stalker 9 dx no audio from speaker

[buzzby]

Radio Make and Model: stalker 9 dx
PCB Number: pc-893aa
PLL Number: not sure can find it on set
Test gear available: test meter
Symptoms: no sound from the speaker

What is working: everything checks out

What has been tried: done some circit tests

Did it suddenly happen ?: yes when i was talking to a friend
Anything else that may be of help?: My set was working brill was talking to a cb mate one day and the sound stopped i have done all the checks everything works 100% it keys up and it talks and recives a signal because the needle moves when i do checks with another set, The mike works brill i tested it with another cb, can someone tell me which audio part and its number to do some checks please any help would be (appreciated) thanks

[zodiac]

Does the audio work on PA ?.
If not then check C159, 10v @330uF and C161, 10v @47uF, better still change both for 16v capacitors at the same uF value. IC507 is the audio chip.
Dave.

[buzzby]

Does the audio work on PA ?.
If not then check C159, 10v @330uF and C161, 10v @47uF, better still change both for 16v capacitors at the same uF value. IC507 is the audio chip.
Dave.

ST9 FDX audio.JPG

Thanks very much for your help) i done those checks c159 and c161 all checks out, i done checks with muilti meter tester ,i will have to get a ic507 audio chip; it run's very hot even when i was doing the checks so there must be a short in the chip thanks again dave

[zodiac]

If you have any problems getting a new audio chip KCB (Knights)in the UK have them.
That's what happens when the radios been cross poled as well, It's the first IC to go pop when the idiot diode fails.
Dave.

[buzzby]

If you have any problems getting a new audio chip KCB (Knights)in the UK have them.
That's what happens when the radios been cross poled as well, It's the first IC to go pop when the idiot diode fails.
Dave.

yes the diode at the back of the set is blown and some guy has solderd a replacement onto the pcb and it looks an awfull soldering job on which i had to tidy up.many thanks dave for your help i will get onto knights about a replacement today and will let you know how things go with my stalker

[buzzby]

If you have any problems getting a new audio chip KCB (Knights)in the UK have them.
That's what happens when the radios been cross poled as well, It's the first IC to go pop when the idiot diode fails.
Dave.

yes the diode at the back of the set is blown and some guy has solderd a replacement onto the pcb and it looks an awfull soldering job on which i had to tidy up.many thanks dave for your help i will get onto knights about a replacement today and will let you know how things go with my stalker

hi dave would you have a part number for ic507, knights needs it to check to see if thay have them in stock thanks again dave .ragards philip.

[zodiac]

Yes,
It's on the schematic above, UPC1182H.

[buzzby]

Yes,
It's on the schematic above, UPC1182H.

Thanks dave i should had seen that many thanks philip

[buzzby]

Yes,
It's on the schematic above, UPC1182H.

Thanks dave i should had seen that many thanks philip

hi dave i have just noticed that i have power to the speaker 0.07v and when i switch the rig on; the speaker sounds as it would when i power up the rig, would a squelch malfuncion cut the audio to the speaker. many thanks philip.

[zodiac]

Yes it would mute the audio.

[buzzby]

Yes it would mute the audio.

was wondering if there was a part where i could disconnect the sq just to see if it was it, thats causeing my trouble .thanks philip.

[zodiac]

Can you hear a pop in the speaker when you turn the squelch control up and down, if you can then the squelch is working fine.

[zodiac]

These are the voltages on the audio chip pins starting at the back of the radio in FM mode.
13.5
12.3
7.0
0.9
2.11
2.9
0.9

[buzzby]

These are the voltages on the audio chip pins starting at the back of the radio in FM mode.
13.5
12.3
7.0
0.9
2.11
2.9
0.9

i done those checks and mine does not look the same, and the sq does nothing when you turn the switch up
13.7
12.4
4.85
0.02
5.76
7.21
4.54
i think going with these checks that this output is fryed... was wondering what your opinion was dave or is it a blown part in the set
Thanks dave you are being very helpful and it is very much appriciated regards philip

[buzzby]

These are the voltages on the audio chip pins starting at the back of the radio in FM mode.
13.5
12.3
7.0
0.9
2.11
2.9
0.9

i done those checks and mine does not look the same, and the sq does nothing when you turn the switch up
13.7
12.4
4.85
0.02
5.76
7.21
4.54
i think going with these checks that this output is fryed... was wondering what your opinion was dave or is it a blown part in the set
Thanks dave you are being very helpful and it is very much appriciated regards philip

my tx output has gone now as well the TA473 i think the damp has got to this set and have it stored in with the hotpress to dry it out hope this set is fixable would anyone know if cobraworx would service this set and bring it back to life i already asked and they have not yet got back to me

[zodiac]

Phil,
You have a PM.
Dave.

[buzzby]

Phil,
You have a PM.
Dave.

thanks dave ill check it out now