SHARP GF9191 PINCH ROLLER REPLACEMENT

How to do a pinch roller replacement of a Sharp GF-9191 Boombox

[@codebeat4192]

Thanks for the great excellent detailed video. The 40 years old pinch roller surface was harden like a rock. I also increase the tension a little by bending the pinch roller spring before install it again. Actually to service this you don't need to take the whole mechanism out and you don't need to remove the PCB. The spring can be easily removed and there is enough room to do just that. I used a pointy screwdriver to PUSH the pin out, very easy to do, this is only possible in one way/direction (push at the top). The replaced pinch roller doesn't have to look exactly the same, I have used one of 3/4 plastic inside and 1/4 rubber surface however approx the same diameter and width. Works great. Important notice to the surface of the new pinch roller: to avoid skewing of the tape, be sure the surface is not bold (like in your video at 8:11 - i have a few new ones with this issue). The surface needs to be flat, not (slightly) bold.

[@flyingfishnet]

I’m finding your videos very useful. Cant do electronics, but love the mechanical side. So THANK YOU

[@OldSchoolElectronics]

Thanks for watching. Some of these mechanisms are complicated. At least for me.

[@daftmanyoan3502]

Thank you for my Sharp GF 9090 ;)

[@jerrychan121]

thank you !good job!

[@OldSchoolElectronics]

Thanks!

[@vivremaintenant841]

good job👏

[@user-ld9en2td8q]

Cool man крутой чувак

[@ralphreinhardt6020]

You've done a very nice job here. I assume this cassette mechanism is very similar to the Sharp GF-9292? That's my next project, so new belts and pinch roller.👍👍

[@OldSchoolElectronics]

Thanks. I have never had a 9292, but both seem to be almost the same; the differences seem to be mostly cosmetic. Those 9292s are not that easy to find.

[@harmerfell]

Hi there, i’m french don’t mind my english. I have a sharp fg 9191 that i try to restore. I managed to fix the rubber goo wheels. But now i have an issue with speaker when i play the cassette turn but the sound are incredible low and sometime the speaker make loud acute sound (like bip) do u have and idea how i can fix that ? The speakers works fine with radio. Thx you

[@OldSchoolElectronics]

Bonjour. You should clean the record/playback switch/es. Or at the very least, move it/them back and forth a few times. Hard to say how many times; sometimes the problem clears up after 3 or ten times and sometimes not at all. The switch or switches are long and flat on the board. Close to the cassette mechanism. You can also spray contact cleaner in there and work it back and forth. With the power off. That can cause these funny noises. You should also do the same to all the controls if you can. At the very least l, do that long flat switch. If that doesn't help, do all the other controls/switches.

[@olivier0202]

Hello, My sharp9191 has stopped spinning. When I turn on the boombox and press play, it's start to spin but it's weak and it seems that it's blocked after a couple of rotations /seconds. do you have any tip on how to find what's wrong and what to replace?

[@OldSchoolElectronics]

Sorry, I am not on KZbin very often, therefore it takes me long to answer. Hard to say. I would check the belts, and inspect and clean all of the rubber wheels. Make sure they are not glazed, hardened, or cracked. Clean everything with isopropyl alcohol. Also check the little rubber pulley on the capstan, which is a long, thin, and shiny metal rod. Make sure the motor spins freely when the belt is detached from the motor pulley.

[@codebeat4192]

Sticky goo mess on the capstan, next to the take up reel rubber wheel that contacts the capstan when pressing play.

[@jmmbos]

The same kind of rubber that was used in the Optonica RT 7000 and probably in some other Sharp/Optonica models . Very strange and bad compound . Never seen anything like this , with all these cracks . I think the pressure of the spring was maybe too high also.

[@OldSchoolElectronics]

Thanks for your comments. I don't know about the pressure of the spring. You arw probably right; it must be the material. The Sharp works great now; the woman that has it uses it often (she still has cassettes) said it still works great. These boomboxes have seen a lot of use and abuse, too.

[@viantdf4256]

my gf 9191 pause button doesn't work, how to repair ?

[@flyingfishnet]

Why dont you put the oil on the inside of the pinch roller?

[@OldSchoolElectronics]

I always put a small drop of oil there. Maybe I left that out of the video; could be I accidentally edited it out or forgot to film it.

[@aussie54]

What is the diameter of the Pinch Roller please?

[@OldSchoolElectronics]

I can only tell you about my replacement roller since I no longer have the service log for this. The outside diameter is 13 mm and the diameter of the hole seems to be 2 mm. Since I don't have a micrometer, I had to eyeball this with a ruler. But they are for sale on eBay Germany; not that cheap, but the seller is reliable and also ships international, although not everywhere. The seller was called revox_de.

[@aussie54]

@@OldSchoolElectronics Thanks for your reply. I have since been able to find that the Diameter of the Original Sharp Pinch roller is actually 13.3mm while the diameter of the replacement (made in China) rollers are 12.8mm. I recently held both in my hand and I can clearly see the difference in diameter. For both, Yes, the hole is exactly 2.0mm and the width of the rubber is 6.0mm while the width of the hub is 8.0mm.

[@OldSchoolElectronics]

Cool! Thanks for all of these infos! I am sure they will help people in the future. I am not even sure I had the original specs written down since the old ones are out of spec due to wear.