Hopefully I can save someone some time or maybe they can avoid fixing these garbage epoxied TV sets
.. stripping down was a pain .. tons of screws all along bezel edge .. the top of the glass LCD panel is glued to the casing (for a reason)
.. all in all took around 4-6 hours to repair teardown .. swap .. reassemble .. current adjustment and then burn in and extra evening
.. single blown backlight led top left row .. 3030 5.5v (6v) .. I had some in stock from another set
.. swapping LED no problem .. one bad led .. the solder pad under this LED is normal .. no angles or points or strange keyed shapes etc .. swapped in and it works again
1/31/22 SETTING BACKLIGHT CURRENT
.. chip is OZ9976 .. O2 Micro
-- OZ9976 OZ9919_O2Micro.pdf pg14
.. PDIM is pwm dimming on this chip and gets fed a straight DC voltage ~4v instead of a PWM signal
.. ADIM analog dim did nothing when I started grounding used a 200k pot in series with heavy 100ohm resistor .. PDIM changed the duty cycle of the PWM drivers pin 1 and 16 .. dropped it from 300ma to 120ma using ~77k dropping PDIM to ~1.7v
MY VERDICT
Avoid TCL ROKU repairs if you can .. the epoxy along the top edge is there to keep the glass panel centered exactly in the bezel .. if you do not re-glue it .. it will come off center and the glass press against the edge and crack .. mine cracked on the edge after it was repaired and I had ran it for 2 nights .. even though I am ultra careful with panels what a waste of time
.. stripping down was a pain .. tons of screws all along bezel edge .. the top of the glass LCD panel is glued to the casing (for a reason)
.. all in all took around 4-6 hours to repair teardown .. swap .. reassemble .. current adjustment and then burn in and extra evening
.. single blown backlight led top left row .. 3030 5.5v (6v) .. I had some in stock from another set
.. swapping LED no problem .. one bad led .. the solder pad under this LED is normal .. no angles or points or strange keyed shapes etc .. swapped in and it works again
1/31/22 SETTING BACKLIGHT CURRENT
.. chip is OZ9976 .. O2 Micro
-- OZ9976 OZ9919_O2Micro.pdf pg14
.. PDIM is pwm dimming on this chip and gets fed a straight DC voltage ~4v instead of a PWM signal
.. ADIM analog dim did nothing when I started grounding used a 200k pot in series with heavy 100ohm resistor .. PDIM changed the duty cycle of the PWM drivers pin 1 and 16 .. dropped it from 300ma to 120ma using ~77k dropping PDIM to ~1.7v
MY VERDICT
Avoid TCL ROKU repairs if you can .. the epoxy along the top edge is there to keep the glass panel centered exactly in the bezel .. if you do not re-glue it .. it will come off center and the glass press against the edge and crack .. mine cracked on the edge after it was repaired and I had ran it for 2 nights .. even though I am ultra careful with panels what a waste of time
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