Отправлено: 11.06.08 14:18. Заголовок: ­Differences

Hi friends !

I am studying the circuit.
I found some differences between schematic and the printed circuit board made from Andron.

I found that R40 and R42 value are 270Kohm reading the pcb but 100Kohm and 100ohm reading the schematic.

Continuing to read the pcb I found that U3-3 is free and U3-4 is used together to R36, R39, R43, C28 and C29.
The output of apamp is connected to K18; all these are missing in the schematic.
Which is the use of K18 ?
Peraphs, it is a test probe for oscilloscope.

Bye,
Marco­