544 - the auto off dosen't work

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Berichten: 3
Lid geworden op: 22 apr 2019, 23:47

23 apr 2019, 00:08

Hi, this is my first post.

I have a problem with my one 544 box. Even when there is no signal and the automatic switch is turned on, the box is still workig. It sometimes turns off for about 10 seconds and than turns on again.

Does anybody knows what to do? This is the last thing in my 544 boxes thats need to be done.

Im waiting for your response.

Greetings from Poland,
Filip Kupper 🙂
Site Admin
Berichten: 11843
Lid geworden op: 16 jun 2005, 14:55
Locatie: Lochem, Gelderland

24 apr 2019, 09:10

Does the box also make a scratching or rattling sound? Sometimes the FET BF245 on the small input PCB can cause this problem. It generates phantom signals that trigger the automatic circuit.
Thomas Baur
webmaster http://www.mfbfreaks.com
De Enige Echte Philips Motional Feedback Website!
Berichten: 3
Lid geworden op: 22 apr 2019, 23:47

24 apr 2019, 18:15

No sounds.
It only stays ON.
Berichten: 3686
Lid geworden op: 24 aug 2010, 13:29
Locatie: Waalwijk

26 apr 2019, 19:04

As Thomas already said: Most likely the FET TS447 will cause this problem. You can easy check this by removing C578.
If the box not switches on in that case, you have to replace TS447.

Good luck!
Bronnen: GA202, 2X GA212, GA222, AF877, CD202, CD911, 22RH621, 22RH651, TK610, TU 3900, TX-400, N4504.
Versterkers/Receivers: 2X NL312H, 22RH521, 22RH551, 22AH762.
Weergevers: ADK2525, N6320, 2X N6330, MFB: 2X 541, 532, 544, 586, 587
Berichten: 128
Lid geworden op: 30 aug 2018, 19:06

26 apr 2019, 20:38

Sounds like a TS477 problem. You can try replacing the 4,7 uf capacitors on the input board (You can test them first if you have a multimeter that supports it).
Oud naar nieuw :D
Berichten: 3
Lid geworden op: 22 apr 2019, 23:47

28 apr 2019, 08:14

The problem solved!
I replaced TS447 , TS449 and TS452.
Im not a master of using the multimeter so i replaced this 3 parts . I found a post where someone had the same problem and replacing only the TS447 didn't heleped so I've decided to replace the parts he mentioned :)

Btw. the all capacitors were new.

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