phillips 40pfl3505d/f7 lcd keeps blowing fuse on power board right by ac input. any idea why?
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Re: phillips lcd keeps blowing fuse
Have you checked any/all of the diodes on your power supply? Mosfets too. -
Re: phillips lcd keeps blowing fuse
I agree. There are usually just about four components that will cause this and one is a very common failure - the bridge rectifier. As Mr. Bill says too, the mosfets are another cause of this problem as well.
With the power disconnected, measure resistance from both fuse tabs to chassis ground.The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS
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Re: phillips lcd keeps blowing fuse
is that something that can be done with a multimeter and no power to the board?Comment
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Re: phillips lcd keeps blowing fuse
Yes.Do NOT touch heatsinks when testing for voltages as they may be LIVE!Comment
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Re: phillips lcd keeps blowing fuse
put the multimeter in the "Ohm" section and measure the 4 diodes one by one, or if your psu has a big bridge rectifier measure the 4 pins, alternating the probes. if you get 0 Ohms that means a diode (or more) is shorted.Comment
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Re: phillips lcd keeps blowing fuse
about the only way i can get a reading is to set meter to 20m or 20k is that correct?.. here are some pictures of the power board im not 100% . sure what a bridge rectifier is but i think i have it circled alone with a diode and something else im not sure what its called . ..sorry im still learningAttached FilesComment
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Re: phillips lcd keeps blowing fuse
Set the meter to the range which looks a bit like this ->|-
If that highlighted diode reads zero in both directions it could be the fault. On these power supplies (resonant self-oscillating, no intelligent control) a shorted output will blow the fuse.
This is a bridge rectifier, typical appearance on a power supply:
http://media2.rsdelivers.catalogueso...7005465-10.jpgPlease do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: phillips lcd keeps blowing fuse
I noticed that >| thought i had it set wrong.. theres alot of diodes to test..wil do that after dinnner! when you say " reads zero in both directions " are you talking about taking a reading then switching probe ends around ie.+ - then -+...thanksComment
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Re: phillips lcd keeps blowing fuse
Yes... and by zero, I should say, anything less than about 100 is most likely shorted, but almost every diode I have had fail does so at dead zero (or a few millivolts) in both directions.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: phillips lcd keeps blowing fuse
well if I was testing correctly there's about 60 bad diodes! some were good but 95 percent were bad
I had the multimeter set on 200... best just to buy a new board?Comment
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Re: phillips lcd keeps blowing fuse
What brand is your multimeter, or post a picture of it. I'm thinking your doing something wrong. The meter needs to be set to diode mode. You should get a reading and when you reverse the probes you should get OL.Comment
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Re: phillips lcd keeps blowing fuse
the meter is a Etek. the pictures show the settings and how i test.Attached FilesComment
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Re: phillips lcd keeps blowing fuse
what your testing in pic no 2 is a resistor not diode. turn your metre one more clockwise.
that is the diode mode.Comment
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Re: phillips lcd keeps blowing fuse
I know thats was not a diode..i was just trying to show the way i test. i was hoping i had done something wrong! lol ok i will retest again with the right setting. thanksComment
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Re: phillips lcd keeps blowing fuse
ok just noticed im getting a beeb from the meter when testing some diodes???Comment
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Re: phillips lcd keeps blowing fuse
what is the meter displaying when it beeps?Comment
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Re: phillips lcd keeps blowing fuse
its good if you get beep only one way.Comment
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Re: phillips lcd keeps blowing fuse
got a beep both ways on one diode. it displays 0.24 on meter when it beeps. seems to be about 4 bad diodes.. read about 5 to 6 then when i change ends with the probe I get 1... i think thats 0 How do i identify the diodes so i can buy the correct ones?Comment
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Re: phillips lcd keeps blowing fuse
Are you testing them still on the board or lift one leg off the board? To be accurate, you should at least lift one leg off the board and measure them again.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Good day folks......wow this new layout is weird. It's like I woke up one day and I'm no longer on Planet Earth or something
Anyway....got this here power brick from a USB to SATA adapter which keeps blowing the fuse after I almost repaired it. The reason I even bother to fix a power brick (wall wart, whatever) in the first place is because this thing was really convenient to use: I'd just plug it and that's it. It's a dual output supply, for both 12v and 5v, which although I COULD easily obtain with a DC-DC converter from a standard 12v adapter, I thought I should crack open the... -
Looking for some assistance please.
Trying to repair a PD27AOQ samsung power board.
Initially had the typical problem of cm806 capacitor blown, additionally thermistor NT801s blown.
Replaced the ceramic capacitor, str60252s, bridge rectifier, thermistor and fuse.
Testing it the fuse blows immediately power is turned on.
diodes dm852 and dm853 test as shorted when in the board but fine when removed.
any assistance, guidance would be appreciated. -
Hi all,
I am a newbie and not very experienced so bear with me if i struggle sometimes with technical language - but I'll do my best. I searched "Samsung" and the model number on the forum but didn't find anything I could understand!
I'm not an electronics guy - just picked up stuff over the years through my flight-simming hobby.
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There is « O » mark beside. All fuses have the same mark letter on main board. So, I can deduce it's a « O » fuse.
And this correspond to the issus I saw : when I plug the battery, I measure the voltage dropping... -
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