If i watch pdf of this board
715g813-1 Ver:C i see
U4KB80R 800v/4a

Where i keep stuff from this monitor i have pbl405 which should be faulty(desoldered from the board) and one working gbu405.

The questions :
why in documentation there is diode with 800V but on board most probably was 600V
i will put the 600V. If something goes wrong only BD will goes faulty or not?

thanks

 

Probably they got a better deal on the 600V bridge rectifiers, 600v on a 230V ac supply is fine, even 400V will do.

 

and the next question - shorted fr107. In the shop they had not such.

Fr107 is fast recovery rectifier 1000/1
1n4007 is only rectifier 1000/1

Will it do the job?

 

No, try Uf4007

 

There is no real reason not to put a higher voltage bridge rectifire in there. I would not use a 400V one on 240VAC supply. That does not give enough headroom for tranzients. Higher is better. It giver you a more robust power supply so it should be more reliable.