Radio Shack Pro 433 Pro-433 Audio Problem

[hamradio2009]

Today I turned on my Radio Shack Pro 433 and there was no audio. I reset the scanner multiple times and still nothing. It shows a receive frequency but nothing on the audio. Tried external speaker, headphone jack, etc, nothing. Any ideas?

 

[Evert]

You need to give a lot more detail about what you did, your previous experience with this scanner and where you are.

If you just did a reset, there would be no frequencies stored.

If you continued on to load the 150 preprogrammed frequencies, maybe none of those are active in your area.

Are you new to using Radio Scanners? Do you know the basics about setting squelch, turning banks on/off, frequency lockout, etc.?

What is the situation when " It shows a receive frequency but nothing on the audio" - operating in scan mode, manual mode or what?

 

[hamradio2009]

pro433 problems

After unplugging the unit for a while (30mins) it let out a loud squelch tail when I plugged it back in. Could it be some sort of capacitor on the audio side of the unit?

I selected the weather search and it stopped on a station in my area. No audio but the scanner is showing an active frequency. I played with the squelch and volume knobs. Reduced the squelch to min and I can hear a faint audio white noise when I turn the volume all the way up.

Experience with scanners is some what extensive. Owned 15 or so over the years. Currently own 4 including a BCD396xt. Also an experienced ham radio operator (12 years) and electrical engineer. For some reason I think it is a capacitor based upon the fact I unplugged it and then plugged it back in. This would give some sort of audio cap time to discharge and then recharge quickly before losing the voltage across the terminals. This is just a idea and I am open to suggestions. Any help would be much appreciated.

 

[Evert]

Geez don’t they teach EEs Problem Solving 101? Or did you just skip the lecture on Problem Definition?

 

[hamradio2009]

I am not sure what is confusing regarding my question. I have outlined various things I have tried to no avail. Do you have any suggestions?

 

[DickH]

I am not sure what is confusing regarding my question. I have outlined various things I have tried to no avail. Do you have any suggestions?

It's possible the external speaker jack has been damaged. Try inserting and removing the external speaker plug several times. If that's not the problem a component in the squelch or audio circuits has blown.
Now here's the bad news. Radio Shack will not even acknowledge the PRO-433 (and the PRO-528) ever existed, let alone offer any support.

 

[Evert]

I am not sure what is confusing regarding my question. ?

I was referring to your first post in this thread. The information given in your second post would have been a much better starting point.

And sorry, but I dont have any suggestions. Dick H and gmclam are much better troubleshooters than I am, so they may be able to help you find the problem. But I wonder if you don't have some test equipment that you could use find out if the suspect capacitors are defective?

 

[DickH]

It's possible the external speaker jack has been damaged. Try inserting and removing the external speaker plug several times. If that's not the problem a component in the squelch or audio circuits has blown.
Now here's the bad news. Radio Shack will not even acknowledge the PRO-433 (and the PRO-528) ever existed, let alone offer any support.

More bad news. The PRO-433/528 and the PRO160/162 scanners are Uniden, Japan products made for Radio Shack. Don't bother to ask Uniden, America about them because they will give you the same story as Radio Shack.

I can offer you a glimmer of hope by giving you the Tokyo address of Uniden, Japan, so the next time you're over there you can drop in and try to get them to help. I can also tell you the nearest subway station and the best door of which car in the train to exit.

 

[hamradio2009]

Thanks for the information. I will check out the speaker jack and try to troubleshoot the audio circuit. Yea I was looking for a schematic online and apparently they are hard to come by because everyone is scared you might modify the unit to receive cell phones in the 800 band (which are no longer used).

 

[zzdiesel]

My 433 started having this exact problem. Everything seems to be working except the audio circuit. I'm about ready to dump it in file 13.

 

[DickH]

My 433 started having this exact problem. Everything seems to be working except the audio circuit. I'm about ready to dump it in file 13.

Have you tried plugging in headphones to see if they work? If they work, the speaker may be bad. If they don't work, unplug and plug it in several times. The speaker jack could have become dirty or corroded and that will clean the contacts.
If none of the above works, I can e-mail you the schematic and the troubleshooting steps from the Service Manual. Let me know.

 

[zzdiesel]

Thanks, but I have a handicapped hand & I'm unable to work with electronics. It did work with headphones. Then I unplugged them & the speaker worked for a little while and then quit again.

 

[nanZor]

Be sure to check the internal ribbon cables for proper seating / alignment.

I brought back a 2055 that way, and even had to clean oxidized gunk off the ribbon cable ends. Two of the ribbon cables weren't even locked in.

 

[zzdiesel]

Thanks. I'll check into it.

 

[mruell_1]

Pro-433 Schematic

Have you tried plugging in headphones to see if they work? If they work, the speaker may be bad. If they don't work, unplug and plug it in several times. The speaker jack could have become dirty or corroded and that will clean the contacts.
If none of the above works, I can e-mail you the schematic and the troubleshooting steps from the Service Manual. Let me know.

Hi DickH
I have a pro-433 with a audio problem will you email the schematic to me, that would be a great help.

Thanks

mruell_1

 

[DickH]

Hi DickH
I have a pro-433 with a audio problem will you email the schematic to me, that would be a great help.

Thanks

mruell_1

Check your Yahoo e-mail.

 

[mruell_1]

I had to check my spam file and there they are.

Thank you for your help.

mruell_1

 

[ProphetPX]

pro-433 audio problem

Have you tried plugging in headphones to see if they work? If they work, the speaker may be bad. If they don't work, unplug and plug it in several times. The speaker jack could have become dirty or corroded and that will clean the contacts.
If none of the above works, I can e-mail you the schematic and the troubleshooting steps from the Service Manual. Let me know.

I ALSO have a pro-433 with the aforementioned audio problem.
will you (DickH) please also email the schematic to me, too?

i may have the same problem as the other person had. i am not getting any audio, even after resetting the scanner twice.

TIA

--Ryan

 

[DickH]

I ALSO have a pro-433 with the aforementioned audio problem.
will you (DickH) please also email the schematic to me, too?

i may have the same problem as the other person had. i am not getting any audio, even after resetting the scanner twice.

TIA

--Ryan

I can't send info to everyone on RR who owns a 433. I suggest you do as I did and get the Service Manual from Radio Shack.
12449039 MANUAL SERVICE 20-0433

 

[ProphetPX]

pro-433 audio problem

I can't send info to everyone on RR who owns a 433. I suggest you do as I did and get the Service Manual from Radio Shack.
12449039 MANUAL SERVICE 20-0433

wait a minute... i do not understand? you sent it to the other guy?
why not to me too? i was asking politely.