Yamaha DX21 potential battery replacement

[mostofit268]

Hi there, I have a Yamaha DX21 I love messing around with, earlier today when I turned it on it had no sounds except for a few weird sounds that were no where close to the original, additional the screen had giberish for the names of the patches. from what I've already googled it sounds like a straight forward battery replacement which I do feel fairly confident I'd be able to do myself. From what I understand sounds like I need a CR2032 with solder tabs and to switch out the old one.

What I DON'T understand is how memory, patches, ect works. I'm not very knowledgeable about these things and am having trouble understand some of the more technical posts about loading, reloading, backing up, corruption and so on. I so far only play the synth as is and send it to a mixer. its making me question if I need to bring it to a professional..... however resoldering a battery? I got that no problem for sure. so my question is, am I gonna mess up my synth by switching the battery and turning it back on? I don't have any custom patches I've loaded from elsewhere, honestly I've just used the premade sounds and edited them and thats been enough for me so far. when I turn it back on will all those sounds still be there? I'm worried I'll accidentally erase everything the synth came with!.... but maybe not?? help ! sorry to ask such a basic question, thanks in advance

[meatballfulton]

The 128 factory presets in ROM will be retained after a battery replacement. The 32 presets and 32 performances stored in RAM will be lost...in fact probably lost already.

[Weirdofromouterspace]

however resoldering a battery? I got that no problem for sure.

That's really no problem, provided you have some basic soldering experience. I've done it on mine several years ago, and that was before I got deeper into SDIY. I didn't even have a proper workbench then and did it on my living room table .

Here is a short tutorial video (not by me).

I've just used the premade sounds and edited them and thats been enough for me so far. when I turn it back on will all those sounds still be there?

You could try and save your edited patches via a sysex dump before swapping the battery - if they are still OK, you can re-upload them, and if they're already damaged/corrupted, you won't lose anything that isn't already lost anyway.

The original factory presets/patches (plus tons of others) are readily available for free on the web, so there's nothing to fear either.