fighting a sony xbr65x850C since the beginning of november.
Original issue - no power
replaced power supply
power but scrambled looking HDMI
replaced main board
mainboard was actully for the 55" version (identical) and powered on to blinking yellow and green ( i think)
took EMMC from old main board, read on EMMC reader, made backup of both new and old EMMC (so we know for sure they are both readable)
reballed and transferred to new main board. Quite certain no issue in the physical swap, but who knows.
back to no power.
Standby is there, power VCC and VVCq to EMMC is there. No shorts on EMMC as far as i can tell from the external components. (CMD CLK DAT0)
Was about to start soldering wires for ISP to make sure my EMMC swap went well, and decided to test the power supply.
External 3.3 supply connected to power_on BL_on tcon_on
tcon voltage 12V
BL voltage 93V on out- 222V on out+ with ground plane ground reference.
Backlight does not light up
dc dimmer to 3.3v or ground changes nothing. Same for PWM dimmer.
All voltages as the connector seem to check out
I am fully willing to accept the main issue lies in the EMMC swap and the contents there of, and i should be able to work through it, but this backlight issue makes zero sense to me. Could a crappy backlight have been my "power" issue all along? Any way to bypass protection if there is any?
No light on the optical audio, and no 5 volts on USB, but main IC heatsinks are getting warm. So somthing is happening. A debug UART would be excellent, but i don't see anything obvious.
any ideas or where to go from here?
Original issue - no power
replaced power supply
power but scrambled looking HDMI
replaced main board
mainboard was actully for the 55" version (identical) and powered on to blinking yellow and green ( i think)
took EMMC from old main board, read on EMMC reader, made backup of both new and old EMMC (so we know for sure they are both readable)
reballed and transferred to new main board. Quite certain no issue in the physical swap, but who knows.
back to no power.
Standby is there, power VCC and VVCq to EMMC is there. No shorts on EMMC as far as i can tell from the external components. (CMD CLK DAT0)
Was about to start soldering wires for ISP to make sure my EMMC swap went well, and decided to test the power supply.
External 3.3 supply connected to power_on BL_on tcon_on
tcon voltage 12V
BL voltage 93V on out- 222V on out+ with ground plane ground reference.
Backlight does not light up
dc dimmer to 3.3v or ground changes nothing. Same for PWM dimmer.
All voltages as the connector seem to check out
I am fully willing to accept the main issue lies in the EMMC swap and the contents there of, and i should be able to work through it, but this backlight issue makes zero sense to me. Could a crappy backlight have been my "power" issue all along? Any way to bypass protection if there is any?
No light on the optical audio, and no 5 volts on USB, but main IC heatsinks are getting warm. So somthing is happening. A debug UART would be excellent, but i don't see anything obvious.
any ideas or where to go from here?
Comment