Turbo Express Potentiometers Adjustment

[crazedbinary]

Hi All,

Can someone give the proper directions for adjusting the VR500 and VR501 potentiometers?  I have an Express that will not work after cap replacement (I have done a few of these) and need the exact procedure.  I think there is a voltage issue on this board and it may have also blown the screen.  The screen tested fine on another working unit (my personal Express) and now does not work at all even when connecting to the known good Express.  Not a good day for retro repairs.

Questions:

1.) I have searched the forums and know that for VR500 I need to find the -24 volt reading by measuring the CC50 22uF 35v cap.  Do I just measure this from the cap black to positive red to negative and adjust the VR500 potentiometer until -24?
2.) For VR501 (4.5 volt) do I get the reading from CC502 4.7uF 50v?  What voltage should this be reading?
3.) Can I use batteries for this test or does it need to be the OEM plug?
4.) Does anyone on the forums sale used OEM screens?  Are their procedures at to attempt to repair a screen documented?  I definitely have a screen issue here as well after the recap.  It must blown something on the screen as the backlight still works. But no picture even on the known good unit.
5.) Can anyone with a broken or old board for parts sell me a L105 inductor from their old unit?  Mine broke in my personal Express and need to find a replacement.  This inductor is at L105 and is right by the headphone jack.

Thanks guys - CrazedBinary

[crazedbinary]

VR500 on this unit is measuring -14V and not the normal -24V from C502.  This is with the screen plugged in.  Voltage of VR501 seems to be adjusted fine as caps are reading 4.82V

Obviously something is wrong with the VR500 measurement.  I cant seem to get it to change or adjust with adjustments to the VR500 potentiometer.  I did these measurements with the OEM power adapter.