Went to listen to the radio on my 777 a little while ago and now there's no sound at all. I noticed a couple of times before that to get the radio to work after turning it on at the power switch I had to press the play button on the tape deck and it would then come on.
It did this earlier and then when I tried to play a tape it played for a bit but then made a weird noise and now nothing works at all.
The red light works above the power switch as does the VU light when I press the meter/light switch but the VUs don't move to show the battery level. There's no sound or response at all when I move the function switch.
There is a faint hiss from the speakers which doesn't increase at all when I turn up the volume.
I've checked inside for detached connectors but they're all OK.
Any advice would be much appreciated.

Forgot to mention that there has always been a bit of static on the volume control at the top end and when I now turn the knob the crackling is still there so it's not a fault with the speakers.

That sounds a lot like the problem I had with mine when I first got it. It turned out to be the power switch. Here's my old post:

http://stereo2go.com/eve/forums/a/tpc/f/8596027254/m/12...711018764#8711018764

That would be the first place I'd check. My method of repair won't necessarily be needed, but it should give you a direction needed.

Thanks Fatdog.
The switch is allowing power through as the red light comes on brightly, the decks both work and dial light is OK. There's just no sound from either radio or tapes and the VUs don't move at all.
When I turn it on with the switch there is the usual soft thump through the speakers as normal but nothing else.

OK, I've just given the power switch a good clean with spray and compressed air.
I had a look at the transformer board and noticed that some idiot had wrapped a thin piece of wire around the fuse to bypass it as it was blown, I have now replaced it with a good one and tested the BBX again but it's still the same as before.
I have also noticed that the static on the volume control comes from both channels even when I adjust the balance knob, it this normal?

Perhaps try an external input to try and get some sound? Can you hear anything at all when you move the selector switch ? Just slightly ? On the PCB you can see 4 (i think) connectors all seated correctly on the board ? Follow those backwards to where they go and check the joints for any dry soldering. These few things might lead to something.

Thanks for your help docs.
I have stripped it all down and checked all connections and joints but they're all OK.
Moving the selector switch doesn't make any sound whatsoever, not even any movement on the VUs.
There are two amp chips so I don't think that they could have both stopped working at the same time.
I have also noticed that the green dubbing light doesn't come on any more.

sounds like something has blown on the pre amp board, have you tried it on headphones amanda?

Hi Tim,
I've tried some external speakers but they don't work and neither do headphones. I hope someone can help me to fix this.
The components around the amp area all look good. Maybe I should try changing some of them, can anyone advise me where to start?

If frank jiang was still around he could get this settled,have u tried pm him..or ask the mods for a email adress or something.He has a few gf's in his arsenal

Hi Jimski,
Thanks, I'll send Frank a PM.

No reply from Frank.
I called in my local repair shop today and described the situation, the guy said it sounds like a preamp issue especially when I said the VUs don't move. He suggested I check all the transistors on the amp board for shorts which I did but they're all OK. I can't see anything burnt, broken or disconnected anywhere.

Hi fuzzyduck on the amp pcb by the 2 ics there is a fuse f801 t315ma have you checked this is ok also there is a transistor Q110 this is the 15v supply rail this transistor is close to Ic114 on the main pcb. i have had this in the past the same problem vus dead no sound.If fuse is ok check the supplys on this transistor.
Happy

Hi Happy,
I can't see any fuses on the amp board, the only one I can see is on the power supply board.

I checked Q110 for short circuits by setting my test meter to ohms and probing the legs for a short circuit, it seems OK. I don't know any other ways of testing transistors.

hi fuzzyduck on the amp board towards the output sockets there is a connector called cnp803 this is the audio signal input to the amp stage,next to this hidden by the heatsink for the ha1392 output ics is the fuse f801 if this is blown will give you the same symptoms of this fault.If you also check Q110 with your meter check each pin,there should be 14v,14.7v and 15v. Let me know if these reading are there and also if you have located the hidden fuse behind the heatsink.
happy

Hi fuzzyduck i didnt realise you have the gf777z this does not have the second fuse in it only the gf777e does.
CHECK PM

Thanks a lot for the info Happy.
The 777s in your avatar, are they all yours?

hi fuzzyduck yes thy are mine but minus 2 which i sold,this picture was taken ten years ago,the most 777 i had were back in 2002 i had 8 now i have 3 777s and 1 767.
Happy

Great news, my 777 has now got his voice back again!
The fault was due to bad transistor Q110 next to the VU adjustment pots on the big horizontal circuit board.
Huge thanks go out to Kittmaster, Eddy and JVC Floyd for all their patience and help with getting the babe fixed and to Happy for his help and for supplying the new part.

Great news well done all.

Great news to see!

Great news!!!

Awesome !!
Now thats what I call teamwork

Great news Amanda.
I'm glad that you can enjoy your 777 again

Great news amanda im happy 4 ya

"... give me a happy ending every time!"

Wuhoo!!! Great to hear, we all know how hard you worked to get that going in the first place, so it's amazing the "team" can help you get it going again Another "grail" saved

Thanks guys.
It's such a good feeling knowing that so many folks are willing to help out on here, this is a great place!

thats awesome new fuzzyduck i'm glad you got it sorted out