stop cooler, the schematic diagram would be of great help

There is no scheme. Try to repair without a scheme.

Take measurements.

Maybe it will help you ab57.ru/schema.html

measurements taken at source:



voltage over input capacitor 180uF / 450v -> 185v ( o certo deveria ser em torno de 380V)
FSQ0165R Input Integrated Circuit:
voltage at pin 2 -> 6V
voltage at pin 8 -> 185V
voltage at pin 5 -> 85V

approximate voltage

Can the FSQ0165R integrated be the cause of the defect?

Study here





DOWNLOAD FSQ0165R : FSQ0165R.pdf

In order to be able to fix the font it is necessary to replace the following components:
R10, R11 -> 5.1 ohms
ZD1 -> Y6 (must be 18 v)
Q4 -> W2F (must be PMBT2907A)
Q3 -> W1P (must be Pmbt2222a)
Q1 and Q2 -> 07N90E mosfet

the w1p and w2f components just ordering what would take about 1 week for me to receive. If I could remove at least these two transistors from the motherboard or scrap board from the power supply, it could do the job a little faster.

Find a replacement for transistors W1P and W2F.

in place of 07N90E can I put the 2SK3878 or
  the W9NK70Z?

YES, 2SK3878, Transistor N-Channel 900V 9A.