Hitachi LE55A6R9A confirm bad LEDs

[jason424]

I was just given this set, I've looked at many posts and videos that point towards the leds going bad on this set. I've tested the boards and the leads going to the leds and get high voltage at them (287 at red/black lines in pic attached). According to this post sounds like that means an open circuit and the leds should be tested?

[dskall]

Re: Hitachi LE55A6R9A confirm bad LEDs

My experience so far is bad leds. If they flash when you first turn it on I pull the panel and inevitably failed leds.

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

I don't get a flash at all when turning the set on. Just red to blue power led changing.
Also, is there a specific brand of led tester to look for? Price point?

[dick_barton]

Re: Hitachi LE55A6R9A confirm bad LEDs

Have you disconnected the main board and then powered up to see if the backlights come on.
Do you have a photo of your circuit boards?

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

If I disconnect the main board I got nothing. No power led or anything since it looks like it's integrated into the main. Pics attached.

[dick_barton]

Re: Hitachi LE55A6R9A confirm bad LEDs

Behind CN201 you have legends along side the pins. What voltages do you have on each pin.

Pin number.......Pin Name...... Pin voltage
etc

[dskall]

Re: Hitachi LE55A6R9A confirm bad LEDs

Need voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.



Here's tester led tester I have. http://www.ebay.com/itm/NEW-110V-265...item3ad03eb6c6

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

CN201:
12v: 12.2
12v: 12.2
12v: 12.2
GND: 0
GND: 0
GND: 0
GND: 0
BK/ON: 3.2
ADJ: 3.1
PS/ON: 3.2

EDIT: Pic attached of desc/table

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

CN202:
268
187

CN203:
187
0.00

When testing CN202(red) and CN203(black) I get 287 as outlined in the first post.

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

con901:

gnd: 0
key0: 3.3
key1: 3.3
led-g: 3.0
led-r: .1
ir-in: 5.2
gnd: 0
5v: 5.2

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

con701:

l+: .2
l-: .2
r-: .2
r+: .2

[Andrew F. Ali]

Re: Hitachi LE55A6R9A confirm bad LEDs

Confirmed....Bad LED backlights.

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

Thank you everyone for your help/confirmation.

Looks like ShopJimmy is out of the replacements at the moment so I will wait until they're back in stock. In the mean time I will order the tester.

Is is best to just replace all the led strips instead of just isolating those that are bad and just replace those?

[dskall]

Re: Hitachi LE55A6R9A confirm bad LEDs

Preference I guess I just replace bad leds. Shopjimmy is selling used strips. Thier like bad caps now they all going to fail

[Shane711]

Re: Hitachi LE55A6R9A confirm bad LEDs

I got this TV, I am just going to heat the bad LEDs off the strip and heat replacement LEDs from another TV onto the strip. Why buy a strip when I have lots of these LEDs laying around. A heat gun works great for changing them out, a soldering iron will NOT work.

[jason424]

Re: Hitachi LE55A6R9A confirm bad LEDs

I got this TV, I am just going to heat the bad LEDs off the strip and heat replacement LEDs from another TV onto the strip. Why buy a strip when I have lots of these LEDs laying around. A heat gun works great for changing them out, a soldering iron will NOT work.

I ordered the tester and found that all but 1 were out on a strip so I replaced the whole strip and removed the one that was still good and threw it in my parts pile