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

door ejrietbergen , Schiermonnikoog, 19.10.2022, 23:53 (765 dagen geleden) @ tdperez

Hi Taciano

that’s a very clear explanation of your problem.

Since you’ve tried everything else only SK4 and the EABC80 remain as suspects.

With the unpowered radio on FM you should have continuity from pin 1 of the EM84 and the point in between R’s 18 and 21 (or 5k8 between EM84 pin 1 and EABC80 pin 7). If not the section 5/6/7 of SK4 is faulty.

If this section of SK4 seems to be working fine, the only other explanation I can think of is a bad contact or a dry solder joint on pins 1,2,3 and/or 7 of the EABC80, or a broken EABC80 that needs replacing.

If you don't have a EABC80 (yet) you could try to temporarilly clip in two solid state diodes like 1N4148 between pins 1 and 7, and between 2 and 3 (kathodes to 3 and 7) and see whether the EM84 works. If it does, replace the EABC80.

Succes! Kind regards, EJ

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