I measured the voltages of my board and I noticed that instead of fixed +15V I have a floating voltages from +12,7V to +13,8V.
I tested my charge pump and it gave me +20,7V! I cannot believe it, yesterday it gave me +18,4V! I did another board (just a couple of components) and the new charge pump gives me +20,7V too! Honestly I don't know what to think... Tomorrow I'll try changing tha 15V regulator on the main board. It's really strange to see this floating voltage (I don't find out any other ways to call it) on my dmm. I don't think the regulator will be the issue. since the 7815 it's very sturdy. If you have any hypothesis, please tell me.