Hi Folks,
I saw a similar post (https://www.badcaps.net/forum/showth...5UH5500&page=3) but it didn't really state the issue, so I'm giving it another shot
Got this TV, and upon firs power up, the backlight flashes on, then off. Classic symptom of Bad backlight LED. Ordered a set and opened it up without making any measurement (cause I was just sure!!!
) and after over 90 screws, all LEDs tested out ok. Repeated the test to make sure - and no question, every single strip tested out fine (I just used a 90V supply with current limit resistor - Home made)
Buttoned it back up and started taking measurements. The LED Driver board shows DRV_ON and PWR_ON and 13.2 V pins (accessible)
Upon first power up, the PWR_ON goes to 3.2 V, then DRV_ON goes momentarily to 3.2 V, backlight comes on, the main board has RED LED that comes on, Optical port LED comes on, then all come off (including PWR_ON and DRV_ON SIGNALS) - That's it. Second turn on attemp using power button takes PWR_ON to 3.2 V, DRV_ON goes to 57 mV then back to 0. PWR_ON goes to 0 then back to 3.2 and stays on no matter how many times I press the Power button. Backlight never comes back on again, unless I hard reset (unplug from wall then reconnect power)
The 13.2 V on the Driver board are 9.25 V, never reach 13.2 V (mislabeled?)
Could it still be backlight like everyone seems to be leaning to?
On the Power Supply Board, there is a Fail pin.. someone said short it and power up.. I did.. and Voila.. it's up and running, beautiful backlight and picture.. What does that mean? how can I clear that "Fail" state so I can power up without this jumper?
I saw a similar post (https://www.badcaps.net/forum/showth...5UH5500&page=3) but it didn't really state the issue, so I'm giving it another shot
Got this TV, and upon firs power up, the backlight flashes on, then off. Classic symptom of Bad backlight LED. Ordered a set and opened it up without making any measurement (cause I was just sure!!!
) and after over 90 screws, all LEDs tested out ok. Repeated the test to make sure - and no question, every single strip tested out fine (I just used a 90V supply with current limit resistor - Home made)Buttoned it back up and started taking measurements. The LED Driver board shows DRV_ON and PWR_ON and 13.2 V pins (accessible)
Upon first power up, the PWR_ON goes to 3.2 V, then DRV_ON goes momentarily to 3.2 V, backlight comes on, the main board has RED LED that comes on, Optical port LED comes on, then all come off (including PWR_ON and DRV_ON SIGNALS) - That's it. Second turn on attemp using power button takes PWR_ON to 3.2 V, DRV_ON goes to 57 mV then back to 0. PWR_ON goes to 0 then back to 3.2 and stays on no matter how many times I press the Power button. Backlight never comes back on again, unless I hard reset (unplug from wall then reconnect power)
The 13.2 V on the Driver board are 9.25 V, never reach 13.2 V (mislabeled?)
Could it still be backlight like everyone seems to be leaning to?
On the Power Supply Board, there is a Fail pin.. someone said short it and power up.. I did.. and Voila.. it's up and running, beautiful backlight and picture.. What does that mean? how can I clear that "Fail" state so I can power up without this jumper?
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