Re: atec 37 inch lcd psu faulty?
its even crusted the breadboard away i think its gone to heaven. oh well on to the next thanks for the help tho :-)
clean-machines
Member
Last Activity: 07-11-2012, 04:29 PM
Joined: 07-05-2012
Location: southampton
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Re: atec 37 inch lcd psu faulty?
oh damn i left the workshop monday night and did the un imaginable... i left the soldering iron on it slipped onto the board and spent 19 hours slowly burning the ps melted loads of little sm components its runined ! not happy at all!Leave a comment:
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Re: atec 37 inch lcd psu faulty?
thanks bud m well so far iv re worked the board (all the solder sm and thru hole also esr all the caps i had two that were not getting s reading due to being in circuit took them out and they teste fine
well bud m as we dont seem to be able to find the datasheet on this (i cant ) im not sure on pin outs but i did find potential of 5 volts and 8 volts accross the chip
this is when in standby and booster is off
when however the ps attempts to power up / boot , those potential differences i have accross...Leave a comment:
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Re: Vizio VW42L -No Power/Fuse keeps blowing
if the meter beeps at you a lot on one or more of the parts your probing or you get a verylow voltage drop across the components then that point toward the failed component un solder it from the board and check again if its still shorted then you know its that, once youve found the shorted part if its the bridge just change it and your fixed if its the transistor then trace the driver by tracing the track from the gate pin of the shorted transistor and again check the driver to the transistor it may be a small ic or a small sm transistor...Leave a comment:
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Re: Vizio VW42L -No Power/Fuse keeps blowing
there is the bridge rectifier right next to the big cap on its side go past the 4 blue bits and its the large flat black thing on the heat sink it has 4 pins going down to the board thats the bit toms on about check it for shorts like tom said the drive transistors are the other large black squares on the heat sinks with 3 legs set meter to diode and test to see if theyve shorted that will be a good startLeave a comment:
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Re: atec 37 inch lcd psu faulty?
budm
as the ps on goes high there is no change on the dc filter cap its 327v
and goes up (twitchy) to 328v when ps on is activated something is happening tho as you can hear it the tone changes
also tried tricking the opto isolators to switch it on and does the same thing so im sure it is TRYING to turn on when ps on is recieved by the ps?
i think the ic 2 is a current mode power factor control so il have to re test that but i think its not a problem it should still work if this is faulty right as all it does...Leave a comment:
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Re: atec 37 inch lcd psu faulty?
well when ps is fully plugged into main board if i probe 5v stanby i get 5 v to the main board an orange standby light and 1.48v on pson however if i remove the ps on cable i get 5v from mainboard but budm explained this to me its a normal voltaged drop
tom should i be able to power up the psu on its own using ps on? iv tried and i get nothing from any outputsLeave a comment:
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Re: atec 37 inch lcd psu faulty?
thanks guys il make sure they are no more than 2000x2000or under
quick update had a quick look last night dont have my scope at the mo just a multimeter ! just had the psu board on the kitchen table after making a bit of toast mmm,
powered it up and gave it a small pulse on the ps on tab to try switch it on, i heard a change in note of the buzzing , got slightly slower ,
it looks like the ic12 fairchild green current mode pwm controller is pulsing ok for the standby transformer,
however the chip on top left...Leave a comment:
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Re: atec 37 inch lcd psu faulty?
okey dokey this is honestly the first time iv ever up loaded a picture onto a hosting web site
somebody better slap me into the year 2012 !
il report back on monday evening thanks again for your helpLeave a comment:
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Re: atec 37 inch lcd psu faulty?
my uncle said the board was repaired 1 year ago and failed again after 1 year so he brught a new tv
so on posting pics i posted these 9 megapixels on a site , how are you putting them as thumbnails onto the thread?
never been on a thread before sorry guys , i assume they will be better quality as the hosting site has resized them even tho i told them not to ?
iv also done some soler re work myself on dry looking joints and i put the jumper in looks like the repair guy last time did the easy bit (replaced bad caps and...Last edited by clean-machines; 07-06-2012, 02:54 PM.Leave a comment:
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Re: atec 37 inch lcd psu faulty?
thanks budm and tom , clearly i need to go back to school!
il check that is actually recieveing the signal by checking the dc filter cap
also tom i cant find a 5v cap could you point me in the direction, i esr`d most of the caps but il esr all of them on monday and get back , cheersLeave a comment:
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Re: atec 37 inch lcd psu faulty?
here we go then heres some piccys
[URL="http://*************/photo/my-images/232/06072012361.jpg/"]
[URL="http://*************/photo/my-images/689/06072012360.jpg/"][URL="http://*************/photo/my-images/820/06072012359.jpg/"]
ics are 7601 628 , top middle of pic , loc ic12
13002L 604 top left of pic , LOC IC2
290g12 bottom right of pic loc , ic4
ok so the 7601 is a fairchild fan7601 green currentmode pulse width modulation contoller
...Leave a comment:
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Re: atec 37 inch lcd psu faulty?
hi tom i will do that as soon as i read your post its the same excat board as far as i can see il try upload them tomoro if i can work out how lolLeave a comment:
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Re: atec 37 inch lcd psu faulty?
pwm controller anyone got a manual for this ? how does the 5 volts from the main board switch on the psu on this one? im not with the psu right now but i will take a look later on , cheers any help apreciatedLeave a comment:
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atec 37 inch lcd psu faulty?
i love getting into component level i got this tv the other day it shows an orange light upon putting ac mains into the psu,
the standby 5 volts is there and sends out to the main board but im only getting 1.44 volts back from the mainboard to turn on the psu.
thought it must be being dragged down and sure enough if you remove the 5 volt logic between main board and psu the psu on signal from main board is a steady 4.98 volts ? this is pointing me toward the psu faulty
also its making a funny quiet squealing noise sounds about 13khz (maybe well off) but its... -
Re: New Members - please post your introductions here
1Last edited by clean-machines; 07-05-2012, 08:44 AM. Reason: didnt realise i could edit posts sorry learningLeave a comment:
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Re: New Members - please post your introductions here
hi im jason from southampton
iv been looking for a while so thought i might aswell join
first off there are a few legends in here firstof all big up to tomm66 your a ledg mate you never giv up til you find whats wrong and tomcat my mate has a nissan fairlady 300zx twin turbo and its got the sexiest curves of any car iv ever seen iv always wanted one (jealous)
iv been a tech for 10 years on refigeration mechanics and electronics done quite a lot in the past few years to component level and i love it no...Leave a comment:
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