Thank you all for your answers.
The truth is that it is a pleasure to be able to receive help, from anywhere in the world (Internet wonders)
Hi amyk, I'm not sure that those values ??are the tensions. I do not have ESR tester, but if I have capacity tester, only. However you are right, I will follow your advice to change all the capacitors.
Hi CJay, I thought the problem was only in the power supply, but you're right, I'll replace the electrolytic capacitors, and I'll charge the output with some resistors.
Hi PAOPBZ, If on pins 8,7,6, and 5 (Drain) of the IC, I have the 300 V dc, but when I look at them, I see that the reading of the meter does not stay fixed.
Hello Armadillo, the voltage (measured with a digital voltmeter) on pin 3 of the IC, is fluctuating. When I measure it with an anaerogical meter it fluctuates between zero and 100 mV dc (fluctuation frequency is about 0.5 Hz / s)
I measured the voltage on pin 4 (Vdd) with an analog voltmeter, and I observed that it fluctuates between 7 and 12 Vdc, with an approximate frequency of 0.5 Hz / s
Greetings to all