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

door ejrietbergen , Schiermonnikoog, 21.10.2022, 07:44 (556 dagen geleden) @ tdperez

Hi Taciano

The funny thing is that between the junction R11/C30 and the junction R18/R21 there is a resistance of 7.26k. I don't know where that comes from, and I suspect it comes from SK4.

The 7k26 you’re measuring between the junction of R18/R21 might just be R21 being a bit (7%) high: on FM the junction of R11/C30 is connected to chassis ground via contacts 5/20 and 21 of SK4. So no malfunction there. Since the resistance you’re measuring is higher then the expected value and consistent there are no unintentional parallel contacts made wich would result in a lower value.

As for the reason why the magic eye is not working on FM I’m still puzzling.

kind regards, EJ

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Dingen moeilijk maken is makkelijk, dingen makkelijk maken is daarentegen moeilijk.