Galaxy 2527/RCI 2950 (non-dx) board can't vary power.

[PoDuck]

I found something that is causing me to scratch my head a bit, so I thought I would see if anyone here knows where I should look.

I have a galaxy 2527, which is the same board as the original 2950, and I am having a heck of a time figuring out what was done that is keeping me from having variable power.

I went over the board, and I have noticed that whoever was in this thing did a few stupid things, and screwed up a good radio. Someone totally destroyed the 54Mhz trap, which I will have to replace. I don't even know how they did what they did to it. They also turned the power up to 15+ volts, which destroyed a bunch of resistors, bulbs, and traces on the CPU board that I had to repair. They cut R249, which I replaced. They had the AM power turned up to around 20 watts, and have somehow made it so that the variable power doesn't work.

I can turn down maximum power just fine, but low power does nothing. In fact, no matter where I move the RF Power knob, it is full blast.

I'm hoping someone knows what would cause this problem. I guess it could be some bad component, and not the result of people tampering with things, but my instincts tell me that if there is a problem with the power, and someone messed with the power, that someone probably screwed up the power.

 

[nomadradio]

The front-panel control could be unplugged, or defective. The minimum-power trimpot will cause this fault if it goes bad.

But those are the three things to check that come to mind first.

73

 

[Onelasttime]

It is too bad they did not have standardized test's one has to take to determine which radio you can buy! LOL......It would also be nice if it was a felony to speak anything other than English on two-way radio within the borders of the USA.

 

[OldTech03]

First are all these still part of the circuit just basic make sure things especially C10 if were shorted it would disable the whole circuit. Also like Nomad said to make sure the RF Power control is in the circuit but if you can confirm everything in the diagram is part of the circuit and get measured positive results at different points then you go on from there.

 

[Low_Boy]

Probably not the same problem but I had a VR9000 with the same problem as you are having and there was a VR near the front of the radio right next to where the TX frequency was to be set. My radio had the same board as a galaxy 99. Any way there was that VR in the front of the radio that was not on the tune up specs or schematic that set the low power. RCI must have made a change. Possibly your radio has thet same VR? Blue and white VR between the two plugs.

 

[PoDuck]

The front-panel control could be unplugged, or defective. The minimum-power trimpot will cause this fault if it goes bad.

But those are the three things to check that come to mind first.

73

I didn't check for defective potentiometers. I just checked that they weren't removed from the circuit. I will have to do that.

First are all these still part of the circuit just basic make sure things especially C10 if were shorted it would disable the whole circuit. Also like Nomad said to make sure the RF Power control is in the circuit but if you can confirm everything in the diagram is part of the circuit and get measured positive results at different points then you go on from there.

View attachment 23181

D42 was there and tested fine, VR15 was there but not tested, and C10 was there and I didn't test it beyond making sure it wasn't shorted. I checked those before posting this. I haven't checked if the RF power pot works, but I did test that it is grounded. I didn't check VR16 or R59, so I will have to do that.

Probably not the same problem but I had a VR9000 with the same problem as you are having and there was a VR near the front of the radio right next to where the TX frequency was to be set. My radio had the same board as a galaxy 99. Any way there was that VR in the front of the radio that was not on the tune up specs or schematic that set the low power. RCI must have made a change. Possibly your radio has thet same VR? Blue and white VR between the two plugs.

No, it isn't the same problem. Thanks for the suggestion though.

I have been kind of out of commission for a few days after a surgery I thought wasn't going to be as painful as it was, or how out of it I would be, so I haven't been able to check any suggestions I hadn't tried yet, but I will probably be getting to it in the next couple days.

Thanks for the suggestions.

 

[Low_Boy]

I had a Stryker the other day that was the same way as the VR9000. They hid the VR for low power in the front of the radio.