Hitachi LE55A6R9 LED Issue or?

[LITEZONER]

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.

[attainteddragon]

Re: Hitachi LE55A6R9 LED Issue or?

sounds like bad led's. time to open it up and check them.

[dskall]

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?

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

thank you, I will pull the board and get a picture of the back, from what I have been reading these sets have a high failure rate on the strings.

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

here are some pictures of the back of the board. thanks again, really appreciate all the help.

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

anyone know of another place to buy LED strips besides shop jimmy?

[dskall]

Re: Hitachi LE55A6R9 LED Issue or?

Ebay

[LITEZONER]

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??? LOL

[dick_barton]

Re: Hitachi LE55A6R9 LED Issue or?

If you remove it will they come on. What number is on the chip?

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

A7

[dick_barton]

Re: Hitachi LE55A6R9 LED Issue or?

A7

Looks as though its a diode.
Can't be sure but
http://www.ebay.com/itm/100pcs-1N400...IAAOSwyQtVwjzF

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

whats the point of this diode, surge protection? I just can't see why an LED strip would need this? and Thank you Mr. Barton.

[petehall347]

Re: Hitachi LE55A6R9 LED Issue or?


http://www.electronics-tutorials.ws/...-circuits.html

[budm]

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?

[attainteddragon]

Re: Hitachi LE55A6R9 LED Issue or?

if there is one on each strip, have you tested them, and how many have failed?

[LITEZONER]

Re: Hitachi LE55A6R9 LED Issue or?

all of them have failed, post #13 looks exact except for no Resistor R1

[dick_barton]

Re: Hitachi LE55A6R9 LED Issue or?

Are you saying that none of the led strips light up when testing with your led tester or just one of the strips. Is there an A7 device on all the strips.

[dskall]

Re: Hitachi LE55A6R9 LED Issue or?

Have you tested diode to see if it is shorted. All strips are not bad. You to test at different points to find problem

[LITEZONER]

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.

[budm]

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?