I have been doing some testing and a lot of reading and began to tackle U2126 first. On pin 12 the waveform is shown as roughly -6 volts and this is wrong on mine.
It varies with the display brightness control and will not budge above -0.5 volts. Pin 11 where the signal from the brightness pot connects also will not budge above -0.5 volts unless I power up with U2126 removed. This allows it to go from +4.5 volts for minimum brightness to -13.5 volts at maximum brightness on pin 11.
With U2126 in place disconnecting the Z amp cable does not restore it.
CR2124 and CR2125 have been tested as have R2122 and R2123.
Pin 12 has narrow positive going pulses and these are present also on pin 11 but these are narrow enough that a DVM ignores them and also they only come up to 0 volts.
The pulses vary with the settings on the plugins so that part is working.
Has anyone got a U2126 I could borrow?
The part No is 155-0021-01
Readings from pins 11 and 12 for maximum and minimum brightness would be useful if you have got the cover off..
It varies with the display brightness control and will not budge above -0.5 volts. Pin 11 where the signal from the brightness pot connects also will not budge above -0.5 volts unless I power up with U2126 removed. This allows it to go from +4.5 volts for minimum brightness to -13.5 volts at maximum brightness on pin 11.
With U2126 in place disconnecting the Z amp cable does not restore it.
CR2124 and CR2125 have been tested as have R2122 and R2123.
Pin 12 has narrow positive going pulses and these are present also on pin 11 but these are narrow enough that a DVM ignores them and also they only come up to 0 volts.
The pulses vary with the settings on the plugins so that part is working.
Has anyone got a U2126 I could borrow?
The part No is 155-0021-01
Readings from pins 11 and 12 for maximum and minimum brightness would be useful if you have got the cover off..
