I have screen lock problem on my television NASH 21'' color television NTV21NO1S

Hello, Alethea -

You will need to take your comment / complaint directly to Patricia Nash Designs:
https://patricianashdesigns.com/customer-service/

Best wishes.

Here is a great link for the manual:
http://www.manualslib.com/manual/323457/Protron-Pltv-4250.html?page=21#manual

Try page 21 through 25. There is no "factory restore" function, but you can adjust the hue and colors.

Hope this helps. PROTRON PLTV 4250 User Manual Using The Remote Control

color on raster screen problem like a yuk damage

do consult owners manual as this may be a auto demo mode that has been activated by accident.

last week i had an emerson 21 inch with built in dvd.,it was flashing colours.none of the front buttons would work.i unplugged the front buttons and plugged them back in again.set is working fine.ican not remember if i did it with the power on or off.try both.some how the front buttons were locking up the micro.

I have a 21'' NEC TV Screen and it about 3 year old. the colour has gone to yellow and green color and the red etc

Yes your handset is locked, Try and find out from where you got it the service provider it was got thou as for the age of this handset it should be able to be unlocked for free.
Nash

Try with 1147 (This one worked on my ONIDA TV) OR 5963 OR PRESS ZOOM BUTON AND VOL- KEY BOTH.

i have a beko tv which i want someone should help me find ser vicemode

Your parental lock is probably activated. That is most likely the V-chip doing its job locking out depending on the rating (PG,PG13,R etc) of the program.