EM84 magic eye does not close on FM on Philips B4X92A (Techniek Radio/TV)

door tdperez , Eindhoven, 23.10.2022, 15:06 (554 dagen geleden) @ Maurice

Hi Maurice,

Thanks again for the detailed answer. I think I understand now how the switches work, and made a diagram that represents the state when the FM button is pressed (both SK4 and SK5 activated), see below.

Meanwhile, I've unsoldered the connection between R11-C30 and pin 5 of SK4, in order to chase any rogue DC-path, with this outcome:

1. Now there is no continuity between R11-C30 and (R18-R21 or EM84pin1)
2. When I turn the radio on with FM selected, I still have the same result (radio works, but EM84 does not move). Voltage at EM84 pin1 is still around 0.3VDC.

So that seems to rule out that a DC-path from EM84 pin 1 to R11-C30 causes the problem...