How do you open a Yamaha CX5MII/128?

Por altgraph

Supporter (5)

Imagen del altgraph

24-08-2021, 11:42

Hello! First time posting here since I recently got hold of a treasure trove of a MSX Yamaha CX5MII/128 with almost a complete set of Yamaha sound expansion cartridges in almost as new condition. So I want to get started with this beast and see what's underneath the hood and in what condition (for cleaning, recapping and modding purposes).

Just... How are you supposed to open it!? There are no visible screws, I haven't been able to find a service manual or instructions for the CX5MII/128 and none of the modding guides mention how to open it.

I assume it will be something really facepalm easy, but the unit is in such good condition with so few blemishes that if I can, I really don't want to add any more just by opening the damn thing.

So could anyone help me out here? How do you open a Yamaha CX5MII/128?

Login sesión o register para postear comentarios

Por st1mpy

Paladin (838)

Imagen del st1mpy

24-08-2021, 13:02

I think the service manual is Here

Por altgraph

Supporter (5)

Imagen del altgraph

24-08-2021, 13:44

Oh man, thank you! I'm looking through the service manual now and I think I got it now. It was as I suspected so now I'll dare try to pry it open. Smile

Por altgraph

Supporter (5)

Imagen del altgraph

27-08-2021, 13:05

This was easier said than done. :/

I've tried releasing the four "claws", but the top sits snugly and tight and the only thing that happens is that the screwdriver leaves slight marks in the plastic even if only the slightest force is used.

The service manual mentions a screw in the center of the bottom case, but there is no (visible) screw there. There's a round indentation with a really tight hole, but if there's a screw attaching to a standoff through the PCB on the inside, this is not visible and it feels risky to just jam a screwdriver through a dark hole, not knowing whether I'll damage something or not.

I'd really like if someone who has someone opened up a CX5MII/128 could pitch in here. I don't want to damage my case, but I do want to get a look at the insides.

Por Pencioner

Scribe (1480)

Imagen del Pencioner

27-08-2021, 14:44

when i opened my Yamaha i used this video - at the beginning Yamaha is opened. hope this helps

Por Alexey

Guardian (3239)

Imagen del Alexey

27-08-2021, 18:01

That's in Russian, but you can use Google Translate:

https://sysadminmosaic.ru/msx/yamaha_yis-503iiir/disassembly...