Ok, now are all capacitors on the power supply unit and the Display PCB are changed.
Please check if the are some more capacitors on the mainboard which are may be faulty because the display circuit has to get the signal Information from the integrated graphics card on the mainboard. This could be also the cause.
May be the Mainboard uses this critical capacitors for other functions.
Otherwise it will be more difficult to find the failure because you have to check the display PCB circuit in more Detail.