I'm trying to fix SSB 25W amplifier, it's worked and I overrated Amplifier with voltage, and step modulator voltage regulator get burned, which is inside with amplifier in Al box.

New voltage regulator
https://www.aliexpress.com/item/100...o.order_list.order_list_main.5.50181802pJay1L

Amplifier is like this one:
https://www.ebay.com/itm/134354468125

I could'n find exactly the same modulator, but close enough with specs, and footprint is little bigger than original, but now amplifier is not working as before.

I try to contact seller, but he didn't help. Inside i on main board another trimmer, whith whom you regulate voltage on mosfet gate, mosfet is this one

https://www.nxp.com/docs/en/data-sheet/MRFE6VS25N.pdf

This is inside amplifier




Can someone help me with tuning amplifier, don't know what I need to do, increase voltage from step voltage modulator, now is around 12V, change voltage on mosfet gate, now is around 3.3 and 3.5 V

 

こんばんは。
あなたの増幅器の修理の投稿を見ました。

最初にレギュレータが燃えた時、もうFETゲートに異常な電圧を加えていませんか？FETのゲート電圧を加えて徐々に増やして、ドレイン電流が流れ始めますか？
流れ始めるならまだFFTは壊れていないでしょう。電流が流れないなら、FETは交換が必要です。

Mod: translate, please use English text.

Good evening.
I saw your amplifier repair post.

When the regulator first burned out, were you already adding an abnormal voltage to the FET gate? Do you gradually increase the gate voltage of the FET so that the drain current starts to flow?
If it starts to flow then the FFT will not be broken yet. If no current flows, the FET needs replacement.

 

こんばんは。

Sorry, this is an English only forum.;

 

Good evening.
I saw your amplifier repair post.

When the regulator first burned out, were you already adding an abnormal voltage to the FET gate? Do you gradually increase the gate voltage of the FET so that the drain current starts to flow?
If it starts to flow then the FFT will not be broken yet. If no current flows, the FET needs replacement.

Mod: translate, please use English text.

Good evening.
I saw your amplifier repair post.

When the regulator first burned out, were you already adding an abnormal voltage to the FET gate? Do you gradually increase the gate voltage of the FET so that the drain current starts to flow?
If it starts to flow then the FFT will not be broken yet. If no current flows, the FET needs replacement.

I have power supply with trimmer on voltage and current, regulator burned out when I increase voltage on power supply for couple of volts, btw readings between power supply LCD screen and unimer showing deviations for 5V in case for unimer (shows more), when I regulate voltage on 50V. I don't know what IC code is on regulator, cause is burned. I try to test resistance on mosfet gate and drain. Google search tells me that readings need to be around mega ohms gate-source and drain-source. I can't measure megohms, more like kiloohms. If anyone can help, how can I test mosfet more, to be sure if it's broken or not .