Yamaha DX7 II-D power "restart" problem

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nuttelaboi
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Fri Dec 07, 2018 12:21 pm

Miks wrote:
Fri Dec 07, 2018 12:09 pm
nuttelaboi wrote:
Fri Dec 07, 2018 11:46 am
I'll try to put new *.syx files to DX7 and see, what'll happen. :)
Yes, good idea. But on the other hand - I (personally) have never heard or experienced that a 'broken' syx-file can cause such an issue like this sporadic reset of a DX7... :think:
As I said before, the problem is, that this malfunction is almost untraceable. It happens sometimes after 8 minutes, sometimes after 20 minutes, sometimes it does not happen. Synth doctor said, that that's the worst kind of problem because he cannot simply trace it. We thought it's due to the battery replacement, but it has to be something different. Guess I have to live with that until something blows in it and the cause of the problem will be certain (I hope this won't happen).
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Fri Dec 07, 2018 1:38 pm

Hmmm - maybe the power supply has a thermic problem... and therefore sometimes 'produces' a glitch which resets the synth... :think:
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
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Fri Dec 07, 2018 3:25 pm

Miks wrote:
Fri Dec 07, 2018 1:38 pm
Hmmm - maybe the power supply has a thermic problem... and therefore sometimes 'produces' a glitch which resets the synth... :think:
It can be this, but who knows. Anyway, thanks for your replys, Miks, was really helpful :)
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Fri Dec 07, 2018 4:01 pm

You're welcome! :)
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
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Sat Feb 02, 2019 7:29 pm

Miks wrote:
Fri Dec 07, 2018 4:01 pm
You're welcome! :)
Miks, I arranged a meeting with my friend, who recommended me to swap out all electrolytic capacitors in PSU. Do you think it's a good idea? Maybe some of the caps is causing the trouble, what do you think? Is it hard to get into the PSU od DX7 II? I know that mk1 DX7 is really easy to open, but what about the mk2? And what electrolytic caps should I use? Are there any of the electrolytic caps outside of the PSU? :think: :think:
I found this on the other forum (https://www.muffwiggler.com/forum/viewt ... 856ebe3e94)
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Sun Feb 03, 2019 12:00 am

nuttelaboi wrote:
Sat Feb 02, 2019 7:29 pm
Miks, I arranged a meeting with my friend, who recommended me to swap out all electrolytic capacitors in PSU. Do you think it's a good idea? Maybe some of the caps is causing the trouble, what do you think?
If it were my synth I would go this way - and I already did this on my DX7II/D :wink:
Is it hard to get into the PSU od DX7 II? I know that mk1 DX7 is really easy to open, but what about the mk2? And what electrolytic caps should I use? Are there any of the electrolytic caps outside of the PSU? :think: :think:
Unscrew the bottom of the synth and you're already there - no big deal. I recommend to replace ALL of the electrolytic caps. If you haven't done yet please read this entire thread:
viewtopic.php?f=35&t=11766
- it contains some useful informations that may be of help...

And yes, there are some more elec. caps on the mainboard...
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
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Sun Feb 03, 2019 12:59 am

Unscrew the bottom of the synth and you're already there - no big deal. I recommend to replace ALL of the electrolytic caps. If you haven't done yet please read this entire thread:
viewtopic.php?f=35&t=11766
- it contains some useful informations that may be of help...

And yes, there are some more elec. caps on the mainboard...
Yeah I found that article already. The list of the elec. caps you wrote to that thread is complete (including those caps located at the mainboard)? Could you tell me (approximately) how difficult is to replace all elec. caps in DX7 II? Will it take a lot of time? Is it hard to get to the mainboard?
Thank you again for your time and replies. It is very useful for me. :wink: 0-)
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Sun Feb 03, 2019 1:39 pm

nuttelaboi wrote:
Sun Feb 03, 2019 12:59 am
The list of the elec. caps you wrote to that thread is complete (including those caps located at the mainboard)?
No - those I've listed there are all located on the psu.

These are the electrolytic capacitors on the mainboard:
C5, C6, C7, C8, C10, C30, C37 = 1µF/50V
C13 = 2,2µF/50V
C38 = 4,7µF/16V - new recomended type: 4,7µF/25V
C47, C50 = 22µF/16V - new recomended type: 22µF/25V
C56, C58, C60 = 100µ/16V - new recomended type: 100µF/25V

There are several on the YA3 board which you don't have to touch.
Could you tell me (approximately) how difficult is to replace all elec. caps in DX7 II? Will it take a lot of time?
Oh - I have no idea how to estimate how much time it will take - it very much depends on the soldering skills & tools the person has excecuting this work! If you're unsure how to proceed leave this delicate task to an experienced person! 8O
Is it hard to get to the mainboard?
Turn the synth over, unscrew the bottom and you're there. Then you'll have to remove all the screws holding the mainboard (three on the pcb itself, two on the cartridge connector and four on the backside of the synth's housing) and disconnect all the cables & wires. Don't forget to 'mark' all connectors/cables so re-assembling will be easier. It's recommended to take a lot of pictures while taking the synth apart - they can be of great help during the re-assembly process... :wink:
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
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Sun Feb 03, 2019 2:13 pm

These are the electrolytic capacitors on the mainboard:
C5, C6, C7, C8, C10, C30, C37 = 1µF/50V
C13 = 2,2µF/50V
C38 = 4,7µF/16V - new recomended typ: 4,7µF/25V
C47, C50 = 22µF/16V - new recomended typ: 22µF/25V
C56, C58, C60 = 100µ/16V - new recomended typ: 100µF/25V

There are several on the YA3 board which you don't have to touch.
Thank you for the list.
Oh - I have no idea how to estimate how much time it will take - it very much depends on the soldering skills & tools the person has excecuting this work! If you're unsure how to proceed leave this delicate task to an experienced person! 8O
My friend is very skilled in this particular area. He is studying electrotechnical college. His hobby is repairing old radios and old PCs.
Turn the synth over, unscrew the bottom and you're there. Then you'll have to remove all the screws holding the mainboard (three on the pcb itself, two on the cartridge connector and four on the backside of the synth's housing) and disconnect all the cables & wires. Don't forget to 'mark' all connectors/cables so re-assembling will be easier. It's recommended to take a lot of pictures while taking the synth apart - they can be of great help during the re-assembly process... :wink:
Thanks for tips, I'll take the pictures, will be helpful.
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Sun Feb 03, 2019 3:13 pm

nuttelaboi wrote:
Sun Feb 03, 2019 2:13 pm
Thanks for tips, I'll take the pictures, will be helpful.
You're welcome! Let us know how you go on, would love to hear the outcome.

A hint: I would start to completely replace all elec.caps on the psu first - this often (but not always) cures such symptoms as the "Yamaha DX7 II-D power "restart" problem"...
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
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by nuttelaboi » Sun Feb 03, 2019 4:14 pm

A hint: I would start to completely replace all elec.caps on the psu first - this often (but not always) cured such symptoms as the "Yamaha DX7 II-D power "restart" problem"...
Thank you for this hint. My friend told me that he'll do it in this order just before you answered. :D He ordered all elec. caps you noted (PSU+MB), guess we'll repair my DX7 approximately at the end of the month (FEB 2019). DX deserves to get a new life.
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Re: Yamaha DX7 II-D power "restart" problem

Unread post by Miks » Sun Feb 03, 2019 4:16 pm

nuttelaboi wrote:
Sun Feb 03, 2019 4:14 pm
DX deserves to get a new life.
Absolutely - I'll keep my fingers crossed. 8)
My friend told me that he'll do it in this order just before you answered.
Good boy! :wink:
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
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