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Old 08-01-2019, 09:22 AM   #12
R_J
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Join Date: Jun 2012
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Default Re: Philips 234e problem

Q492 is a AO4411 fet. I would think the +5volt line should supply a at least 1 amp and likely more like 2~3 amps
If there was corrosion on Q492, I suspect there is corrosion elsewhere and maybe a corroded trace or feedthru.

What does'nt make sense about the U705 circuit? Pin 5 (LX) is the output which connects to a coil and then to Q492 fet, Q492 is likely a switch that turns off part of the circuit during standby.
What about the input voltage to U705, does it com straight from the 19v input? Check the resistors around the ic, maybe they are corroded as well and changed value
Attached Files
File Type: pdf AO4411.pdf (608.9 KB, 5 views)

Last edited by R_J; 08-01-2019 at 09:53 AM..
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