Channel Display

[jwPotts]

I have a Cobra 29 LTD Classic, with the LCD channel display only partially lite. I have the repair manual but it does not mention anything about the display. Can anyone provide any suggestions to trouble shoot or replace, such as just the LCD or the entire board?

[Rick]

9 times out of 10 its a faulty LED display, so the easy way is to just replace it.

[jwPotts]

9 times out of 10 its a faulty LED display, so the easy way is to just replace it.

Thanks Rick, I did find a reference here[/url]http://www.radiomods.co.nz/forum/viewto ... hlight=can you help?

[nomadradio]

The digits in that radio are an LED display, as in Light Emitting Diode.

Both digits are inside one chunk of plastic with sixteen pins, one row of eight on the top edge, eight on the bottom.

Desoldering it from the pc board is best done with a desoldering iron. One with a heated, hollow tip is available from RatShack as stock #64-2060 for ten or twelve bucks, pretty sure.

Best thing about this tool is that you squeeze the rubber bulb, apply the tip to the soldered pin and release the bulb as the tip melts the solder on the pin. The vacuum from the released bulb sucks the solder off the foil trace fairly well.

This minimizes how long you expose the foil on the digit's pc board to heat. Hold it on there too long and the heat will lift the foil from the board.

If you don't have experience with unsoldering and replacing components on a printed circuit board, maybe your Cobra's channel display is not a good "first-time" project.

Always handed a junk radio (or three) to a trainee, so they could see just how much abuse it takes to damage pc-board foil traces. No substitute for screwing up one or two of them, to get a feel for how NOT to damage the copper foils.

As for a source of the replacement display, Ebay has a few 'stores' who will sell you just one.

73

[jwPotts]

Thanks, nomadradio...for the walk through and information. I've got a vacuum type de-solder pen, and a couple of old pc boards to practice on, as you are correct I have as yet to work on a pc solder connection. The ratshack would be easier to work with, and the price is right. My hobby is restoring old tube amps, this is my first experience with solid state. RadioMods is a great forum and everyone helpful. thanks again.......

[ramblingman]

hello,i have fixed those by just reheating the solder joints.but like they say most times you have to completly replace it..if you dont have a new one,try to find a junk radio,that they work in,and use it.

[jwPotts]

hello,i have fixed those by just reheating the solder joints.but like they say most times you have to completly replace it..if you dont have a new one,try to find a junk radio,that they work in,and use it.

Reheating would definitely be worth a try....I located a 29 chassis that was destroyed by someone trying to mod that could not solder. Bought the entire chassis with good LED for 10 buck$. Thanks for the info.......ramblingman