Originally Posted by cellarnoise
I bought a dead FP14000 that was power cycling. After about 50 hours of playing with it and having a friend with a scope check it out the following post solved this particular problem for my amp. Has been working well for several months.
buy one of these:
check out post #3488
. I went with a single turn trimmer as it fit the spot correctly. There is not much room around the CAPs to fit a multi-turn variable resistor. The solder joints on these amps is not always the best....
I dialed the single turn variable resistor to 2500 ohm total resistance. Worked great after that. Also check the other resistors in the general area for proper soldering to the board.
Attached is a graphic showing the variable resistor installation location:
Great thanks so much for the info!
I have emailed Johnson and he has replied with the following:
"please add one 510 ohms or 1K ohms series resistor as attached picture, till the output voltage is approx 150V DC, then solve this problem"
With the same picture that you included in your post. However in the blue circle is says to place either 1k resistor or 510, which was confusing to me. So I asked for further clarification as to which type of resistor I should use and he replied with the following:
"You could purchase ten pieces 510 ohms series resistor and ten pieces 1 K ohms series resistors together, which is very cheap. Then try to add as attached, and till the output voltage is approx 150V."
Which confuses me even further =/
Does he mean to continue adding them across the solder points in the blue circle? Or to add them along the points marked in red?
If it is just to add them across the blue circle then I will use a single turn trimmer as you have described if that is the case.
Also did you test the output voltage was approx 150V after you installed the resistor set to 2.5k? Or did it just work so you left it alone?
Thanks again =)