DX7 IID won't power on
Moderators: Derek, parametric, Saul
Re: DX7 IID won't power on
Diodes are designed to pass current in only one direction. So, they should have a relatively small resistance measured in one direction and a much higher resistance measured in the other. I would not recommend using the 'continuity" mode of a multimeter which it sounds like you are doing if relying on the beeping sound as an indicator of resistance.
And, it is best to lift one end to isolate the diode from other components that might give you a false reading.
And, it is best to lift one end to isolate the diode from other components that might give you a false reading.
DX7 (MKI) w/ E! Card & S80 kb synths
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings
Re: DX7 IID won't power on
Did your DX 7 possibly even have an electrical short circuit?
If so, who knows what is broken then?
If nothing works ... ebay (or ebay kleinanzeigen) should help.
You may buy another DX 7?
Example:
https://www.ebay-kleinanzeigen.de/s-yamaha-dx7-ii/k0
Get it - ebay france etc. in france.
-------------------------------------------
Ok! I'm out of here.
That all is "something" for MIKS and other specialists.
Good luck! I hope it works!
If so, who knows what is broken then?
If nothing works ... ebay (or ebay kleinanzeigen) should help.
You may buy another DX 7?

https://www.ebay-kleinanzeigen.de/s-yamaha-dx7-ii/k0
Get it - ebay france etc. in france.
-------------------------------------------
Ok! I'm out of here.
That all is "something" for MIKS and other specialists.
Good luck! I hope it works!
Re: DX7 IID won't power on
My PSU is the VB78450 (north european), and I have a D8.
my beep is continuous. My multimeter is a fluke 115. actually, with a correct diode, the beep is very short. but there, according to the manual of the multimeter, with a continuous beep, the diode is in short circuit.
I can already try to change it, we'll see ..
my beep is continuous. My multimeter is a fluke 115. actually, with a correct diode, the beep is very short. but there, according to the manual of the multimeter, with a continuous beep, the diode is in short circuit.
I can already try to change it, we'll see ..
Re: DX7 IID won't power on
My spare PSU is the VB78460 (European/W-Germany/Australian Model) which also has the diode D8.
Not mandatory. There may be a capacitor in parallel with the diode which had failed. Did you take out the diode for measuring purposes?...the diode is in short circuit...
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
Re: DX7 IID won't power on
Ok, that's fine.
Here's where the 'missing' diode D8 belongs into the schematic
(they've simply forgotten to put it in the drawing...

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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
Re: DX7 IID won't power on
ok, I tested the diode D8 outside the circuit: it is ok. I will test the components around D8.
the schematic you are showing is not in the service manual. can you send it to me ?
the schematic you are showing is not in the service manual. can you send it to me ?
Re: DX7 IID won't power on
The schematic is in a separate PDF file in the yates.ca\DX7 FTP site
DX7 (MKI) w/ E! Card & S80 kb synths
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings
Re: DX7 IID won't power on
@ djazz75: Check your PM'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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
Re: DX7 IID won't power on
If you mean that yelloish goo (see arrow) - yes, that's normal. It's a kind of glue used to fasten electronic components to the pcb. No reason to worry...
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
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), WaveBlade 8MB Card (1x) & 1x Programmer Unit for WaveBlade
Re: DX7 IID won't power on
Ah OK. I suspected it was normal because all PSU photos on the internet have. thank for confirmation.
Re: DX7 IID won't power on
The leakage from bad Electrolytic caps will be a thin almost clear and often sticky liquid. More common to see is the top of the capacitor cylinder bulging upward. The glue you are seeing is as Miks said, normal.
DX7 (MKI) w/ E! Card & S80 kb synths
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings
WX7 & MDT (Morrison Digital Trumpet) MIDI windcontrollers
VL70m synth module w/ Patchman Turbo
Tx81Z, FB-01, RX-5, Roland XV-5080, Emu Emulator E6400 Classic - thanks to James M.
Win 10 Pro 64 bit with Focusrite Scarlett 18i20 & MOTU MIDI Express XT, Cubase9.5, NI - Kontakt5, Komplete11, IKMultimedia SampleTank 3 & 2.5XL, AAS Suite, BiaB 2016, Emulator X v2 & v3
"...there is no one absolutely essential truth for all people and ... every time I look at a coin, I instinctively want to look at the other side." -Peter Jennings