Galaxy DX 929 - Possible Power Regulator Issue?

[67Malibu]

Hello everyone. A 929 came across the bench with a strange issue - No TX whatsoever, and RX only comes up when the Dimmer Control is turned all the way down. I was wondering if anyone had seen this before and maybe knew of the fix. Could it be a power issue? Maybe it is starved for enough current to properly run all systems simultaneously? I've searched for a voltages chart for this radio, but haven't had much luck. Any help/advice would be greatly appreciated.


67Malibu

 

[Eldorado828]

Hello everyone. A 929 came across the bench with a strange issue - No TX whatsoever, and RX only comes up when the Dimmer Control is turned all the way down. I was wondering if anyone had seen this before and maybe knew of the fix. Could it be a power issue? Maybe it is starved for enough current to properly run all systems simultaneously? I've searched for a voltages chart for this radio, but haven't had much luck. Any help/advice would be greatly appreciated.


67Malibu

Did you check the el ribbon connector and or unplug the ribbon connector all together? Sounds like part of it may be the el driver. I only mention because both the el driver and part of the mic input circuit being located relatively close to one another and you mention dimmer interferes.

 

[Handy Andy]

And if they put the wrong header on the wrong board.



Interconnection Diagram for a 919 - using same board - but it's the HEADERS, I want you to trace to and from the front panel to see if one header got swapped for another



These are not Keyed to go one way, so the header can get twisted around and installed backwards - check RF Gain board and EL dimmer board for header swapping or reversals.

 

[67Malibu]

Thanks everyone for the replies. I don't think it's a case of reversed cable plugs. The radio owner informs me the unit was working properly when removed from his vehicle, but it was when he later tried using it on his base station that the odd symptoms first surfaced. Any others thoughts on the possible cause?

 

[Dr. Frankenstein]

A few questions to maybe help get better answers from others on the form.

1. In which direction is the Dimmer control turned to have Receive: CW, or CCW?

2. Are the lights Dim when you have Receive?

3. What about the RF Gain ..... Does it lower the receive as you turn it CCW?

Let's get into the insides of the radio....................

4. With the Dimmer set:

a. To have Receive:
Key the Microphone to transmit:
1. What is the voltage at L41?
2. What is the voltage on the mirror board?
3. What is the voltage at pin-9 of the PLL 9 (IC3)?

b. To not have Receive:
Key the Microphone to transmit:
1. What is the voltage at L41?
2. What is the voltage on the mirror board?
3. What is the voltage at pin-9 of the PLL 9 (IC3)?

There should be a voltage to the answers to both "a & b" questions, if not there is a Short.

As far as the "no TX" problem, that could be a bad final, driver, or something else unrelated to the Receive problem.

 

[loosecannon]

sounds to me like the radio's owner tried to power it up at their house using a 12v 100mA wall wart.
LC