Yamaha dx7 headphone output not working

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HelpPlease3
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Yamaha dx7 headphone output not working

Unread post by HelpPlease3 »

Hello,

I have recently been looking through some of my dads old things and found a Yamaha dx7. It was sitting in a lot of dust and was unused for a few years. I have tried to clean it as best as I can getting lots of dust and dirt out of it. I don't know a lot about electronics and stuff related to this. I am just starting to teach myself this about this. I had bought a 6.5mm to 3.5mm adapter to try out the headphone output. But whenever I play sound it comes out muffled and distorted, and some notes don't even make sound at all. I have been trying to service this for a few weeks now. Any help concerning this would be appreciated.


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Rara
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Re: Yamaha dx7 headphone output not working

Unread post by Rara »

Hi, first things to check are basic, I have not been inside a DX7 for a very long time.
you described what mine was like when I first bought mine.

Is there any sound from the line out? is it the same? Systems check with the self diag tool.

Open up the synth and check the voltage of the memory backup battery if your comfortable with a multimeter, mostly likely a flat battery causing some of the issues you describe.

Volume slider most likely full of dust and particles. If the slider is the open ended type a blast of air and fader lube will bring it back to life. if the slider is a sealed type, either desolder the slider dismantle clean and reassemble, or replace the whole slider. check the data slider as well.

Key contacts might have corrosion on them, will appear green with patches of white. clean those of with
cotton buds and CLR. If the corrosion is really stubborn very fine sand paper can take it off, IE 2000 grit.

Also possibly a blown transistor on the headphone output.

Rara 0-)


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HelpPlease3
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Re: Yamaha dx7 headphone output not working

Unread post by HelpPlease3 »

Hello,

Thank you for this information, but, I am really bad at electronics. I get worried I might break or forget where things go. I know it sounds nooby but I just don't know how to do this stuff. I will try my best to get what you've said done.


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Rara
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Re: Yamaha dx7 headphone output not working

Unread post by Rara »

HelpPlease3 wrote: Wed Oct 21, 2020 11:48 am Hello,

Thank you for this information, but, I am really bad at electronics. I get worried I might break or forget where things go. I know it sounds nooby but I just don't know how to do this stuff. I will try my best to get what you've said done.
*** IF your not experienced with electronics just yet, best leave any soldering until you are, or have a Tech
look at it later. To learn soldering or de-soldering use a dead PC motherboard to de-solder, remove and resolder the capacitors on the board first. There are plenty of instructions on the internet about soldering. once you get the knack of this, tackle a few beginner kits from jaycar or altronics.

Take photos of everything before hand of everything you do, screws or wires etc. use a bit of masking tape
as tags on the wires and write on them which wire goes were. If one is plugged into a board and right next to it or above the socket is printed CN10 or CN25 for example, write this on the tag so you know where it goes.

If you don't have it yet, have a read of the service manual before attempting any disassembly of the synth or the key bed.

https://homepages.abdn.ac.uk/d.j.benson ... nual_1.pdf

Rara 0-)


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