Repairing Astec AA22750WR Power Supply: Fuse & Rectifier Diode Issues, UC3842T Voltage, Transformer

Welcome!
I am repairing the switched power supply as in the subject. Similar subject
When I got it, it was a fused network fuse that had a black sludge on the walls and one rectifier diode in the power rectifier was pierced.
Checked electrolytes, passive checked elements.
There is no tension at the exit. The network filtering capacitor is 315V. Voltage on UC3842T pins does not exceed 1V. Mosfet ok, there is no key signal. Can a transformer be damaged? I attach a picture with measured winding resistances

If the mosfet is operational, change this UC .... On the secondary side, the LEDs are functional?

mdm150 wrote:

On the secondary side, the LEDs are functional?

Yes
The chip is hard to desolder because it is glued with glue, but I can try it. I mean mainly for profitability, because if it turns out that it was good and the transformer was guilty then ...
It's hard for the scalak to work, as there is no tension. I'll try, see.

Are such transformer resistances normal? I do not know about impulse, that's why I asking

Damage luck is a rarity in these systems.

NIXIE_123 wrote:

one rectifier diode in the power rectifier was pierced.

- if defective, replace all LEDs.
Do you have a power supply voltage on pin UC3842? It should be around 30V. After such damage, the UC3842 will probably be replaced - the cost is small and the assurance that it is working.

Integrated circuit, power supply works.