Yes had the same problem on my IC-7000, no audio. Radio was only a few months old and sent it back for warranty repair. It still works fine to this day. That must have been about 10 years ago. Now I know just what they did. Thanks for sharing.
hi.Peter...What an exceptional video this was! As a non-RF engineer or electronic engineer, I am unable to fathom attempting such a task. Nonetheless, I thoroughly enjoyed it. It is evident that a great deal of patience is required for handling such delicate matters.
That was a nice repair, a bit of a pain removing the boards though. I've found in those tight spots, if you need to remove a transistor where the collector is soldered to the board as a heat sink, low melt solder makes removal of the component much easier. Of course, you have to wick up the low melt before installing the new transistor. Thanks for the Saturday morning video Peter.
Radio is not deaf, just dumb. Wow, Peter, that was a quick diagnosis by injecting a voltage to the amplifier. Your found the culprit by following the path. Cheers from Rusty in eastern TN
For piece of mind would it have not been better to change the transistor?? Few extra bucks you had the hard work done getting access to it, and the next question is how did it get that hot?? The 7000 is known for running hot but to desolder a component is serious heat, thanks for the video
@@ukrainehamradio R2624 is just the bias for the series pass transistor. If it went high or open then the transistor wouldn't pass any current so no heat. I suspect the transistor isn't rated high enough for the job.
In general, we can say that these radios are known for getting extremely hot, especially if the output power is tuned up additional. Here it was a mix of different bad things.
@@TRXLab and company, I have a couple of these and they are great radios. Even with an extension speaker, the AF stage is very very poor. Perhaps it was used mobile, and forced into clipping, causing the heat on top of what is already warm working conditions.
Some time ago I repaired an IC-7000 with similiar issue, no audio. In my case the problem was in front panel; infact the connector on front panel gives to CPU the signal if an headset is on or not; if there is an headset, CPU turn off internal speaker !!! In my case CPU turn off always internal speaker (and external speaker on the rear) because the connector on front panel was wrong, defected !!! Thanks Peter, great video, best 73s de IW0HEX Pasquale
Had same failure,but,also plugged a headphone into the front panel initially to test ,and had audio there.then it was determined that the headphone plug was not closing the contact .sprayed some contact cleaner on the tip of the phone plug. Insert and wiggled it thus cleaning the internal contact. Hate to say it but Peter missed the headphone jack.
Yeah, this type of radio is doing a lot of funny things. Additionally, those radios are getting old now so you always have a mix of aging and other issues...Take care 73
Hi Peter I have been following your channel with great interest for a long time. Thank you for another exciting repair video. It's always great to see how you solve these puzzle games! But I have another question: Why did the transistor get so hot in the first place? And did it stay cold/warm after the reflow?
Hi Peter i have been following you for many years your incite and approach in trouble shooting is top notch i have a question that you may want to share with others --- where is it that you get the detailed service manuals I have many but nothing like what is shown here ... keith in canada
It seems odd that a transistor can get hot enough to melt nearby solder - unless it's malfunctioning or there is some other issue. Do these thing really run that hot?
In general, we can say that these radios are known for getting extremely hot (much too hot as design error), especially if the output power is tuned up additional. Here it was a mix of different bad things. 73's
Oh boy, that is a more complex story as one think. These transistors are special FBET/LSBT process chips. This is a special technic, basically develop for TV horizontal amplifiers. Here in this case the type is involved in the low pass filtering to keep the DC RF clean. This type is robust against transients and induction switching issues. And to be clear, this is not the complete really complex story..., but just an idea to understand..
I don't like the idea of a transistor running so hot that it melts the solder. That's not right. I did wonder if it might be a bit small for the current it has to pass, especially at high volume levels but it's rated to 2 amps (assuming decent heat transfer coefficient) and I don't see the audio chip pulling that much current for long periods so it makes me wonder what caused this.
In general, we can say that these radios are known for getting extremely hot (much too hot as design error), especially if the output power is tuned up additional. Here it was a mix of different bad things. 73's
