for the hell of it, i disconnected the amplifier board completely from the
circuit, all plugs, and unsoldered the entire board.


the ramp pulse with ringing is still present on the power supply.

but now, when i scope U1001, when i press power, my pulse is showing up now.
it wasnt before. wtf...



"Mike" wrote in message
...
im assuming the "ringing" is the power supply turning on to charge up the
caps to get the voltage back to what it shoudl be, and the steady decline
is the caps discharging, then hits the threshold, and supply starts again.



"Mike" wrote in message
...
Got this set, it would turn on and fire HV for a second, then shut back
down. it wont do it anymore, only did it one time.


I monitored C4118 while pressing the button, it would start off at 13.1
volts, and drop down to about 5 volts. when power button was pressed.


I then replaced CR4118, and replaced 2 caps in the IC chip of the power
supply. the main B+ at standby levels is about 143vdc. the 15v standby is
about 13.3 still.


but this time, when you press the power button, OR perform the manual
power-on, bypassing the micro unit, the voltage doesnt drop anymore, but
the set still is dead. HOT is fine, chopper is running. I dont know what
to look for next.

however if i hold the board in manual power on, every once in awhile the
degauss relay would start clicking on and off a little bit, very faintly,
like a weak supply somewhere.

any ideas?