Powers on
Backlight comes on
Plays sound (firestick menu sound through HDMI)
LCD dark grey, no boot logo, no image
I guessed Main board and PSU likely good and focused on T-Con + Panel. No experience debugging T-Con.
T-Con
Disconnecting one of the LCD flex to T-Con doesn't improve anything. Screen remains dark grey but the side with the pulled flex is slightly different shade of grey.
T-Con Voltages
All voltages are stable for about 20s then starts cycling at ~2s intervals. This is with both LCD flex connected, disconnected, or only 1 side disconnected. Seems cycling is not normal.
F1 both side of fuse cycles between 12.03 <-> 12.1
VCC 3.3 <-> 0
VCORE 1.2 <-> 0
HVDD 0.06 <-> 0
VGH 1.38 <-> 0
VGL1 -6.9 <-> 0
V??2 (near D3) -14.8 <-> 0
VCOM1 0.12 <-> 0
VCOM2 0.33 <-> 0
VA1/VA2 (not sure which is which from the label) 0.03 <-> 0 12.08 <-> 12.03
VIN 12.08 <-> 12.02
VST -14.8 <-> 0
VCC1B 1.83 <-> 0
VCOMRFB 0.13 <-> 0
VDD 2.09 <-> 0
V1/V4/V5/V6/V9 2.26 <-> 0
V10/V13/V14/V15/V18 0.16 <-> 0
T-Con does get pretty hot. Hotter than I would have expected but don't know what is norm.
Main Board
P-ON +12V shows 12.1v rock solid
Cap near pin 51 of T-Con connector shows 12.08 <-> 12.10 with T-Con connected. Solid 12.10 without T-Con connected
Testing Setup
T-Con is assembled under the PSU and main board. Mostly covered by PSU. To read the test points, moved T-Con above with paper underneath for insulation and ground jumper to chassis. See last pic.
Questions
- What other test can be done? Don't have logic analyzer for clocks/waveforms
- T-Con failure likely?
- Should I expect white on 1/2 of screen with 1 panel flex disconnected from T-Con? I've seen this behavior before on a Samsung but perhaps its panel dependent?
Backlight comes on
Plays sound (firestick menu sound through HDMI)
LCD dark grey, no boot logo, no image
I guessed Main board and PSU likely good and focused on T-Con + Panel. No experience debugging T-Con.
T-Con
Disconnecting one of the LCD flex to T-Con doesn't improve anything. Screen remains dark grey but the side with the pulled flex is slightly different shade of grey.
T-Con Voltages
All voltages are stable for about 20s then starts cycling at ~2s intervals. This is with both LCD flex connected, disconnected, or only 1 side disconnected. Seems cycling is not normal.
F1 both side of fuse cycles between 12.03 <-> 12.1
VCC 3.3 <-> 0
VCORE 1.2 <-> 0
HVDD 0.06 <-> 0
VGH 1.38 <-> 0
VGL1 -6.9 <-> 0
V??2 (near D3) -14.8 <-> 0
VCOM1 0.12 <-> 0
VCOM2 0.33 <-> 0
VA1/VA2 (not sure which is which from the label) 0.03 <-> 0 12.08 <-> 12.03
VIN 12.08 <-> 12.02
VST -14.8 <-> 0
VCC1B 1.83 <-> 0
VCOMRFB 0.13 <-> 0
VDD 2.09 <-> 0
V1/V4/V5/V6/V9 2.26 <-> 0
V10/V13/V14/V15/V18 0.16 <-> 0
T-Con does get pretty hot. Hotter than I would have expected but don't know what is norm.
Main Board
P-ON +12V shows 12.1v rock solid
Cap near pin 51 of T-Con connector shows 12.08 <-> 12.10 with T-Con connected. Solid 12.10 without T-Con connected
Testing Setup
T-Con is assembled under the PSU and main board. Mostly covered by PSU. To read the test points, moved T-Con above with paper underneath for insulation and ground jumper to chassis. See last pic.
Questions
- What other test can be done? Don't have logic analyzer for clocks/waveforms
- T-Con failure likely?
- Should I expect white on 1/2 of screen with 1 panel flex disconnected from T-Con? I've seen this behavior before on a Samsung but perhaps its panel dependent?
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