Fix TV to plasterboard wall. Already have 10mm holes in the wall.

None, cut out the plasterboard and fit timber noggins or plywood pattressing. I assume it's an internal stud wall?

 

Which fixings?

 

If it's an internal stud wall, you need to locate and fix to the studs. They should be spaced at 400mm centres. If the bracket for the TV will not reach across two studs then you can either fit a piece of ply to the studs over the plasterboard and fix the bracket to that or, of the TV is not large and the bracket is strong, just fix it to one stud top and bottom and use plasterboard fixings in each cornet to prevent the bracket rotating.

 

Or just buy a telly stand and put it on the floor. It's very hard to fall off the floor!

 

Dead easy after a nights drinking

 

@NewBornBaby

How heavy is the TV, and what type of bracket????????????

BIG DIFFERENCE depending on tv size / weight and a flat bracket vs a pull out type of bracket

If heavy and / or pull out bracket then do as Jord86 says.....

If small / lightweight tv and a flat fitted / non pull out bracket then these will fine if the plasterboard is sound and the holes are undamaged.
https://www.screwfix.com/p/easyfix-...6g7gIVBLDtCh1YgA4sEAQYAiABEgID_PD_BwE&gclsrc=

 

Then as Jord and Bob mention ............ Especially if you have a new born baby, or kids, or care for your wife, for as you have already found out, plasterboard fixings alone are not strong enough........

I've just had to re-fit a kitchen extractor at work as the installers just used two of these .

Bonkers.

 

That is going to need fixing back to the studs or additional noggins between the studs.. Toggle bolts, screw in fixings, &c are never going to be enough.

You will need to cut away plasterboard, insert noggins between studs and at the right position, then reboard and refinish.