Can I replace the screen on a hitachi 57f510 myself?

It may have to do with the Magic focus if that model has it: auto convergence and if fails a indication can appear on screen. The Magic focus if in play would be a flashing sequence moving to different areas of the screen in sequence.

cannot repair. it is a cosmetic blemish. you can replace front panel but is usually not economical to repair.

The part is called the screen assembly.

It is available at encompass parts
https://www.encompassparts.com/webwiz/wwiz.asp?wwizmstr=WEB.SEE&partnumber=5930164&smodel=57F510

and UED

http://www.ued.net/ued/searchResults.jsp?searchStr=57F510&d-16504-p=36&mfgCode=HIP&searchType=model&listParts=Y

If your TV looks 3D, warped, or distorted it likely has a convergenge problem.
If however it just looks dull, washed out, redish, greenish, or blueish or if it looks like objects on the screen have halos the fluid in the lens has soured.
You can search google for parts or you can get the parts with repair instructions from sites such as www.TvRepairKits.com

You may well have either poor contact on the tube base of the colour that is missing or a poor contact in the tube itself. The latter is not repairable.

Neither - it's a CRT projection tv - the oldest form of projection, an obsolete technology .
Full user manual if you need it
http://dl.owneriq.net/9/996c22bc-3680-44cf-88f8-ec6c4ffbb7b0.pdf

Here's a link to order the original Hitachi protective screen for this model (57F59A) from a major parts distributor:

Hitachi 57F59A Replacement Part Protective Screen / Ultra Shield

had 57f510, not working. i need your help. I turn it on and led light come on and disappear and nothing shown. what should i do?

Does the menu come up if so you need to change you inputs.

The Hitachi part number for the screen assembly for the 51G500a is KR02844. You can call a Hitachi parts distributor and see for yourself how much those things cost, but I warn you they are not cheap!