Yamaha MU50 Battery Replacement

[Los974]

Hi everyone,
today my good ol' Yamaha MU-50 displayed a "battery low!" message on start up which seems rather normal as it is 24 years old

Therefore I would like to have it replaced. The trouble is that I can not find any info about the process to perform the replacement. Regarding this issue, the manual just shows "Bring the unit to your local Yamaha dealer or any other authorized Yamaha service personnel.". This is not possible for me, we don't have a Yamaha center anymore where I live, the small but beautiful Reunion Island in the Indian Ocean.

I am quite frightened to operate without any information as I read many bad issues (synth not booting after service, factory data lost, etc.) for other devices. In the meanwhile I could not find any specific procedure for MU50. I also tried to find information for MU80, the enhanced version of MU50, but found nothing. Any advice?

Best Regards,

Los

[Kentronix]

Not sure if this will be of any help but I have upped the service manual and schematic for the mu80 for you here :-

https://serial-number-decoder.co.uk/temp/

I couldn't find the procedure in there, as you mentioned this also says to leave it to qualified personnel but it does give you a list of 'donts' and the parts list tells you it should be a CR2450, which suggests its removable and easily replaceable but you wont know for sure until you open it and have a look. It has the disassembly procedure too and how to reset to factory settings if things go wrong

Hope its of use, if so save them as they wont stay up forever.

[Weirdofromouterspace]

Replacing a battery is usually not such a big deal.

First save/store all data you still require from your MU50.
Desolder the battery, solder in a battery holder (make sure to connect it in the correct polarity), and insert the new battery.
Upload the data you stored before, and/or do a factory reset according to the service manual.

That should be it.

Make sure to use appropriate ESD protection when opening the module (no big deal, wristband and possibly a mat will do). You don't want any sensitive parts being destroyed by ESD.

If in doubt, ask someone who's experienced with that kind of service - but again, replacing a battery and, if applicable, installing a battery holder is really not such a big deal.

[Los974]

Dear Kentronix and Weirdofromouterspace,
thanks a lot for your precious advices! I will try to open the device soon to see if it matches the documents shared by Kentronix.

Currently, I am hesitating a bit to proceed as I am not used to deal with electronics and I don't have any valuable data inside MU50 (factory settings and I use controllers and sysex to customize them). Therefore sometimes I tell myself that I could just use the device as it is, even if it performs a reset and display a low battery message on start. This may be less risky, isn't it?

Nevertheless, I will post here updates as soon as I get some.

Have a wonderful day,

Los

[Los974]

Hi,
something quite unexpected happened: the alert message doesn't show on start anymore.

The unit hadn't been turned on for a long time but these days, it is powered many hours per week. I don't know what to do: the battery should be replaced given its age, but I fear to "brick" the device by doing something inappropriate.

Regards,

Los

[Weirdofromouterspace]

The unit hadn't been turned on for a long time but these days, it is powered many hours per week. I don't know what to do: the battery should be replaced given its age, but I fear to "brick" the device by doing something inappropriate.

I wouldn't put too much trust in this. I suggest saving/storing all required data, then use the unit as usual, and be ready to do the battery change when it stops operating properly. Just be ready when it's required. It will come sooner or later .

[Los974]

Hi,
you were right, it started again displaying the message yesterday evening, while being powered.

Greetings,

Los

[keysfreak]

Not sure if this will be of any help but I have upped the service manual and schematic for the mu80 for you here :-

https://serial-number-decoder.co.uk/temp/

I couldn't find the procedure in there, as you mentioned this also says to leave it to qualified personnel but it does give you a list of 'donts' and the parts list tells you it should be a CR2450, which suggests its removable and easily replaceable but you wont know for sure until you open it and have a look. It has the disassembly procedure too and how to reset to factory settings if things go wrong

Hope its of use, if so save them as they wont stay up forever.

Thanks for those service manual links Kentronix. My MU80 has just started coming up with that battery error too so these will come in handy