Help, need some brains - GF-8989

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wowminister

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May 8, 2011
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While checking my tape deck on the GF, I pressed play and nothing happened.

Ok, no probs I thought, but now I have nothing to the box at all, all power lost.

Still hear the transformer humming when plugged in, but no power to radio or amp.

Any ideas ??

Cheers

Tim

PS no smoke or funny burnt out smell.
 

baddboybill

Member (SA)
Jul 14, 2009
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Hudson Florida
It could be as simple as cleaning your switches with deoxit and working them back and forth a hundred times or so, as for the deck a good cleaning plus rebelt and the Sharps also have issues with the capstain shaft tiny rubber wheel which melts after years of use/nonuse...see members Monchito pic :-D

 

wowminister

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May 8, 2011
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Well looks like its the fuse, got it out and will head to electronics shop to see if they can help.

BUT

put batteries in and comes on, LED's, tape drive etc, but now no sound at the speakers ????
 

Fatdog

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May 3, 2009
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Be sure to clean the volume pot and selector switch. ;-)
 

bobdog

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May 11, 2011
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Narrowboat on the River Soar U.K.
Wowminster,
Be worth checking that the motor hasn't seized if it killed the fuse when you pressed play. Just gently turn the capstan flywheel by hand and look at the motor spindle to see if it rotates.
Not sure if this model has them, but Sharp sometimes used panel mounted fused that looked like transistors......small black rectangular lump approx 5mm x 3mm x1mm and marked on the panel as CP01 (circuit protect 01) or 02 /03 etc...
.
And .....another protection device was the fusible resistor....usually about 1ohm, 1/4watt and marked on the panel as FR01 or 02 or 03 etc..

Hope this info helps....
 

wowminister

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May 8, 2011
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The tape drive looks ok (from battery). I will be getting a replacement fuse tomorrow so I can try the mains again.

As for no sound, I will try cleaning the vol and selector pots, but as Luke says to Han... I have a bad feeling bout this ... I think he said that.

PS.

No sound from the headphone jack...
:huh:
 

bobdog

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May 11, 2011
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Narrowboat on the River Soar U.K.
Another trick to try....
If you can identify the output chip (s) ,not sure if it's one or two on this model, switch it on, and then lick the tip of your finger and run it over the solder connections of the chip. It's only low voltage so no danger, if there is power to the output stage then you will hear buzzing from the speakers. If still nothing then you probably have a feed missing and it's back to checking fuses and CP's !!
If it buzzes then probably faulty/dirty switching somewhere down the line.
Good luck!
 

Jboogie2384

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Sep 30, 2010
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I have an 8585 I'm parting out. I think they look the same. It sounds like the amp chips might have blown :sad: hopefully these are the same and I can ship them to you if needed. Let me know.
 

JVC838

Member (SA)
wowminister said:
Will do. Thanks for that.

Need a manual to find where those Amp chips are :hmmm:
I don´t want to be impolite, but if you cant identify the Amp-IC , you have no experience to change the chip.
You need a special soldering iron, a desoldering vacuum pump and so on.

Please try to find a technican, who repairs classic electronics.
 

wowminister

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May 8, 2011
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No that's ok.

I would try and get a technician, but the problem is that it would cost more than the box is worth (managed to get it for £10).

I have the equipment to had as I work with computer repairs, but older electronics are new to me.
:hmmm:
 

bobdog

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May 11, 2011
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Narrowboat on the River Soar U.K.
Output chip is usually bolted to a bloody great heatsink on the main PCB, looks like a black rectangle about 50/60mm by 30/40mm with a mounting bolt running through it either side .
Will have an ID number on it, possibly three letters followed by numbers....TDA4600.or something like that....
If you put these numbers into a google search it should tell you what that particular IC does so you can confirm that you have the right part.
Should get you in the right direction mate !!
 
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