DHD AMP -NTX 3107 parts info

[Hexhclass]

hi all

Am trying to find out the vlaue of a resistor (RP18).It is connected to the first leg of A1220A-y transistor(QP5) and the center leg of c2316 transistor(QP3) This is in the power supply.THis amp came in with capacitor (c2) and resistor RP18 burnt.

 

[Perry Babin]

If one end connects to the B+ terminal of the amp and the collector of the 1220 connects to pin 11/12 of the 494, it's likely 4.7 ohms.

 

[Hexhclass]

I put in a 4.7 resistor and i replace the cap.Amp power up and plays good audio.The power supply FET (FQP50n06) have 0.5v on the gate leg,is that normal? Isn't it suposed to be about 4.*v?

 

[Perry Babin]

If the supply is regulated, the voltage at the gates may be very low. As long as the rail voltage is correct and the voltage on pins 9/10 and the gates is close, it's likely OK.

 

[Hexhclass]

I run it at full power and it is working good

Thanks for the help