DX7 has no sound

This section is for all variants of the Yamaha DX series. DX1/DX100/DX11/DX21/DX27/DX27S/DX5/ DX7/DX7IID/DX7IIFD/DX7S/DX9/TX81Z/TX7

Moderators: Derek, parametric, Saul

User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Tue Mar 24, 2020 5:17 pm

I just tried to measure the pins of the top white plug together with the 0 i found in the bottom plug.
now the resp. voltages are 29,7V and 20,3V and 16,16 V

don't know if this helps...

(off topic: where can I make a signature for this forum?)
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 2097
Joined: Fri Oct 31, 2008 1:00 am

Re: DX7 has no sound

Unread post by Miks » Tue Mar 24, 2020 6:34 pm

Kropjesla wrote:
Tue Mar 24, 2020 5:17 pm
I just tried to measure the pins of the top white plug together with the 0 i found in the bottom plug.
now the resp. voltages are 29,7V and 20,3V and 16,16 V

Don't know if this helps...
Hmm - not really... the voltages should read +5 Volts, +15 Volts & - 15 Volts DC (= direct current) if measured correctly. Can you post a good pic of your multimeter's topview?
(off topic: where can I make a signature for this forum?)
Navigate to the user control panel -> Tab 'Profile' -> 'Edit signature'. But maybe it's not allowed yet to post a signature because you're still a new member here...
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500,
TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Tue Mar 24, 2020 7:33 pm

Which pins should I test?
Meter2.jpg
Meter2.jpg (32.51 KiB) Viewed 212 times
Last edited by Miks on Tue Mar 24, 2020 7:50 pm, edited 1 time in total.
Reason: orientation of picture altered
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 2097
Joined: Fri Oct 31, 2008 1:00 am

Re: DX7 has no sound

Unread post by Miks » Wed Mar 25, 2020 1:10 am

All black wires are connected to Ground (GND)
All brown wires are connected to +15 Volt
All yellow wires are connected to -15 Volt
All green wires are connected to +5 Volt

So turn your meter's switch over to 20 V= (left side of the scale) and connect the black lead to one of the black wires and leave it there! The red lead connect to one of the wires described above and read their value - one by one - and please post those values here. You only have to measure every color once.
Wires PowerSupply.jpg
Wires PowerSupply.jpg (31.84 KiB) Viewed 205 times
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500,
TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Wed Mar 25, 2020 6:49 am

After studying this page, i found that the black wires are 0
the brown are +15V and the green are +5V which is is what I measure
well: 14,88 V and 5.15V
Attachments
Schermafbeelding 2020-03-25 om 06.45.25.png
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Wed Mar 25, 2020 6:55 am

here it says yellow should be -15V Which is what I measure. (-15.22V)
That is why I got 30v between yellow and brown.
and -20,3V between yellow and green.

This adds up, so the power-supply seems fine.

O sorry I just read your post telling me the correct voltages. The page was still open and after my reply it reloaded.
anyway thank you, but this doesn't seem to be the problem.
Attachments
Schermafbeelding 2020-03-25 om 06.51.58.png
Schermafbeelding 2020-03-25 om 06.51.58.png (27.11 KiB) Viewed 197 times
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 2097
Joined: Fri Oct 31, 2008 1:00 am

Re: DX7 has no sound

Unread post by Miks » Wed Mar 25, 2020 9:07 am

Hi Steven,

yes, the voltages are looking fine.
That is why I got 30v between yellow and brown and -20,3V between yellow and green.
This adds up, so the power-supply seems fine.
Yeah - that's the declaration for those 'high voltage' measurings :)

From now on an oscilloscope would be extremely helpful... 8O
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500,
TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Wed Mar 25, 2020 9:11 am

while studying the circuit-diagram I would think the problem could be anywhere between ad-converter and output
but maybe thats simple?

since moving the volume slider doesn't make any difference (no added noise or anything.
so it seems the signal doesn't get to the output in any way

I only have an osciloscope app in my phone :(
maybe I know someone who can lend me one...I'll get back when I know more
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Wed Mar 25, 2020 9:22 am

When I test the battery with my multimeter it says 2,9 Volts (not 3,2 as the DX7 tells me)
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 2097
Joined: Fri Oct 31, 2008 1:00 am

Re: DX7 has no sound

Unread post by Miks » Wed Mar 25, 2020 9:27 am

That's ok - I just read that Yamaha says if the battery is not lower than 2.2Volt the memory chips are able to keep their content (at least as far it concerns the DX7's).
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500,
TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Thu Mar 26, 2020 3:07 pm

I've got a scope!
where do I begin?
User avatar Germany
Miks
Specialist Moderator
Specialist Moderator
Posts: 2097
Joined: Fri Oct 31, 2008 1:00 am

Re: DX7 has no sound

Unread post by Miks » Thu Mar 26, 2020 4:07 pm

Kropjesla wrote:I've got a scope!
Sounds good. Please let me see a pic of the scope's komplete! faceplate and another one with its accessories - which hopefully came with it - so I can determine the necessary settings for the measurings.

But let me first ask a few questions:

Is the synth already loaded with (some) sounds? Is it possible to choose between them? Are the voice's (=sounds) names appear to be shown correctly on the synth's display? Are you able to send sounds from a computer (whatever model) via Midi to the DX?
My (key related) gear (in alphabetical order):
Ferrofish: B4000+
Kawai: K1 II
Korg: M1 (up'd to EX, w/ 'Cool Blue'), M1REX (w/ 'Cool Blue'), Poly-800
Roland: D-50, D-110, D-550, PG-1000
Yamaha: AW1600, DX7IID (w/ 'Cool Blue'), EX5R, RM50, RX5, SY99 (w/ 'Cool Blue'), TG500,
TX-802, YMM2
Sector101: SYEMB05 (5x), SYEMB06 (3x), EXFLM2 (1kit), MCD Sweet16 (1x), DataBlade32 (1x),
WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Thu Mar 26, 2020 6:43 pm

its a labnation connected to a mac
https://www.lab-nation.com/
http://wiki.lab-nation.com/index.php/Ma ... ser_Manual
I do not have the logic analyzer cable
Last edited by Kropjesla on Thu Mar 26, 2020 8:18 pm, edited 1 time in total.
User avatar Netherlands
Kropjesla
Member
Member
Posts: 28
Joined: Sun Mar 22, 2020 4:33 pm

Re: DX7 has no sound

Unread post by Kropjesla » Thu Mar 26, 2020 8:11 pm

Is the synth already loaded with (some) sounds? Is it possible to choose between them? Are the voice's (=sounds) names appear to be shown correctly on the synth's display? Are you able to send sounds from a computer (whatever model) via Midi to the DX?
yes I reloaded the factory presets via a memory-cartridge, all the buttons work, I can change sounds, edit, rename etc.
I should be able to send sounds from my mac but I have to look into it...
User avatar United States of America
Angel0pdx
Posts: 4
Joined: Thu Mar 26, 2020 10:30 pm

Re: DX7 has no sound

Unread post by Angel0pdx » Thu Mar 26, 2020 10:43 pm

My recently acquired DX7 has no sound. Upon startup the screen finishes out with

internal voice
Int 1 Hammond B

But there is no sound through the output and to my PA, and with headphones in the headphones Jack I only get a crackle when I move the volume slider.

I know nothing about this synth, but I’m guessing there is a specific combination of buttons that tell it to play from the internal data and send sound out when the keys are pressed. What is that combination?
Post Reply

Return to “Yamaha DX & TX Forum”