Some keys not working on yamaha ypg 235 - Yamaha Portable Keyboard with 61 Touch-Sensitive Keys and General MIDI

SOURCE: What needs to be removed from my Yamaha YPG-625 to

DO NOT open the case unless you are aware of and comfortable with the fact that you could _destroy_ your piano. Easily.

Observe appropriate anti-static precautions. It should go without saying that this is an electronic repair, and dangerous voltages may exist inside the case.

1. Remove the stand if you have one
2. Lay the keyboard upside down (bottom up) on workbench
3. Remove all 90+ screws from the bottom of the chassis, including the 14 inside the speaker compartments
4. Carefully lift up on the bottom case part, taking not to damage the speaker lines
5. Unplug speaker connector and set lower case aside
6. LCD is mounted beneath main logic board
9in the center), my problem lies elsewhere, but competent and cautious service technique should lead you where you need. I would strongly recommend replacing the LCD assembly module, unless you are experienced in LCD repair.

SOURCE: hello, i spilt some smoothie

It is a lot of work to open and access the key contacts. Here is your service manual:

http://elektrotanya.com/yamaha_dgx-620_ypg-625.pdf/download.html

Scroll down to "get manual" and click on it to download. Ignore other download links on the page as they are for viewers and other software.