New Member: 91 GL1500 Tape Jammed

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Welcome from the state of Pennsylvania!

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A10Thunderbolt wrote:

Hi there, after owning 3 Gws over the years 1980-2008, I finally had a problem I'm puzzled about. I have a '91 GL1500SE and theres a tape jammed in the player. It was running OK but when I switched tapes, the L-R arrows for SEARCH went nuts and they BOTH come on at the same time now (pointing at each other and FLASHING)



I have the service manual for the bike but there's no advice in there about the sound system.



I suppose I should probably post this to some TECH part of the Forum but just got here and it said: FIRST Post to New Member Forum, so here I am



Alan

Click to expand...

I used to repair about 10 cassette decks a day when I was a warranty bench repair technician (way back).

What happens is as the belts age (starting immediately) they stretch before they crack and break. As this happens, either the belt or the clutch pads in the hubs get weaker and weaker. Eventually what happens is the clutch on the takeup hub can't pull like it should and the capstan shaft that meters the tape through at a constant rate grabs the slack side of the tape and wraps it around on itself.

Once that happens, the shaft (which has strong torque) keeps pulling tape from both the feed side and the takeup side until the it gets so much tape on the shaft that it fills the space in the cassette made for it and it stalls by slipping on the drive belt or the motor itself stalls. About 1/4" diameter of tape on the shaft accumulates, like a small roll of electrical tape.

Once this fills, the capstan shaft cannot slide out the small hole made for it in the cassette. You are forced to pry the cassette, tape wrap and all off of the capstan shaft or cut the cassette housing away to get the tape out. Of course you will have mangled the tape in the process. Most call this 'eating' the tape (left over from the 8 track days).

If you are lucky, the capstan shaft won't let go of the flywheel as you pry the tape off of it as it is lock-tited to the flywheel, and you won't have damaged your motor when it stalled. Prying can be difficult because if there is enough torque when the case gets full, the capstan will burn the tape to itself from the friction.

What is needed after getting the cassette out is new belts, clean heads, clean capstan, clean or replace rubber pressure roller, adjust and torque the clutches (both sides) and lightly lube the capstan bearing without getting any on the upper capstan shaft. DO NOT EVER SPRAY ANYTHING INTO A CASSETTE OR TAPE MECHANISM!!! Except air of course. The amount of slippage and uniformity of torque each clutch hub has is critical and usually set using a special torque gauge cassette on the bench. Professional techs acquire a knowledge of this 'feel' and can set it by hand fairly accurately. End users do not acquire this experience readily.
The clutches are basically cotton pads pressed by spring adjustment against a flat disc.
The friction from the pad causes the clutch action. The compression and wear on the cotton pads wears them down and makes them thinner. This changes the pressure and surface drag on the clutch and causes the clutch to get weaker, on top of the belt stretch problem. Sometimes these can be re-adjusted, but often a new clutch pad is needed on one or both hubs. There are techniques to 'screw' with this but they are for the experienced technician only. Pad replacement and adjustment is the best solution.
There are direct drive motor clutches out there but they are strictly high end and not common at all.

Many times we'd see decks where the owner had gotten a new belt and replaced it but it still didn't work. The belt shape, cross sectional size and length is critical and often these were too tight or too big. Too little belt stretch and it slips or comes off the pulleys, too much belt stretch and the pressure stalls the motor and other bearings by side loading them too much. (these aren't ball bearings)

When everything is finally put right and clean again you can return to normal use to repeat the cycle again.

If you don't know what you are doing, I would send the unit in to someone that does because even if you get the tape out clean, the conditions that caused it are still sitting there, getting worse as time goes on. Either that or quit using it (after you get the tape out) or switch to a cassette adapter and use an MP3 player with it instead.

Leaving the tape in there with the radio powered on isn't such a good idea.

HTH

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Hello from Virginia,

Welcome Aboard!!!!!

Glad to have you with us!



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