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Problems with my GF-9696

thatoken - 2010-07-03 03:00

Hey, recently i got a new Sharp GF-9696 (26W Version). I got it quite cheap, because it was really broken. I managed to repair the Radio, Antenna, fixed the broken Case, got schematics and made a Line-In out of the Phono by bypassing the Pre-Amp (removed C111 and C112 and put the input on the switches SW101E-B and SW101E-A, and added some resistance for lowering the signal a bit). Now i have two problems left.

-First there is silent but annoying noise coming through the speakers (Rauschen). I is there in every mode, and had it before the Changes on the PreAmp (described above). Is it normal? Or what could it be? My Telefunken HifiStudio 1M for example is so damn silent in comparison to that. Think its not normal.

-Then the tape is not working. everything looks good from the mechanical side, only that motor does not start moving.

Would be happy for suggestions and hints.
Thanks a lot

superduper - 2010-07-03 13:44

Hmm. The sound of silence is annoying?

sinister - 2010-07-04 02:41

The sound of silence gets on my nerves

thatoken - 2010-07-05 00:48

man. i meant "gentle noise" or what ever. the word in german for it is "Rauschen". The translator says "hissing, noise, swoosh". dunno. im not a native english speaker, made a mistake, sorry. just thought to get some support here. maybe you better want to make jokes, dunno, but i am still happy about some hints. and the garfunkels sound of silence definitively is not annoying Big Grin

superduper - 2010-07-05 11:52

Hey Token. No joking here. But something must've been lost in the translation. Because it's not really clear from your text, what the issue is.

davebush - 2010-07-05 12:59

hey token....if your gonna use this forum, you need to have a very big sense of humour..........just ask lav about his nam... Big Grin

kid.sensation - 2010-07-05 13:27

he basically meant that there is some static in every single mode (radio, cassette, aux).

my question:

does the "rauschen" appear when you play music or just when there is no basic sound coming from the unit?

i got a couple of boxes that got a "brummen" ( Big Grin ) when there is no music on them -- it's simply the transistor-noise.

another question - is the static/rauschen like the static you get, changing a radio-station or is it "smooth"

i guess you cleaned all contacts and finished it up with good ol WD40?

still a sharp gf9696, even if it's a quality unit, cant be compared with a telefunken hifi studio in any way.

kid.sensation - 2010-07-05 13:38

in another thought it can also be a bad capacitor or similar caúsing this. but my knowledge in this case is limited as to hów to locate such things.

there are members on here that got tons of knowledge when it comes to electronical problems.

but most of them do not visit this place very often. you might also have a try in the tech-section of www.boomboxery.com as some do sneak in there more often than they do it here Smile

member FYI2972 is one of the first guys i'll recommend on here for knowledge in such cases.

kid.sensation - 2010-07-05 13:44

oh and for the motor - you might just try to find a replacement Smile

i do not know about the motors of the different GF-series, but another motor from another junker GF might work if it got the same power.

or ask for spare-parts in the wanted-section Smile

i got a rather bad GF-6161 -- if someone could tell that this motor would also work in your 9696 i'll gladly help you out as i think it's still working (other than the rest of the deck Roll Eyes )

thatoken - 2010-07-05 14:33

hey thanks a lot.
hmmmm now i changed all bigger capacitators of the line amp. nothing changed, but seems the sound now is somewhat clearer. or simply imagination.

yes, i get it in every mode and its static, so it should be something in the line amp? right? perhaps this is normal for a sharp, but my telefunken, my philips and nordmende were really silent in comparison. anybody here with and 9696 who can tell if its normal?
or perhaps its "just" degradation of the ICs, i dont hope so.
i noticed that the 9696 has some rather poor crossover network (only one cap as an high pass), im considering some optimizing there, perhaps with some second order high pass and low pass. i dont need to stick to the old everywhere.

To the cassette, the motor gets voltage when i try to play the cassette (round about 15 volts) but does not move. so i think the problem should be the motor. anyone an idea, where i can get a new one?

funny i payed only 70 euros for a perfect hifi studio 1 and more for that god damn damaged 9696 Big Grin

thatoken - 2010-07-06 03:50

ok that noise gets amlified, when i turn the music louder. now i believe it got little better after exchanging few more capacitators. hmmm

@Kid Sensation: that would be great, its a sankyo motor. have to look for the serial number later

muto - 2010-07-08 10:56

my 9696 is noisy also

thatoken - 2010-07-12 12:07

hey want to update this:

today i exchanged the crappy 6dB original crossover network (only one 4,7uF capacitator) with a selfmade second order Bessel (only 4 selfmade coils and 4 FKP-caps for stereo) crossover. And wow!!! the quality of sound got soooo much better, it really sounds great now. i just can recommend changing this to everybody, who is not happy with the original. you dont have to destroy anything, just some wiring and soldering.

and besides it got less noisy. i thought of switching the amplifier IC. but now im not sure anymore.

i managed to fix the motor (brushes were broken), so i do not need a new one. i just need that big flat belt, is there any good shop to get it in germany?

lav.loo - 2010-07-12 12:26

quote:
Originally posted by davebush:
hey token....if your gonna use this forum, you need to have a very big sense of humour..........just ask lav about his nam... Big Grin

Laugh Out Loud nice one dave Mad Big Grin Wink