rci2995dx low volume issue [help please]

[dirtyjob]

I have a rci 2995 dx, not the dxcf but the dx model, It works great except all of a sudden the volume is very low on rx, both am and ssb i have to crank the volume all the way to hear people now. What is the problem with this, does the same with headphones, i have to crank the volume knob. Anyone have any information on this issue ? Thanks in advance. Im thinking it may just be IC TA7222AP ic7 any thoughts ?

 

[nomadradio]

There is more than one thing that can break and do this. I would suggest you plug an external speaker into the PA jack and select PA mode. If you get deafening mike audio from the external speaker, the TA7222P chip is okay. And if it flunks this test, maybe your audio chip really does have a problem.

If it passes, this leaves four more suspects beside the internal speaker itself. The external-speaker jack's switch contact, the headphone socket's switch contact, the capacitor feeding the speaker's hot side C185 and the MOSFET Q73 on the receive speaker's ground side.

Maybe.

73

 

[Eldorado828]

Just recently ran into the c185 cap failure and only discovered it after tearing apart the radio checking switche, traces etc. Wouldn't have thought it but sure enough...

 

[dirtyjob]

thanks for your response, yes i tried doing that with the PA,, same problem. other than the ultra low rx volume the radio works as it should great modulation on transmit. Just ultra low volume, i have use it but need to crank the volume to hear people, their signals are normal.

 

[nomadradio]

i tried doing that with the PA,, same problem.

As in, very low volume for both receive AND PA?

That points to a factor that both share in common.

Any time the TA7222P fails this way, the DC voltage reading at pin 9 will usually be wrong. Should measure half the voltage found at pin 1. Pin 1 is the main power feeding the chip. If your radio's power supply is set at 14 Volts, pin 9 should read between 6 and 8 Volts DC. Turning the volume up and down should not cause it to fluctuate more than a Volt, tops.

And if you have a 'scope, probing pin 9 tends to rat out a bad chip at a glance.

73

 

[dirtyjob]

ok, now i have some good info to begin with, thank you I will report back.