Car radio failure? (very strange)

Hi everyone,

since a few days ago I cannot listen to any of the FM stations. Here is what I could notice:

-MW & LW are OK

- FM sometimes works, but not for a long time (10 sec - few minutes)

- just before loosing an FM station, there is a time period of about 10 sec during which 'input level indicator' slowly arises towards the maximum and in the same time the station fades out - afterwards, there is only a silence

- after the station fades out: if I use a preset FM station, there is a 'full signal' indicator on the LCD, but if I try 'search', searching starts and it searches for the infinite time (going all around through all FM scale)

- if I am listening to a MW or a LW for a certain time period: then FM is OK, but only for a certain time period

- longer the time period of listening to a MW or a LW station is, longer I can use FM mode (no joke :-) ) before it fades out as described before

I have checked the antenna and other junctions. Does anyone know where could the problem be? Could it be a capacitor (the fading pattern makes me think something is slowly charging, something like an RC node). Or maybe a PLL module? Just guessing.

ps Sorry about my English

Thank you,

You'll have to post the brand and model number of the radio before anyone can help you.

Sorry, I've completely forgotten about the brand. It is a car cass radio supplied with Opel Vectra 1992. There are three notes on the front panel: 'Opel', 'Philips' & '684'. Unfortunately, I am not in a position to check the labels on the inside right at the moment. Since I am not at home, I cannot check the manual for the exact data but I shall try to reach the information as soon as possible.

Thanks for answering me,

Best regards,

If you have a bench power supply which can put out 12V or 13.8V then it will make troubleshooting a lot easier than trying to do it in the car.

The fault could be of a thermal nature, so heating parts of the circuitry with a heat gun or hair dryer until the fault starts, then cooling individual components with freeze spray should help you find the bad component.

Your English is perfectly understandable by the way, no need to apologise at all. Bear in mind that most of us native English speakers cannot be bothered to learn a second language, so I admire anyone who can master English to the degree you have.

Dave

I was already thinking of using an accumulator charger to make some testings.

Thank you, I shall try that.

Thank you, those (or should I say 'these'?) were very kind words.

Well, I was learning English since 3rd grade (basic school) till end of the high school (not extra classes, only as one of the compulsory subjects) and I was always lucky to have an excellent teacher. Later, we've had some techinical English classes at the university - with American teachers. Bonus is that we are watching movies with subtitles (I am from Croatia) so I hear English practically every day. +, I've had a lot of conversations with Hungarians, Russians, Australians, Belgians & Germans. That is why I am not sure if some of my sentences sound funny to the native English speaker, because each of the former mentioned have their own 'English grammar' :-)) For an example, in Hungary you can hear: 'I have to toilet' instead of 'I have to go to the toilet'. That is because of the nature of their language applied to the English language.

And, of course, I occasionally use small Webster's English to English dictionary to find out the spelling when I am not sure :-))

BTW I must say, the education in our region (former Yugoslavia) was very good, it was for free (as was the medical care) but very good, I would say outstanding, until the war. Nowadays, I am not sure, in fact I can say the education is not so good as it was. Furthermore, There was a lot off different languages that one could easily learn because we were all mixed, from the six former Republics. So, everyone older than 20-25 can understand Croatian, Slovenian, Macedonian, Serbian, Bosnian, not to mention the dialects. Even Russian, Slovakian, Polish are not too hard to understand if you would have lived here. I have always been interested in learning languages so I have even learnt some Hungarian during my 1 year working period accross the border (and believe me, Hungarian is not so easy to learn :-) ).

OK, this was rather offtopic, but you (or someone else) may find it interesting.

Thank you again for answering me,

Best regards,

I simply speak the truth as I see it. Some native English speakers, not necessarily a majority, seem to assume everyone should speak English, and are stupid if they get it wrong. What is ironic is that many people who speak English as a second language often do so better than some native speakers! They're usually a lot more polite as well IMO.

I do indeed find it interesting. I am fascinated by Eastern Europe and the Balkan countries. I intend to take a driving holiday one day and tour all of eastern Europe and the Balkans, perhaps even Ukraine, Belarus, and the Baltic countries.

I actually had a holiday in Croatia when it was still part of Yugoslavia and under communist rule. It was a real experience for a 15 year old and no-one else I knew had been to an Eastern European country back then.

We stayed at Porec on the Istrian peninsula, and had an interesting day trip to Trieste, which meant we crossed through Slovenia and crossed the 'Iron Curtain' by road into Italy. Exciting stuff for a kid! I have to say though that Porec was disappointing and I believe it to be too heavily geared towards tourism to give a taste of the real Croatia. If it had been my choice, I'd have preferred to have gone inland and seen the real Croatia, I'm not into resorts and much prefer seeing what countries are really about. The scenery on the journey from Pula airport to Porec was very nice though.

I know what you mean about Hungarian. It's distantly related to Finnish which is also rated as one of the most difficult languages to master, at least for English speakers. The pronunciation alone is extremely difficult for Western Europeans. Having said that, I understand English is difficult for people used to certain languages.

No problem, it's nice to talk to you.

Dave

You didn't cross the Iron Curtain', believe me :-)) The truth is, former Yugoslavia WAS a communist country, but our system was FAR FAR away from what people have in mind when they say 'communist country'. As you may know, we were one of the 'Independent' (I don't know what term is used for those countries that were out of Eastern/Western block). We've belonged neither to the eastern nor to the western associations. In fact, I would say, both of us were all the time on the same side of the Iron Curtain :-))

As you have said, Istra is nice (BTW, Pula is my born place, although I am from NW of the country) but you should see the other parts also, never is too late.

That may be true, I was reading about Finnish beeing related to Hungarian (and some Siberian languages also), they both are part of the Ugric-Finnish (I am not sure if I've written correctly) group of the languages.

It is extremely difficult for most of the Croatians also. But not for the ones who live on the NW (yes, that's me :-) ) because dialects used around here have very complex pronunciation impossible to write using Croatian alphabet.

And to be ontopic again :-)) I can now listen to the FM for about an hour before station fades out. And it seems every day FM works for a slightly longer period, really weird.

Hello Chupo. Perhaps with the colder weather, the faulty component is taking longer to heat up? A suggestion - if your radio is mounted in a wall cabinet, take it out and see if it performs better with air circulating around and through the vent holes in the back. If that is not the case, remove the chssis from the cabinet and see if that helps. Another thought - is it possible that the FM stations you listen to have lower ouput at later times of the day? Perhaps you could borrow another FM radio to try when yours fades out. I have heard that many people in your part of the world use tube (valve) powered audio equipment. If your radio is of this type, a new tube in the FM detector section could be an easy fix.

John K

Sorry, I see that it is a car radio, transistor of course. Unless your car is a Lada. Sorry, that's a joke... :-)

It might be so, although I havent't noticed any difference when driving during the sunny afternoon (20 deg C) and after the midnight (5-6 deg C). And I haven't done any investigations yet. In fact I am going to insert an another radio (I thing they both have the same interface) since I have some more important problems to solve at the moment :-)

LOL :-)))) No, I still don't have walls inside my _car_. Maybe I should install the IRON wall :-)))) NHF :-)

It isn't.

Another LOL :-)) Are you assuming that was the only FM receiver I've had? Anyway, I have tried to use an FM transmitter and haven't noticed any difference.

ROTFL!! :-)) You are right, but these are mostly some audio freaks or guitar players who like 3rd & 5th harmonics beeing distorted :-)) OK, I have a tube radio from the year of 1956. but it is only an old memory.

Thanks for the help,

Best regards,

Or maybe Kamaz (KAMA3) :-))))))))))))))))

BTW Lada Niva - one of a few cars that you can wash from the inside _in the same way_ as from the outside :-)) That's NOT a joke :-))))