Re: need help -samsung 32LE5500 power supply not working
Hi to all, I'm sorry but was unable to join group in mean time, so here I am again.
I still have problem to fix this board. I change PC817 in feed back line from secondary coil but still there is 3.0 - 3.3 VDC fluctuate, VDD on viper 27 going from 10-18VDC with pause of about 2 second. transformer driving signal looks ok.
Any suggestions?
Thanks
microicri
Member
Last Activity: 08-28-2022, 08:50 AM
Joined: 10-20-2017
Location: Rijeka
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Re: need help -samsung 32LE5500 power supply not working
transformer drive on pin 7,8, after I put 22V zener on pin 2...Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
ZD507 on board is 6.8V, and it is changed before I got board. is that proper value? Viper27 start but not continue to work after first wakeing up.Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
I see that I miss value some of diodes on drawing, and ZD 503 is wrongly positioned on drawing. Will change it tomorrow and send again, maybe it will help to someone else with same power supply as there is no schematic available online, or I can not find!Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
Thanks R_J, picture of bottom side is little bit dimly, so I can not see properly, but I will appreciate if you can check for ZD503,ZD507,ZD501 types....Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
Thanks for help,
I search little bit deeper and found one of ZD short(10 OHM). It is ZD503, not sure in value? near IC503
I test circuit with scope, and STBY voltage fluctuate from 3.0 to 3.3VDC and there is no any voltage on ZD503, so VIPER27 go from start to stop and again to start in cycle, but without feed back signal can not continue to work. Also I notice that voltage on pin2 of viper 27 going up and down, so I'm not sure what value of ZD507 should be? According to viper27 data sheet looks...Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
Thanks, will reply to you tomorrow.Leave a comment:
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Re: need help -samsung 32LE5500 power supply not working
Hi there,
here are 3 different pictures of missing elements positions on board.
Thanks for any help....Leave a comment:
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need help -samsung 32LE5500 power supply not working
Hi to all,
power supply received without few elements,FET, transistor and SMD resistor ( someone try to repair it before).
looking for documentation or possible someone can give me a values of mising elements.
I imediately change viper 27 just to start with something. all capacitors are changed by me too. all diodes tested by meter. all fuses tested too, all ok
at the begining problem was stop working because of night lighting and tv stby stop work. the guy open it before me was just a 15 years old school boy, and he lost elements he remove, but also... -
Re: New Members - please post your introductions here
Hi to all,
53 years old electronic eng. Start to work as IT engineer back in 1984 on Sperry 1170. TV repair shop owner at 1986, and so on. Work as service engineer with marine electronics, Computer repair shop owner 1990,marine electronic engineer on board vessels and oil rigs for about 10 years. working within samsung shipyard on series of driling dp rig as E&I engineer. develop DSP recorder for land oil rig + microcontroller software and PC software for same product. Siemens S7 engineer developing control units...Leave a comment:
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