Sony CF-480 (1976) - Capacitors replaced & internal Pictures

Discussion in 'Tech talk' started by Hyperscope, Oct 7, 2024.

  1. Hyperscope

    Hyperscope Well-Known Member

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    Sony CF-480 (1976 according to Radio Museum page). I would never have got this from e-bay if I had known a CF-1990 (CF-490 outside Japan) was soon to be available from cassette2go. Too many of these Mono Boxes lately :biggrin:

    A solid very well made "Mono" cassette recorder and radio, AM, FM and Shortwave.
    Has a single bright illuminating bulb on the radio dial near the VU meter. Runs on 8 D cells.

    EDIT November 2024: In side by comparisons with this CF-480 running on 8 alkaline D Energizer and the CF-1990 (CF-490 / CF-495) running on 4 alkaline D Energizer there was a difference in AM and Shortwave reception selectivity and sensitivity. The CF-480 was superior. Quite noticeable when DX'ing faint AM stations at night. The stations selected easily and were loud and clear on the CF-480. The CF-1990 was softer, a little off, stations did not "snap" in crisply. And when they were tuned in well they sounded fainter. There was a thin veil of fuzziness over the weak stations. (Radio calibration off? Or design difference?.)

    Also, in addition, the 12volt CF-480 is capable of going much louder. Speaker is driven better it seems. The 6v CF-1990 just sounds a bit weaker. Sliding the volume up it gets very loud, yes, but has a different speaker and less watts available. CF-1990 is for Bass response.

    Now I start to understand why the CF-480 (CF 1980 in Japan) was Sony's King Mono with at least 5 iterations or different versions released. Hmmm

    END EDIT ======================================

    Uses two belts in the Cassette plus one for the counter. The belts are from Turntableneedles.
    Square Belt, Small 10.0 Inch 1.2mm x 1.2mm
    Square Belt, Small 5.3 Inch 1.2mm x 1.2mm
    Square Belt, Orbicular 6.0 Inch <--- for counter belt 1mm x 1mm (smaller square)

    As it came from e-bay the AM radio worked briefly before fading away. FM was fine.
    Cassette turned but weak. No wonder. The old belts, 48 years and 7 months old, were dry and stretched. And the pulleys were filthy with rubber residue. It took about 25 cotton swabs and 70% alcohol to clean them fully. And many small 70% alcohol wipes pressed with a plastic "blade" into the V groove of the pulleys. Oiled all I could with 100% synthetic "liquid bearings". Radio faded away from aged electrolytic capacitors. This was solved by a general replacement with Nichicon FG and FW. (Yes I know it is not necessary to replace all with audio grade, just that, being a fool, I simplify by ordering all the same type capacitor.)

    Cassette mechanism old grease was a combination of grey grease, still soft and without evidence of hardening, plus some orange hard glue grease on the mechanical cassette buttons. And even that orange grease was soft and not really a problem. I did not have to loosen or dissolve any grease. Just a re-oil on some points to rejuvenate.

    The 3 idler tires were in extremely good condition. Smooth hard black rubber without powder residue or cracking. They wiped up great with 70% alcohol. Did not use Rubber Renue. Maybe should have?
    The pinch roller cleaned up superbly too. I would say this cassette mechanism had under 100 hours on it?
    Something low anyway. And that makes a big difference apparently.

    E-bay seller, when asked, said this radio came from a moving sale of an old guy, a collector, nearby, in Alamogordo Arizona just a month or two prior. Either it was in an air conditioned place for decades, or was hot and dry for decades, or acquired in the last couple of decades from another climate etc., who knows.

    Anyway, it sounds good. Nice bass. These radio cassette corders are, in my opinion, radio's, shortwave radios, that happen to have a cassette as well. To record off the radio. Stuff like the desperate dire worldwide situation... as events spiral out of control... and everything descends into flame :reelspin::reelspin: In other words still very relevant :biggrin:

    CF-480_00.jpg

    CF-480_001.jpg
    Brass inserts for the 6 long screws that hold the back cover in place.

    CF-480_01.jpg
    Ugh, one of these styles, have to remove cassette door and take out
    this single screw before you can pull out the chassis from the front
    "shell" housing. To remove cassette door one has to carefully pinch in
    the two side plastic clips on the moving door part. Tricky as they could
    snap off at any moment. Idiotic design. Why is that single screw needed?
    I assume it is to align the inner chassis with the front "shell"?
    It's all plastic so no about grounding.

    CF-480_02.jpg
    Belt path. uses a 10.0 inch main belt that is 1.2mm x 1.2mm.
    And the smaller secondary belt is 5.3 inches and 1.2mm x 1.2mm.
    From Turntableneedles.
    Square Belt, Small 10.0 Inch
    Square Belt, Small 5.3 Inch
    Square Belt, Orbicular 6.0 Inch <--- for counter belt 1mm x 1mm

    CF-480_03.jpg
    Took about 25 cotton swabs to clean the pulleys and motor brass of
    old rubber residue and dirt.

    CF-480_04.jpg
    Conveniently opens on plastic hinges for easy belt access and replacement!
    (Except for replacing the counter belt - that needs to full access which
    means removal of internal chassis from front shell. Easy. No screws.
    Just lift out carefully after removing slider knobs and tuning knob.

    CF-480_05.jpg
    All electrolytic capacitors replaced.

    CF-480_06.jpg
    Radio board has 5 electrolytic capacitors.

    CF-480_07.jpg
    EDIT: Electrolytic caps almost all replaced, this pic at
    this stage shows 1 left to do still.

    CF-480_08.jpg
    When chassis is removed don't overlook this little leaf switch!
    It is for the light. And in this case it was heavily tarnished / oxidized
    with filth. I just use 99% alcohol on Q-tip that is flattened.

    CF-480_09.jpg
    Motor has what appears to be a date code. 02766E. February 1976?
    Congruent with date of this radio of 1976 from Radio Museum.

    CF-480_10.jpg
    VU meter was stuck. Youtube videos explain to fix this common issue.

    CF-480_11.jpg
    Remove VU meter and carefully open up. It was lightly glued in this case.
    Not held with tape like the CF-490 (CF-1990 in Japan).

    CF-480_12.jpg
    Place tiny drop on nail polish remover on the green screw lock lacquer.
    This softens it. Then use jewelers screwdriver to slightly loosen the screw.
    Turn Counter Clockwise. Till needle moves fully again. Blow on the needle.
    Don't touch it. Too fragile and easy to bend or break. Once it moves freely
    put back together and re-install. Just like the youtube video taught me.

    CF-480_13.jpg
    Uses a 2.2uf 50v Bi-Polar capacitor on the tweeter.
    Great. I ordered 2 for the other radio cassette boxes
    (CF-1990 and Sanyo M-2448) and now I have to order a 3rd.
     
    Last edited: Nov 8, 2024
  2. euroflash

    euroflash Member

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    Nice work, Hyperscope! I appreciate the detailed description and helpful tips.
    As for grounding, I reckon it has to be grounded somewhere somehow to discharge electricity. But who knows what's with the boombox's design... I understand that poor grounding connection can cause problems with cassette decks.

    Once again, thanks!
     
  3. Jan de Lange

    Jan de Lange New Member

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    Nice! As you know I am struggling with the Fast Forward on this unit. Could you make a video with FF in operation so I can see why mine is not working? Also it may be that I need to pull off the flywheel to get access to the underlying mechanism, but this seems to be obstructed by a smaller white / copper wheel. Do you know how to remover the flywheel properly?
     
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  4. Hyperscope

    Hyperscope Well-Known Member

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    It will be a while before I open up this CF-480 again - waiting on 2.2uf tweeter capacitor. Will try to post video of FF and RW. But there is not much to see with this mechanism, seems obscured, not clear / obvious. The white movable pulley that blocks the flywheel, yes, I know what you mean. It is difficult to deal with.
     
  5. Cassette2go

    Cassette2go Well-Known Member

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    The white pulley does it move at all? It looks like a tensioner? Does it move when fast forward? Rewind or play is depressed? If it does move then in whatever position moves it away from The flywheel then you could possibly remove the flywheeler at that time.
     
  6. Hyperscope

    Hyperscope Well-Known Member

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    The white pulley can be squeezed out of the way, FF or Play, can't remember which, allows more movement, just enough to sneak the flywheel out. I will have to open it back up again to replace that 2.2uf 50v tweeter cap when it arrives so will try to remember to check. Other than that I have already "forgotten" all about this CF-480 and wish I never got it. CF-1990 is so much better looking and sounding.
     
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  7. Cassette2go

    Cassette2go Well-Known Member

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    Well I'm glad you got it. The 480 that is. So now I don't have to get one myself. You've gotten one and explained it to all to us. I have switched gears and gotten a Sanyo MR-G380 Sanyo MR-G380 front mono music search 05.jpg from over there. I'll update this later with the exact model number but it it is a one of their larger models. I think the largest and it has music search and it's a mono with two speakers.
     
    Last edited: Oct 15, 2024
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  8. Hyperscope

    Hyperscope Well-Known Member

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    Sanyo MR-G380 that's an interesting one... huh. Looks like the main speaker has some kind of central "thing" like the Coaxial speaker on the Sanyo M-2448? Plus a smaller tweeter so it could sound even better than the 2448.
     
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  9. Cassette2go

    Cassette2go Well-Known Member

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    When searching for this exact model, you will see that there are two different colored models. One is black trim and this one is silver trim and the silver trim comes with the speaker inlay if you will but the black trim does not but they don't differentiate with the model number so you have to look closely. Edit PS I paid for the shipping this morning so I should be getting it sometime. Middle next week.
     
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  10. Hyperscope

    Hyperscope Well-Known Member

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    I suspect the silver one was a later iteration with this change. Maybe an extra little upgrade while they were at it.
     
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  11. Hyperscope

    Hyperscope Well-Known Member

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    Update: The 2.2uf 50v tweeter capacitors arrived. Have some pictures but server error prevents placing them here (at any size). When forum accepts pictures again I will upload along with service manual captures of the top mixing board layout. (NOTE: picture of board back with the traces was adequate. Make sure to take before pictures in case a solder bridge is accidentally formed in the process of changing the capacitors.)

    I also recapped the little "mixing board" in the area of the volume and source sliders. 5 electrolytic capacitors: Two 100uf, Two 33uf and one 0.47uf. (The original cap voltages were low, 10v and a 6.3v etc., new ones are 25v and 50v. If this helps any future readers.)

    Sony_CF480_Tweeter_Cap_01.jpg

    Sony_CF480_Tweeter_Cap_02.jpg

    Sony_CF480_Tweeter_Cap_03.jpg

    Sony_CF480_Tweeter_Cap_04.jpg
    The circuit board is held with black plastic tabs holding it down.
    It is easy to remove the circuit board. Both sides have tabs holding it.

    Sony_CF480_Tweeter_Cap_05.jpg

    Sony_CF480_Tweeter_Cap_06.jpg
    Here is the back of the board to see the trace layout and check in case
    a solder bridge is accidentally formed.


    Sony_CF480_Tweeter_Cap_07.jpg
     
    Last edited: Nov 4, 2024

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