Sharp GF9090 APSS operation?

I have now got the tape deck on my GF9090 working, in terms of playing the tape OK, fast forward, rewind, etc.... but, the APSS doesn't work correctly.

When you press the APSS forward or reverse button it doesn't stay latched in.

I have took the deck out again and looking at the locking mech on the back it looks to be like it would be controlled by the solenoid on the back. Keeping tension on the locking bar until it finds the next track, the firing the solenoid to release and so play - does that sound right?

One small problem I have, if that is right, then I have something missing from the solenoid, as there is nothing inside it. I'd assume a shuttle with spring that pulls on the locking bar.

If anyone knows how this works, or has a photo of a GF9090 tape deck from the rear (or any GF9x9x I imagine) - that would help a great deal

The solenoid should look like this, taken 5 minutes since and the fully working deck from my 9090:



Now, when you had the plate out of the way for access to get the old capstan bushes out, did the circlip from the inner end of that solenoid go flying across the room? Mine did but thanks to an HOX metal detector application, I found it and shoved it back in. Result: Functioning search in both directions. I love the way that if you look at the light sequence for so long, the direction appears to change. Good old Sharp, playing with people's minds since the 1970s.


(Yes, the search keys are supposed to lock down, that circlip prevents the end of the spring from sinking, so taking the tension out of the thing).

Thanks Beosystem10 - that's excellent!!

I suspect mine was missing from the start as I'd have likely noticed a spool of that size when removing, but I did wonder!!

Would it be too much to ask for you to remove it and take a pic of the innards and/or pass on some dimensions?

Another issue these have with the music search is the 2 micro switches get dirty or oxidized. I usually take some sandpaper and sand both sides at contact points on these switches. If switches don't make good connection the solenoid doesn't work as this activates it


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Hallsy said:

Thanks Beosystem10 - that's excellent!!

I suspect mine was missing from the start as I'd have likely noticed a spool of that size when removing, but I did wonder!!

Would it be too much to ask for you to remove it and take a pic of the innards and/or pass on some dimensions?

Click to expand...

It wouldn't be too much, no, but may take a while as I'm not going to be at home much over the holiday weekend. I'll try to do that next Wednesday.

baddboybill said:

Another issue these have with the music search is the 2 micro switches get dirty or oxidized. I usually take some sandpaper and sand both sides at contact points on these switches. If switches don't make good connection the solenoid doesn't work as this activates it


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Click to expand...

Good point, and these can be tested for continuity before a solenoid assembly is located and fitted so the deck can be made ready to accept a solenoid as & when you find one.

Thanks guys. I had already cleaned up the microswitches, the reason the solenoid isn't working is because there is only the coil part there, the spool is missing!!

I haven't checked the signal to the solenoid coil, but I suspect it is working ok as when I use apss (holding buttons down), when it does sense the gap in the tape the vu meters give a little flicker!

It sounds like you are almost there! Keep at it.

baddboybill said:

Another issue these have with the music search is the 2 micro switches get dirty or oxidized. I usually take some sandpaper and sand both sides at contact points on these switches. If switches don't make good connection the solenoid doesn't work as this activates it


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Click to expand...

Sandpaper is bad to use though....

Bill meant 2000 grit automobile grade emery paper!
A few gentle strokes......
like you work on your nose...or eye lashes..

Well I used 1500 black sheet

But after rubbing alcohol and cotton swab didn't clean


Bad Bad Bill

I used a fibreglass cleaning pen - continuity was ok after that