|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
22nd Feb 2020, 12:22 pm | #1 |
Diode
Join Date: Feb 2020
Location: London, UK.
Posts: 8
|
Sony ICF-SW7600 FM problem
Hi folks
I have one of this Sony radio which is not good on FM band. When i search for any station its just skip. But it is perfect on AM. Anyone had similar problem. Thanks |
22nd Feb 2020, 1:33 pm | #2 |
Heptode
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 675
|
Re: Sony icf-sw7600 fm problem
The 7600 has several generations/versions.
Which one is your radio? Best to post a picture! Regards, Peter |
22nd Feb 2020, 5:36 pm | #3 |
Diode
Join Date: Feb 2020
Location: London, UK.
Posts: 8
|
Re: Sony ICF-SW7600 FM problem
Hi. Its just a ICF-SW7600 which is the first product back to 80s. I will upload some pictures and also I took it apart and there is one picture of the main board.
|
23rd Feb 2020, 2:13 pm | #4 |
Heptode
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 675
|
Re: Sony ICF-SW7600 FM problem
It looks like the 7600G, at least the "matching" service manual has that title.
(Mine is called a 7600D, it is earlier than yours, and it looks like the ICF-2002.) Here is the service manual for the 7600G: https://www.manualslib.com/manual/59...f-Sw7600g.html Based on the schematics, pg. 13 in the manual, you need to follow the FM signal path and see where does the signal "disappear". Regards, Peter |
24th Feb 2020, 1:31 pm | #5 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
|
Re: Sony ICF-SW7600 FM problem
Hi
Along with other Sony radios of this era they suffer from failure of the Ali can capacitors . They leak their electrolyte which as well as affecting their capacitance etc can spread onto the PC tracks causing corrosion and electrical leakage where it's not wanted ! It can also get into coils causing them to go o/c . If you look carefully at the bases of the caps your might see some leakage or corrosion of the solder lugs on the caps. Also there might be a smell ,all tale tale signs of cap failure . Check under the buttons on the PC for signs of leakage or liquid spill Can be cleaned off with IPA Cheers Pete |
28th Feb 2020, 2:17 pm | #6 |
Diode
Join Date: Feb 2020
Location: London, UK.
Posts: 8
|
Re: Sony ICF-SW7600 FM problem
Hi, please look at the attached photo. What is that yellow stuff around the transistor? Is it factory default?
|
29th Feb 2020, 6:14 pm | #7 |
Pentode
Join Date: Dec 2015
Location: Abingdon on Thames, Oxon, UK.
Posts: 116
|
Re: Sony ICF-SW7600 FM problem
I had a problem with FM on my 7600D, turned out the wire to the telescopic aerial had come off.
Ken |
29th Feb 2020, 9:42 pm | #8 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
|
Re: Sony ICF-SW7600 FM problem
That gunk is a glue that Sony used. It can cause problems in some circuits as it sometimes becomes conductive with age!
|
5th Mar 2020, 10:57 am | #9 |
Diode
Join Date: Feb 2020
Location: London, UK.
Posts: 8
|
Re: Sony ICF-SW7600 FM problem
How to remove it and is it safe to clean it ?
|
5th Mar 2020, 10:48 pm | #10 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
|
Re: Sony ICF-SW7600 FM problem
Use a wooden toothpick and some IPA
Be careful around coils and transformers as it's easy to damage the very thin coils I don't think this is your problem though, far more likely the caps need changing. |