I've just spent the best part of the day inside my GF-9000 and after rebelting her all up and adjusting the tape head alignment (my FIRST time attempting this and it was a success!) and tweaking the motor speed I had her all ready to go back together, sounding great and playing tapes perfectly.

Then something happened. I have no idea what, but it was while the deck was running and I was listening on headphones. Just as I was about to power it down before I reassembled everything, the sound just stopped. The power light won't come on. But the deck runs perfectly. I just get no sound through ANY mode/input now.

I can hear the little electrical 'thump' when the deck engages and when I turn the power on and off, but ZERO else. I've spent the best part of 2 hours going through everything and it all looks as it should, the fuse is fine, it performs the same on batteries and AC.

Have I somehow blown the amp chip through accidentally shorting something? Any one have any suggestions or experienced something similar??

I'm at my wits end with this radio, I dearly love her and was elated to have her functioning 100% for the 5 seconds before things went awry.

I think I'm going to relax and have a few drinks now I think...

Thanks for reading, hope someone's got some ideas.



Rock On.

Ohh, I'm sorry to hear that Rick. I've had a similar thing happen to me with my Sharp GF-8989. I fixed the deck, and then POP, nothing. I replaced the fuse and it keeps popping. Since it stopped working, it's been sitting in the cupboard because I don't know how to fix it. I hope somebody here can help you. Maybe you could get a replacement board for it if someone's parting one out?

First of all , what headphone did you use?
I ask this because i blew the headphone amp in my mixing console once with a sennheisser headphone. The problem was that this headpnone has an impedance of 600 Ohm instead of 32 Ohm or something. Due to this 600 Ohm i had to turn up the pre fade listening volume almost to the maximum. The amp chip was blown.
Too low impedance is not good , but too high impedance is not good also.
Secondly , did you try to move the speaker /headphone switch a few times?

Hi Eddy, I'm using my Sennheiser PX-100's which are still picking up the 'thump' from the headphone socket fine.. and working in other things still. Reconnecting the speakers produced zero sound too. No hum, no nothing. I don't think the Gf-9000 has a speaker headphone switch, but I've flicked the internal/external speaker switch and all volume related controls alot.

I'd like the think the headphone section of the 9000 is robust enough to handle my little Sennheisers, the volum was on about 3 or 4 when it happened (hard to tell with the fron of the box off) but it certainly wasn'y cranked up high.

Thing is the amp/radio/line in section of her was perfect and never played up at any time before, even when being carried around running on batteries.

Thanks for the help guys. Great to hear from you too R.A.!!!


Rock On.

With the volume on 3 or 4 , i don't think it's the amp chip.
Did you try to connect something on the line out of the GF 9000 to check if you get sound from there?

Oh , something else.
Do you get sound from radio reception?
No sound from tape is maybe the record /play sliding switch on the print acting up

I tried the External Speakers and got a lot more noise and hum out of her. I could actually hear that it is still switching On with the power button (though the LED dosen't light), couldn't hear anything from the Line-Out however, possibly due to it's lower volume?

Still no sound other than the hum that increases and decreases when I move the volume up and down.

No sound from anything on Tape, Radio or Line In.

Thanks HEAPS for that suggestion Eddy!



Rock On.

Do you have a separate power supply to test it with? or just 10 D's .
If the power LED doesn't lit , my guess is that the inner power supply is too weak.
Maybe you can try to take a volt meter to check the voltage of it

The hum you mention can be caused by the power supply. The transformer is connected to 4 rectifying diodes . A smoothening capacitor is connected to these diodes ( 3300 µF)
If this capacitor has gone bad there can be hum and too low voltage. In some cases a bad capacitor can shorten the power supply.
I had that once with an old power amplifier.

I'm running it off mains power currently, works the same as on batteries.

A NEW discovery however, I tried recording on a tape, to see if radio/mic noise came though and was recorded to it, but nothing came through at all when I played it on another deck. It didn't even record over what was previously on the tape.



Rock On.

Might be the record /play switch after all.
Did you try to use some contact cleaner and move it a few times.

I did just that and noticed the lever wasn't hitting that switch. It didn't fix any problems now that it's aligned, however now when I press record I hear the 'powering up' noise that you usually hear when engaging Record.

Still isn't recording anything to the tape however. Now the internal frame is separated from the case I'm prepared for anything else that's suggested! Thanks again Eddy!



Rock On.

No problem .
I'm sorry that my tips were useless.
I really hope you can enjoy your 9000 again soon.
I really like this one even when owning the M 90.

Your tips were GREAT Eddy! It's still not fixed but I've got a lot more hope of resurrecting her thanks to you. Have a great weekend brother.



Rock On.

All the same for you

Hey Glue, I don't have this box but I can say most of the time if the LED power indicator will not light and your switches (Power switch) is clean not corroded, then your dc supply voltages are suspect. I would be using a volt meter to check voltages in and around the DC power regulation area something is going to be low. Either bad componet's (part or parts) in this area or there is something loading the supply down (short circuit) in another area so it can't produce enough voltage hence circuits don't fire up correctly hence no light no sound ect. This is where a schematic comes in handy. Wish I could help more but it gets a little tricky.

Some schematics would help a lot.
Could you put some photos of the Sharp ?.
Looks like someone is shorten the supply at some point. But if motor is running, not short at all.
Hum noise is a clue that poor supply regulation is present.

I would try to unpluging the mecha (motor, heads and power switch). You can still use radio to test the main board and power amp.
Unplug the speakers too. Test using headphones or line-out. I would unplug as much things as I could but keeping the main board functional in order to narrow the search.

If you can locate the rectifier (two of four diodes near de main cap) have a look if the diodes run hot. If yes, definitely you have a short somewhere.

It happened the same with my sony CF580. No sound when assembled. No led, no vumeter. Nothing.
When I touched the diodes from the rectifier they were very hot. I realized that I've made a mistake somewhere. Of course I unplug the boobmox.
The mistake was that the power switch of the deck was touching the chasis (gnd).

If do the same on batteries, don't insist.
D Cells have more current rate than the power transformer. If you insisit on running the boombox other thing could result damaged.

Try to use a 500mA DC transfomer (with a DC equal to the boombox supply) connected to the DC jack.
As 500mA is a little current, no risk on damaging another parts included the boombox tranformer.

a long shot , but maybe a check on the headphone socket , check its re contacting for speaker use when the jack is pulled out ???

Ok I removed the entire deck and it still performs the same way. Theres the 'thump' of it turning on and thats it. No action from any of the function buttons, nothing from the tuner.

To my uneducated eye all the power board elements seem to be running fine, nothing untoward and no excessive heat.

I've tried cleaning every connnector and have checked everything I'm capable of doing, looks like she's going to have to go to my repairer dude... shame, really thought I was on top of this one.



Rock On.

Do you have a voltmeter ?. Could you measure the DC in the main cap (the huge one, somewhere between 2200 uF and 3300 uF) ?.

Unfortunately I don't.. I'm ok with the physical side of things, but when it comes to currents and volts I'm very ignorant unfortunately.

Thanks for all your suggestions SUCCESS, I've really appreciated the input from everyone, even if she's still not working.



Rock On.