtp
Member
there could be corrosion/oxidation in a couple of spots.
where the plug makes contact with the metal, and where the plug separates the contacts that send the audio to the speaker.
when you insert the plug it is the area with the arrows in this pic.
the left side is where the sound travels through the jack.
and then on the right is where they get separated and anything that keeps it from making full contact with the plug out will cut out sound to the speaker.
where the plug makes contact with the metal, and where the plug separates the contacts that send the audio to the speaker.
when you insert the plug it is the area with the arrows in this pic.
the left side is where the sound travels through the jack.
and then on the right is where they get separated and anything that keeps it from making full contact with the plug out will cut out sound to the speaker.
wtp
Member
i also see a headphone jack in the front and an external speaker in the rear.
wtp
Member
i would take the radio apart and use the cleaning spray, on both, just using a tube would put most of it in the radio.
and just spraying the outside does not do much.
and like was said before, then you put a plug in a number of times to make and break connections and clean the contact area of the plug/jack.
or try computer speakers in the headphone jack.
i have a very old pro2004 that has an amp sitting on it with a speaker on top as the audio out is broken.
i think i paid $5 for the amp. and had the speaker. it just looks big and commercial like.
and just spraying the outside does not do much.
and like was said before, then you put a plug in a number of times to make and break connections and clean the contact area of the plug/jack.
or try computer speakers in the headphone jack.
i have a very old pro2004 that has an amp sitting on it with a speaker on top as the audio out is broken.
i think i paid $5 for the amp. and had the speaker. it just looks big and commercial like.
wtp
Member
kind of like this...
but just one of them
sure it looks different, but it works !
sure it looks different, but it works !
doctordialtone
Member
Spray it in the jack that's causing the problem.
You can spray a good amount into the hole - it won't hurt anything - then push a plug in and pull it out numerous times.
tvengr
Well Known Member
The fact that neither the internal speaker nor an external speaker work leads me to believe that it is the headphone jack or an audio amp problem. It is usually the contacts on the headphone jack are not closing and are muting both the internal and external speakers.
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Could also be an open volume pot.
