piccy
Member
Last Activity: 05-02-2025, 09:34 AM
Joined: 12-22-2014
Location: kerry
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HP G7BF motherboard schematic please
liquid damage , not charging or powering on -
42LG500 stuck in standby then after being disconnected for a while works again
have a LG 42LG500 tv that went into standby a couple of days ago and just blinks 3 times bright red led when attempting to switch it on , have not used it for a couple of days and it was disconnected from mains supply it now switches on again , is this an eprom issue that i know some lg 's suffer from or an invertor board fault. The power supply seems ok voltage wise i will re check the invertor 24vLast edited by piccy; 03-03-2016, 02:43 PM. -
Re: fsp223-3f01 power supply
so at 320v its not far away , not sure where to progress now any suggestions please budm,
have spotted a psu for sale in uk i may order it , i will then use that to find fault area on the original supply , bit of a cheating way wanted to get to the bottom of this the proper way -
Re: fsp223-3f01 power supply
just resoldered a few connections on the board main filter cap voltage is now up to 320v and the buzzing is all the time ( normal operation type buzz ?)Leave a comment:
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Re: fsp223-3f01 power supply
just resoldered a few connections on the board and there is now a intermittent faint buzz coming from the board - seems to do it for a short time then stops have warmed it with a gentle heat source seems to make no differenceLeave a comment:
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Re: fsp223-3f01 power supply
thanks for that will check it
pins are marked different schematic i have
pin1 FB
pin2 comp
pin3 mult
pin4 cs
pin5 zcd
pin6 gnd
pin7 drv
pin 8 vcc
will compare the two , have just found a schematic for fsp115-3f02 that uses a fan 7930will compare the circuits
are there any other tests i can make round the chip that will show if it is working ?Leave a comment:
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Re: fsp223-3f01 power supply
yes two diodes tested ok
part number i can see on chip is 1606B (the b may be an 8 difficult to make outLeave a comment:
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Re: fsp223-3f01 power supply
not main cap fitted one and it goes up by a volt interestingly for a brief few seconds it very quietly made buzzing (normal running type of noise) so think a poss break in a track or dry joints though no obvious ones so will have a little resoldering sessionLeave a comment:
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Re: fsp223-3f01 power supply
what value would you expect r621 (bottom leg of Q601 i measured it at 0.5 ohm ? high wattage
could i have a bad main filter cap even though it measures ok on an esr meterLast edited by piccy; 05-20-2015, 11:10 AM.Leave a comment:
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Re: fsp223-3f01 power supply
tested them they read ok with peak dca semiconductor tester (one leg out of circuit)
can i test for a voltage on there or is it now high frequency (dont fancy putting my scope in there )
cant see any shorts on q601 , d603 or q601 eitherLast edited by piccy; 05-20-2015, 10:41 AM.Leave a comment:
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Re: fsp223-3f01 power supply
Hi Budm
have measured voltage on u601 across pins 6 and 8 and i get 15.1v , i have connected the main board feed and it still reads 15.1v so i can presume the feed from the main board is sufficient to operate it , if i put the set in standby then the 15.1v disapears as you would expect.
just done a few checks round the pc501 opto on pin 1 i get 5.24v on stby and when remote pressed this drops to 1.4v suggesting to me that the transistor is being switched on
as a follow on presuming from that the opto is working as...Leave a comment:
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Re: fsp223-3f01 power supply
sorry, had to nip out will check it in the morningLeave a comment:
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Re: fsp223-3f01 power supply
think i will solder wires to the pins and get them away from the board , dont like nasty voltages, what should i expect vcc to be 5v ?Leave a comment:
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Re: fsp223-3f01 power supply
looking at the drawing most of which i need to figure out and is going to have me scratching my head but am i right in thinking pfc controller ic is U601 ?Leave a comment:
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Re: fsp223-3f01 power supply
ignore most of the last post couldnt see the pdf attachment for some reasonLeave a comment:
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Re: fsp223-3f01 power supply
ok,
have you access to the schematic ? the link i followed doesnt show anything different to the one you posted (no drawing) , will also have a read of the links you posted to articles have read the basic troubleshooting one , will look at the regulator infoLeave a comment:
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Re: fsp223-3f01 power supply
Hi Budm,
tried putting resistor across from 5v rail ,this put 3v onto stby pin voltage across main filter cap 317v before linking with resistor no increase after putting link in place so not sure where to go from here i will check the components in the circuit that the standby wire comes into theres a resistor diode and cap in there along with some optos
any suggestions welcomeLeave a comment:
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Re: fsp223-3f01 power supply
will try that later today , thank you will let you know the outcomeLeave a comment:
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Re: fsp223-3f01 power supply
Just split the stby wire from the main board to the psu , with it disconnected from the psu i get 2.36v if i connect the wire to the psu it falls to 1.71v
deducting from that i guess the fault is on the psu side (unless the stby voltage should be higher than 2.36v )
removing the 24v connector makes no difference, removing the 12 connections may be more difficult
can i somehow put 3v onto the stby pin from say the 5v supply ?
just tried opening the pdf you posted there is just a link to a website...Last edited by piccy; 05-19-2015, 09:28 AM.Leave a comment:
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Re: fsp223-3f01 power supply
Hi ,
thanks for pdf
pictures of board attached , i know the connector doesnt look sat in socket properly but i removed it and didnt put it back fully for photo
all tests were made with the connector in fully.
i was thinking of disconnecting the stby pin wire to measure the voltage on it then and see what it reads
is the voltage on the stby (ps_on) pin generated from the main board ?...Leave a comment:
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