Galaxy DX33HP2 problems

[Derrick Walls]

I'm working on a galaxy dx33hp2. It has a tda2003 audio chip in it. Problem I'm having with it is I remove c156 and the recieve audio will come back but it is low. I can replace it with a new part and the audio will go away. I still have deflection on the meter and a signal to the input of the audio but no audio. Also the audio in TX is low (20% or less). I need help on this. Replacing the audio chip yielded no results.

 

[sonoma]

have you verified you still have full output from the finals. a few years ago I had one that the mosfet final shorted and killed the RX. if they are good only thing I can say is check the rest of the parts tied to tr42 the same circuit c156 is in.

http://www.cbtricks.com/radios/galaxy/dx33hp2/graphics/dx_33hp2_sch.pdf

forgot to tell you to verify tr42 is switching also. it may have gone bad plus more parts in the same circuit could be bad.. wish I could give better info as to what part is bad but not much luck doing that.

 

[Derrick Walls]

I made a typo earlier it is c146 instead of c156

 

[sonoma]

check D77, D80, and tr38. they are all right in the audio circuyit that can give you a problem. D77 is the most common part that can act up in that area.

 

[Derrick Walls]

Had no luck there all those parts are good

 

[Derrick Walls]

I did notice while keying and unkeying the radio the recieve would come in for a split second. So I went on to check voltages at tr36 and tr37 since I checked tr38. Voltages werected good at these points

 

[Derrick Walls]

Also noticed the audio chip is getting hot

 

[sonoma]

check D77 and D80 . D77 will kill receive also plus TX at times. need to verify the other parts are good in the circuit.

 

[Derrick Walls]

Ok. after losing my mind and half my hair I finally came back to the audio chip and determined the part i replaced was defective then replaced it and now i have receive audio again. Now I still have no tx audio. According to the oscope I have good audio out of IC4.