Hello Ragnar22,
Firstly, you need to make sure that you've replaced those diodes with the same types or equivalents as shown in the picture below.
To determine if the fault lies in the power supply itself or the problem is further down the line, you need to isolate the 24V rail.
This can be done by lifting one leg or removing a component down the line that supplies the rest of the set with 24 volts.
Once isolated, you need to attach a load to the 24V rail, as shown in the picture below. Polarity of the globe doesn't matter, but it has to be a 24 volt incandescent truck globe.
The 24 volt line may provide several sections to the telly, therefore you need to isolate each section in turn.
Lets say for example the 24V rail goes to a 12V regulator IC, you need to de-solder and isolate the "IN" pin of the device.
Its really a process of elimination to give you an indication of what part/s of the telly are causing it not to work, as well as causing D9 to overheat.
If you do decide to use any of my suggestions please let us know how you get on.
Good luck!!! :grin:
Regards,
Relayer