Yamaha DX21 loosing data when turned off

A few important things you need to know before registering and posting on our forum.
Najrob
Posts: 3
Joined: Wed Oct 11, 2017 8:41 am
Macedonia

Yamaha DX21 loosing data when turned off

Unread post by Najrob » Wed Oct 11, 2017 9:20 am

Hi!
I currently have two Yamaha DX21's and one in the past that i sold because of the same issue: When turned off for longer than half an hour or so , all the 32 sounds that are stored are gone , so i have to reload them again and again. They have new batteries installed and the memory protection turned on. What could the problem be?
Thank you for any help!



User avatar
Miks
Specialist Moderator
Specialist Moderator
Posts: 1331
Joined: Fri Oct 31, 2008 1:00 am
Contact:
Germany

Re: Yamaha DX21 loosing data when turned off

Unread post by Miks » Wed Oct 11, 2017 11:13 am

Hi Najrob,

most likely the internal battery (coin cell, 3volt) has given up due to her age. A weak battery causes a lot of different 'funny' behaviours especially on Yamaha synths. You (or a tech-savvy person you know) should open the DX and measure the voltage of the battery. If its less than 2.6 volts its recommended to replace the cell. After the replacement run a factory reset and reload your sounds (from cartridge or via MIDI from a computer...).

Hope it helps - please report back your findings...

Best,
Miks

Edit: just saw that you've already replaced the batteries - please DO check the solder joints carefully again - sometimes there's a bad solder joint that causes this issue...

Do you have the service manual?


My (key related) gear (in alphabetical order):
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


http://rescuer-uslar.de/
https://www.facebook.com/Rescuer.Uslar/

Najrob
Posts: 3
Joined: Wed Oct 11, 2017 8:41 am
Macedonia

Re: Yamaha DX21 loosing data when turned off

Unread post by Najrob » Wed Oct 11, 2017 4:03 pm

Hi Miks ,
Thanks for the prompt reply.
Yes, i do have the service manual ... apart from schematics and parts list there're no instructions on how to solve certain problems. But , bad solder joint makes sense to be a possible "suspect".



User avatar
Miks
Specialist Moderator
Specialist Moderator
Posts: 1331
Joined: Fri Oct 31, 2008 1:00 am
Contact:
Germany

Re: Yamaha DX21 loosing data when turned off

Unread post by Miks » Wed Oct 11, 2017 5:31 pm

Good to see that you have the schematic - please see section H-1 (Memory Backup): B1 is the battery, please check D2 and the electrolytic capacitor (4.7µF/16Volt). One of these may be defective (cap may be leaking/may be bulged). I suppose that 'someone' draws too much current and thereof your battery is getting discharged.

If the synth is switched ON the memory gets supplied (at Pin24) with 5 Volts across Tr3. If the synth is turned OFF the memory gets supplied from B1 -> D2 -> Pin24 (IC 4, 5 and 6) so it holds the content (sounds) stored in it. The capacitor 'buffers' that voltage. When the DX is OFF you should measure around 2.8 Volt or more at Pin24 of the memory chips (if the battery is good!).


My (key related) gear (in alphabetical order):
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


http://rescuer-uslar.de/
https://www.facebook.com/Rescuer.Uslar/

Najrob
Posts: 3
Joined: Wed Oct 11, 2017 8:41 am
Macedonia

Re: Yamaha DX21 loosing data when turned off

Unread post by Najrob » Wed Oct 11, 2017 8:00 pm

Aha... this is something very concrete. I'll check all these things over the weekend when off from work, and let you know about the result. Thanks for your kindness and help, i'm very impressed to be honest . God bless.



User avatar
Miks
Specialist Moderator
Specialist Moderator
Posts: 1331
Joined: Fri Oct 31, 2008 1:00 am
Contact:
Germany

Re: Yamaha DX21 loosing data when turned off

Unread post by Miks » Wed Oct 11, 2017 8:30 pm

My pleasure! If you have further questions just fire away - and we'll see if we can bring your DX 'back to life'... 0-)


My (key related) gear (in alphabetical order):
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


http://rescuer-uslar.de/
https://www.facebook.com/Rescuer.Uslar/

Post Reply

Return to “Please Read BEFORE Registering On The Forum!”

Who is online

Users browsing this forum: No registered users and 0 guests