Beko Z1J194-11 PSU 12V OK 24V Low at 17V

[mongoose2010]

Hi
wonder if anyone has any ideas
I have a Beko Z1J194-11 PSU in a 32" Beko
with no Picture
The standby light comes on  and it reacts to the remote
testing the PSU the 12V rail is ok but the 24V rain is low at 17V
I tried putting my bench PSU on the 24V and when I did that the picture came up ok
I tried fitting a PSU repair kit from ohms supplies which replaced the transisters and regulators
and I replaced the 400v smoother and the 4 elcrolytics caps

but still all i get is 17volts on the output

any ideas?