I learned more about soldering and electronics in this 5 minute video than I have watching hours of other videos. Oh, and I feel confident enough to try this on the next dead radio I find. THANK YOU!
Thanks for the video. I've got a cobra 21 ltd that I picked up from a thrift store for $5. Opened it up and found the oscillating crystal laying inside (the legs rusted off). Replaced that and when it didn't power on, I found your video and took a closer look. I found the protection diode was broken apart. Now it works great.
How odd to read your comment. I too have a cobra 21 LTD with the oscillation crystal what I thought was burnt might be rusted as well, laying inside. I don’t have another Crystal but when I do I’m going to replace that and we’ll go from there
Thank you very much I have googled this problem for 3 days now now and get nothing but how to hook up your radio to some kids hooking his speaker wires up backwards you have saved me alot of run around I tank you very much and will be following any of your tricks and trips thumbs up...PLUS YOU SPEAK ENGLISH BIG PLUS thank you so much again..Charlie
Good video.Its exactly the same method of repair as what I do on ham & marine radio's. This is the most common repair job as everyone has mixed up the polarity sometime.
Would a Kenwood transceiver uhf be the same ended up with one off ebay kind of ended up overpaying for it didn't really want to radio but figured what the heck he said it was hooked up backwards and some magic smoke come out I looked at the circuitry schematic and I seen like 5 reverse polarity diodes in the schematic will these emits smoke when they blow are Wonder maybe a capacitor not sure
Gday Mate, I have just acquired General Electric SSB Model 3-5826A and no power on test ! May I ask if the diode on this model be about the same position as the one you described on this video ? I have managed to download the service manual with schematic diagrams but not too sure on the correct diode to replace Any advice would be greatly appreciated Regards Craig Queensland Australia
Wow, and I just bought a 5th radio... I've crossed the wires on all 4 with no cb shop in sight... Thanks a million I have a daugher in law who sauders for a living...
Got a gift of a high end CB . He tried to cook the radio by putting higher , and higher fuses in. Tracking foil with volt ohm meter and tinning the lands in involved diode replacement next after finger nail polish dries tks Fer your insight on reverse protection I might be a winner de kv4li
I have a Dwight D base CB, the meter signals are both to the right, It was my dads, he passed away and was gonna finally gonna hook it up and noticed the meters, Is this fixable.
Ok, found the problem. When I shorts the jumper lead going to the plug if the radio, it apparently melted the solder on my leads. Been chasing the lack of power problem all afternoon! Bad leads!! One of those things that make you question your sanity. 😂
I think i noticed a film over some parts. I thought somethings melted with the heat inside my car that had been sitting for awhile. I'll have to check that diode. Been awhile since i turned it on because i had no vehicle for many years. Thats about to change so i want to get the old radio working again. Thanks
Hi please can you help ? I have a cobra 40 plus I love but thear is no digital display but when I trigger Mike as red light comes on I don't think it's the power diode cause it makes scelch sounds , any idea I have the radio apart on my dresser thanksl
I bought a $5 charger with two antennas, I don't know anything about them. The radio seems to receive great but does not transmit, I tried my friends mics and it tends to be the same story. Where should I start?
I have a 29 LTD Classic. Bought from a guy that said it was new and never installed. He had it in garage for 2 years. However when I put power to it it doesn't do anything. I replaced the diode thinking it was that but no go. What else should I try?
Hello Mike, I have a question. I bought a Maxon MCB-10A Micro Mobile CB radio from eBay trying to save money because the very similar Midland 75-822 or Cobra 75 WX ST is so expensive. After arrivaval from eBay land I hooked it up to my truck and testing it, it would transmit very well and transmissions from 50' away I could hear.(the SWR was high)Driving down the road I could transmit and be heard very well but I very quickly lost my receiving ability. I could be heard but I could not hear. Like I said the SWR was a little bit high I didn't want to mess with the SWR and change it compared to the normal radio.What I need to know is what is the normal reason for a CB to not be able to receive a transmission? I did notice there were a couple of companies that had new old stock replacement parts of the MCB-20A additional power/antenna connector box. Could that go bad and allow a good transmit and bad receive? Like I mentioned earlier at close range I could hear but not at a distance. This is above my skill level at the moment for radio communication. I thank you for any assistance. Hey maybe a troubleshooting and causes video?
Good video and the usual suspect . If someone took out the diode and turned it on it wiolcwork but always have DC rectifier diode re-installed upon repair. 2# If someone shorts it without the diode installed the audio chip will be damaged next . AM only cb radios use 2-3 amp where sideband radios use 5-7 amps fuses most commonly .
I’ve got a nearly new midland cb model 13-884. Powers up but no transmit or receive. Not sure what my next step is. No squelch either. It’s connected to an antenna and a 12vdc power. I haven’t opened it up yet to start looking as I’m Not sure what to look for.
Depending on saturation level, immediately remove it from its casing, exposing the internal components as much as possible. Then put it in a bag and dump a little dried rice in with it. Don't be afraid to put some right on the components, just be sure to get all of it out of the nooks and crannies afterward. Leave it sealed in the bag for 24 hours, remove. Shake out excess rice. Put it back together and it should be fine.
Dear Mr Dad ... My name is Marcus Motta and I live in the state of São Paulo Brazil. I have a CB Radio Cobra 148 GTL serial number 83018940 (by Taiwan) - an old model from 1980/90. I spent a long time without operating the radio and now when I turn it on, I realize that it doesn't receive any signal at all on channels ... only QRM (noise) ... Some indication of what could be happening ??? ... some diode or electrolytic capacitor???...lamentably I do not have the wiring diagram. thanks for your attention ... Motta, Marcus
could have shown the 'prove it's shorted' way. either just break the diode apart and see if the radio powered back up, proves it's the diode, or take out diode using a diode tester and see if it's dead short.. never assume it's just the diode, could easily have burnt a track, and also it could have also taken out the audio IC, especially being wired the correct way with the diode already shorted..
only thing there is although the diode is shorted when wired backwards and is meant to blow the fuse,and also blow the fuse when wired the right way (diode still shorted) remember not everyone uses a fuse and cars and trucks run from batteries which have a lot more current so when a diode is shorted and power is applied correctly then the damage can occur to the audio IC, various tracks and in some radios other components..
to be fair i have never in over 30 years seen the finals damaged by the radio being wired backwards,but that said in the UK our radios may be built slightly different, but as the case a lot of the time people have no fuses, wire them backwards and keep trying to power the radio, wire them the right way with a blow diode and some times the current is not as much as you'd think and causes damage or way too much and just melts things.. maybe why Ham radios have two fuses in their power leads as you wire the radio backwards the negative is also fused in case.. but yes wiring a radio backwards for show is a daft thing to do, especially if he did blow the audio IC or something else, he'd look a mug then :)
bigpimp347 Wouldn't that be the fault of the fool that bypassed the fuse? I DO agree with your thoughts on Mr. Idiot ass not replacing the blown fuse, though. Look at the guy! Doe's he look competent to you? He looks as though he's sitting next to his front door, and the only furniture that he has is an old card table. Weird.... He only has one radio as well.
