hey ya all, hope all is well with you folks. Hope to ask for some help, this Hitachi set i am working on has no back light but does have an image via the flashlight test. my question is this: there are 66 LED's in this set, 6 rows of 11, at 1.5V each should require 99V to turn them on. well I am getting 186V at the power supply terminals that go the the LED's on one pair and 0V on the other pair, I am thinking the strips LED, are toast and not presenting a load on the power board, but the voltage seems awful high even with no load??? Thanks for your help all.
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Hitachi LE55A6R9 LED Issue or?
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Re: Hitachi LE55A6R9 LED Issue or?
How do you know they are 1.5v? My experience is around 3.2v. Budm and others are the experts so my correct me but seems if each connector is feeding 3 strings then you have bad diode or something on side with 0v. Could we get a picture of back of board?Last edited by dskall; 05-30-2017, 08:47 PM.I assume no responsibility for any stupid suggestions I might post.
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Re: Hitachi LE55A6R9 LED Issue or? HOPE this HELPS Someone
so in testing the LED strips I came across an issue i have not seen before. most may already know but i didn't. after much reading i decided to buy an LED tester (GOLDEN) My strips will not light up HOWEVER all led lamps tested good and do light up individually, Problem seems to be this little fuse of diode not sure exactly what it is but it no longer allows the flow of current to the strips, see Pictures, so i have perfectly good LED's but bad tiny i will call them fuses for now, thought about bridging them, but then came to realize they are what i believe to be protection against power surges possibly, any thoughts from you pros is appreciated, i have read about the high failure rate on these LED strips in Hitachi sets, may not be the LED's at all, just this little fuse? STD DIODE??? LOLLast edited by LITEZONER; 06-08-2017, 11:14 AM.39 Soldering Iron burns And Counting
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Re: Hitachi LE55A6R9 LED Issue or?
Originally posted by LITEZONER View PostA7
Can't be sure but
http://www.ebay.com/itm/100pcs-1N400...IAAOSwyQtVwjzFLast edited by dick_barton; 06-08-2017, 12:54 PM.Willing to help but I'm no expert.
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Re: Hitachi LE55A6R9 LED Issue or?
Protection diode in case wrong power supply polarity is connected to the LED strip?
Is it connected in parallel with the two pin of the connector?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=24809
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Re: Hitachi LE55A6R9 LED Issue or?
there is an A7 on every strip, none of them light all together up but every LED tested good individually. A7 are only on the lead strip where they connect, trailing strips light up fine together.Last edited by LITEZONER; 06-09-2017, 09:52 AM.39 Soldering Iron burns And Counting
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Re: Hitachi LE55A6R9 LED Issue or?
I still do not understand the situation, if you test EACH LED strip by itself (not connected to other strip or the circuit), do each strip light up using the tester?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=24809
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