Superstar 3900 low light/power issue

[jellyhead]

Hi, I brought a 2nd hand 3900 (my second one) and plugged the frequency counter in the back. The lights on the front are really dim and it seems it has a power issue. I then pugged the FC into my st 3900 (which was working ok) and im now getting the same problem!

1) are the Superstar FC's compatible on all 3900 models?
2) Can the FC be repaired?
3) Can anyone advise what the issue could be and is this an easy fix?

Cheers

Jellyhead

[cb4ever104]

Hi.

1) I'm pretty sure the external counters are all the same. I think there's about 4 or 5 different brand names , but they look to be all the same.

2) There's a schematic for it , so I'd say yes , although I've never had to try and open one. I'm not at home , so I can't look at mine.

3) Maybe a zenor , or something that's gone ?

Sammy

[astradyne]

Hi.

1) I'm pretty sure the external counters are all the same. I think there's about 4 or 5 different brand names , but they look to be all the same.

2) There's a schematic for it , so I'd say yes , although I've never had to try and open one. I'm not at home , so I can't look at mine.

3) Maybe a zenor , or something that's gone ?

Sammy

Definitely an issue with the counter Sammy. It appears to have caused damage to his radio's.

Jellyhead. Did you own the counter beforehand? Or was it supplied with the second 3900? As Sammy said, they're basically a generic counter available under several different brand names. The only difference being the older model has a red display. Later models have green and blue displays. They're a plug and play unit and will fit all versions of the 3900's. You can also buy a wiring harness (I think Sammy sells them) which can be retrofitted into older radio's.

Anyhow, more investigation is needed. Check the counter thoroughly with a multimeter. Something is obviously wrong with it. If you report back your findings we'll be able to help further.

[astradyne]

Here are a few things which may assist you.

http://www.cbtricks.com/radios/galaxy/fc347/index.htm

[cb4ever104]

Also. Does the DIM button make the display even dimmer ?

[13EL121]

Check voltage regulator on the counter PCB.
And have a look here...

https://youtu.be/rkJjs9tIpew