Try reposting this in:

sci.electronics.repair

wrote:
Greetings from Colombia.

Sometime ago, I bought a Samsung TV CL 21k40MQ, chassis K69C.
Recently, the screen looks slightly pincushioned and the image
vibrating near to the corners.

I've searched in Google, and found the comands to go in the service
mode from remote control. (Mute 1 8 2 Power). However, in this menu I
could not find nothing about the pincushion effect. I suppose that
this problem requires to open the TV. My question is, ¿can I fix this
easily, or I will have to take it to the technical service?

Thanks in advance...