Vintage SONY Digital Clock Radio ICF-C12W no audio

[Agent24]

Obviously *something* isn't fine, or we wouldn't be here...

[UserXP]

Yeah... he even suggested that the old capacitors may have been some kind of special series for radio/audio circuits and that the new ones could be of different internal resistance, affecting the signal strength. My other unit has Elna, Lelon and Rubycon caps inside, all rated at 85°C... I am still waiting to see what will come out of his diagnostics, at least he has all the necessary equipment at his disposal. That "something" bad is really a gold nugget I'm curious to find.

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[CapLeaker]

He should have found it by now, if he got all the RF equipment he needs.

[stj]

the guy is full of shit,
they didnt have high-spec electrolytics back then, and they arent used in the RF path anyway.
he just doesnt know what he's doing, he's probably used to fixing audio gear and not rf.

[Agent24]

Yeah... he even suggested that the old capacitors may have been some kind of special series for radio/audio circuits and that the new ones could be of different internal resistance, affecting the signal strength.

Yeahhh I can't say there's much to that idea... maybe he means "audio grade" capacitors used in high-end Hi-Fi because they "sound better"...
But like stj says, that's not really relevant here... not that I know of... because most of that is placebo effect anyway... for audiophools...

[CapLeaker]

RF is different from AF. That’s why I said that if the guy has the proper RF equipment, he should have found the problem already. Even if the guy doesn’t have much of a clue where the problem is, all he needs to do is a full alignment from A to Z. The problem will pop up.

[UserXP]

I spoke with him today, he said he had started doing the alignment as he had other repairs, so hopefully something will pop up.
I am prepared for any outcome. The radio is older than him, I'll tell you that much - but, it doesn't have to mean anything. 🙂

[stj]

he should watch some shango video's
https://www.youtube.com/user/shango066/videos

[UserXP]

Hi, all.
Sorry for the long delay, but there were some things that needed to be done. In the meantime, the service guy has found the fault with the radio, but claims he cannot find spares due to age (which I believe is so), nor does he have a donor device with the same parts to take from, again, due to the age of the electronics at hand.
However, he removed these three suspected components and sent me the images. These are, I believe, the FM transformers and something you had also suspected to be at fault.

Could you take a look at the images and help me find equivalent replacements? Does the colour of the trimmer denote a specific value? There are some numbers on the side, but they may be proprietary. On some of them it says "Mitsumi". I found some yellow parts identical to the one in the images, so does it mean they would, for example, work as a replacement for the yellow one? Does the colour actually denote the same value for all brands?
Please advise and thanks.

[CapLeaker]

Which ones are these or what did he take out? T1, T3 and T4 that I was talking about earlier? T1 is the IF transformer and T3 & 4 is the FM discriminator. Now which one is it? Can’t be all 3 of them, because the you could hear stations on FM.
Makes me ask if he does know this thing works? Again, if he has all the gear, he can pinpoint the exact faulty transformer.
Just waiting for stj to flip on that tech. lol.

[R_J]

My condolences to the radio.

[UserXP]

Yes, those three. The fault seems to be at T3 and T4. I saw the video he showed me, wiggling or pressing their pots/leads impacts the volume to increase as a certain angle is hit while wiggling or pressing. Maybe something got detached inside them, I don't know what the device had suffered at previous owner's.

T1 is the darkish red looking one, close to Q1
T3 is the yellow one
T4 is the blue one (these two are next to each other and close to IC01).

[Agent24]

Maybe you can get new ones like these
https://www.aliexpress.com/item/1005004483837060.html

I guess the wire could have broken inside due to old age/corrosion? It's very thin.

[CapLeaker]

Yes, those three. The fault seems to be at T3 and T4. I saw the video he showed me, wiggling or pressing their pots/leads impacts the volume to increase as a certain angle is hit while wiggling or pressing. Maybe something got detached inside them, I don't know what the device had suffered at previous owner's.

T1 is the darkish red looking one, close to Q1
T3 is the yellow one
T4 is the blue one (these two are next to each other and close to IC01).

Yes, these things wires inside can break off. Some folks take them apart and fix em too. As for unobtainable replacements: I do have those problems too. What I end up doing is going through other radio gear roughly the same age. One time I needed a slug for an old 1975 radio. The one I had broke off inside. Anyway, I did find the exact same thing I needed in a Motorola Mitrec VHF receiver. Lesson one, is to find THE culprit, don’t change a whole whack, because of lack of parts. Lesson two is: There are parts around in different radios, just hard to find. Usually these parts should be roughly at the same place if you look at the schematic. Tricky part is to find a radio that has that exact part. Either you find a parts radio or start skimming through schematics.