I have to thank you again Peter, Because of your #118 I was able to work on my TS450s following you leadership and repair the same problem although my problem was the capacitor #104 had failed and it burnt off the trace between the + terminal on that capacitor and the output terminal #4 of the amp. Thanks again for all the help. Both radios work fine.

I appreciate you taking the time to clearly explain all of your diagnostic steps, and the logic used!

I saw that burned inductor in the first part of the video at about 1:41 minutes. Of course had I been working on it myself I probably wouldn't have seen it. That's usually the way it works, lol! Great troubleshooting! Enjoy your videos!

Trouble shooting is an art. Nicely done sir. I'm a nubee at all of this and really enjoy all of the time and effort you put into your videos. Big thumbs up, and Thank you for Sharing! Joel

Great diagnostic process as always. I'm glad you did not see the open coil early on, it would have spoiled the fun. I appreciate that you take the time to show the schematic.

I really do appreciate this professional lesson...Thank you master.

Another nice repair and very entertaining. Thanks for sharing the repair with us. Robert.

Another great video Peter...Superb fault finding.Great radio the 850 should go on for a little while longer.

Love the videos, the test tone is VERY LOUD at our end. keep up the great work :)

Another great video Peter. Congratulations!!!

Peter Great video Good to learn something new every day Thank You

Nice job as usual Peter. Good point to point fault tracing.

excellent video trx I've learnt a lot from this video hope you have a good Xmas

Thank you Peter for this one, You have given me the imfo to start on my own pair of 450 SAT radios that have the same problem. I have never plugged in any external speakers into them but they have many many hours of receive time on them almost no transmit time , again thank you very much for the lessen . I will let you know how i made out.

Great video & nice troubleshooting as always my friend. Kind regards John

Hi Peter. I spotted that burnt inductor near the start of the video. Easy fix thank God. George

Im with you. The scope does not lie. Many things are seen with the scope that the tracer wont pickup. Thank you for the wonderful video. You are the best radio tech on youtube.-+

Excellent job of trouble shooting, following along I was suspecting the electrolytic. And got a surprise that it was the inductor..hihi Great job Peter. Lloyd - W9NLA

I had no audio on my old Kenwood TS-430S and found the speaker was not properly connected. I never fixed it because I always used headphones or an external speaker. I also noticed that the 1/4 inch jack for headphones on the front panel would hang and not let the audio to the external speaker. I'd have to plug/unplug to get it to switch. I prefer headphones when operating my radio, 'cause the wife don't want to hear my radio since it is in the living room. I've got to relocate to the bedroom when we get it cleaned out. Cheers & 73 from W Rusty Lane K9POW in eastern Tennessee

How timely and wonderful Peter! Great video and you must be reading my mind. I wish I had a TS850 to follow along with, but instead, I have a TS450 with weak audio, but the line level out to an external speaker is still okay. I should probably part it out. I do have someone willing and begging to pay me as much as I paid for the radio, just for the auto-tuner, which works fabulously well. I do use the old audio tracers with the speakers or sometimes I just pop trace. That is really just a quick and dirty shortcut, but it works. When the fault is that close to the speaker, it makes it a lot harder, but an electrolytic capacitor and a coil on a board that is that smokey and cooked looking, what are the odds? What color code does all black and grey represent? Oh toasted. Yes indeed! I have other words, I tend to use, but not on KZfaq comments. Personally I don't like seeing electrolytic caps adjacent to Pentawatt audioamp ICs, power resistor and other things that get hot, but what can you do? We did not design it, we just fix them. A 30 cent inductor. Not bad, oh and $50 in labor. Happy Christmas, Peter. 73s KI7AQJ

very good step by step testing thankyou for video your the best ! Peter

Nice one Peter great fault finding procedure.......................................Berni

great video peter i have a kenwood 870s that down on receive i replaced lighting arrests and still the same i was hoping you were fixing a 870 lol

Nice work.

Thanks Peter, nice repair. 73s Pasquale IW0HEX

Another job well done !!

Really interesting, i learn one step up...Thank you very much.

Great video! I know many years have passed but I followed along with my TS-850 which had audio out but very weak. Turns out also my inductor was toasted (although it still measured 750 uH on the tester) but I believe the culprit is the electrolytic cap near it (C187) which decouples the output of the amplifier. My guess is that mine was shorted so the inductor (and speaker because there is no decoupling at the input of the Kenwood speaker) had the full DC voltage + the audio voltage on them and the inductor gave up.

Well done, thanks again Peter ! ! '73 Bob

Danke Peter, wieder echt klasse. 55 73 bis bald.

Here's wishing you a Merry Christmas and a Happy and Prosperous New Year. Don't get too drunk on the strong German lager though! LOL!! :O (From Wayne and Nina, from Ipswich, Suffolk).

hi peter,in the minute 2:15 of the video we can see clearly the toasted inductance.Anyway another great video,thank you for learn us

I like the way you lol when you find the problem

Good for your video i have the same problem with my radio

Cool stuff

What about replacing the output electrolytic in case it has been stressed by a short?

Very nice troubleshooting Peter. I also think he may have plugged in a bad speaker. Wonder if he has an amplified speaker that failed and put voltage back into the rig. It is hard to believe that there is enough current in the system to cook that 1uH choke. And leads me to think that voltage entered the external port. Keep up the great job my friend, 73 Buddy

Good morning, colleague, would you have or could I get the eprom of the Control Unit of the coupler ICOM 746 pro?, Because here in Brazil I can not find

Very good Peter ... I think: in market have a external speaker with amplifier inside .. maybe this is a reason ... return of voltage in speaker jack ... All the best

I Spotted that Burnt Inductor @2:04😉☺😁...I did watch the video to the end too see how long it would take you to spot it.....Just show's how a good eye or in my case a cheap pair of £1.99 Spectacles come in Handy.

Looking at the circuit, I wonder if C187 is leaking some DC which would heat L37 if the speaker output line became shorted or if it was used to drive a low impedance speaker for a long time...Something cooked L37 badly...!

Great work Peter. Nice way to trouble shoot that problem.

Any way to change that coil without removing the circuit board?

may i download the manual for ts850s

my 735 had no audio remember? Turns out the previous owner tried to remove the vco box cover that is soldered and dropped a blob of solder on the board....after replacing capacitors and tapping on the board, I finally found it. Radio is working. So it could be any possibility sometimes.

Thanks again! What is the purpose of that coil anyway?

A shorted speaker wire is what killed the audio in my Stryker 955. 1 tiny strand of positive got soldered to negative on a jack repair and I did not see it. It took out the audio amp, roasted and cracked open a trenchfet in the PCB on the ground side of the speaker circuit. They dont make either part so had to cross reference them and still waiting on the trenchfet to arrive. 21 days to get that little guy.

Da haste fast alle Messgeräte von Rohde & Schwarz und kommst dann mit einem Rigol Oszilloskop an. =) Du machst super Videos, ich schaue sie mir gerne an, mach weiter so! Vy 73 de DL7LL

I doubt if the amplifier would have enough drive current to fry that inductor. Maybe the series cap from the amp to the inductor went intermittently short? Most likely someone has applied power to the speaker jack.

good job good morning

I've seen some pretty bad solder joints (or screw terminals) inside the plug for an external speaker. My bet is that the short is inside the plug.

Hello Peter, Could that happen if the old man used a 2 or 3 ohm speaker pluged in for a long time.That could account for the board heat damage.

I notice there is a Phone jack in the front of the radio. Might he have used headphones and caused an issue from there? I know some radios use 1/4" jacks for CW keys. Might he have plugged a CW key in the jack in the front? Just a few ideas. Thanks for another great detective story! '73, Mike / KD2EAT

Great Video as allways Peter, how about fixing a young man's radio for a change. Just a thought dear sir

Well done Peter. On the bottom of the PCB there appeared to be a mod of some sort with a long wire, a couple of diodes and a resistor tack soldered onto the board; the solder looked a little ugly, may have been just a video artifact. May have been a factory kludge; did it look ok to you in real life? 73 - Dino KL0S

Doesn't it seem that the old man has a lot of problems with his equipment? Do you think it might be misuse of the equipment on the other hand it does keep you busy and us entertained. Thanks

Hi Peter. Can you give me the speaker jack number what ever you used. I cant find it Thanks

I have a similar problem .. when I turn on the radio do not hear the sound, after a few seconds (10 or 20) it starts to work. What could be my problem?

What is the dark spot on the board 14:30

CAN USING A 4 OHM speaker have caused things to heat up

change C187 (470 mikroF / 10V) to 470 mikroF / 16 volt. This capacitor becomes leaky because of voltage stress, and starts to conduct. In many times this capacitor starts leaking physically. This is the cure, a capacitor rated to minimum 16 volts DC. 73 :)

i saw that burnt choke in 2mins ,, its all gone black..jeff

maybe the owner had a long speaker line and rf got in?

lol he would have had to have that thing on a dead short and at max level to burn that thing up.... i know some power supplies use a head phone jack if he plunged some thing like that in that would smoke that in short order... sucks when things just inexplicably burn up... my kenwood TS-2000 just stopped transmitting out of nowhere. i was using it to talk to a friend 20 miles away on 15 meters after we where done we cleared the freq and 2 days later I powered it up and it would not transmit at all... "it was working on the last shift!!"

wow 158 likes and 0 dislikes a++++ channel

Burn marks on the case at two separate spots…

Yeah, it's pretty obvious he shorted an external speaker connection.

I need some one who knows about a Kenwood receiver/tuner

I bet someone accidentally plugged in a walwart PS and cooked it.

Super: i have an Kenwood TS450S and no Audio :) Have open the radio after watch this vid, and found the PA, same condition Pin5 13.5V Pin1 6.5V and Pin4 has full Audio - seen on Oszi and via test.Speaker. Found desolate Capacitor and have remove em from topside .. but after replace this one : no Audio will be come out, only direct on PA 4-Pin i have the signal. I think now, all capcitors in the line i must renew.. it's a bit dificult to remove all the neighbor -capacitors on the board.. the little black cube is an LC-Filter : there are here unknow, this type would be serch to replace this ones too. Have any one a Link to the Type of black LC-Filterbox behind the PA IC ? (never seen this formfactor befor) www.flexxvision.de/PublicImg/ken1.jpg www.flexxvision.de/PublicImg/ken2.jpg Thanks for nice Video , looking forward now :)

Don't viggle the plug.

why say 5 words when you can use 200,painfull to watch with all the uneeded waffle!,have you verbal dioreha?.