Samsung QM49R 49" 4K UHD not working

[suiramix]

Hi there,
Samsung tv, like new condition ( Aug 2019), plugged-in, power up (without pressing the power button) with backlight on but no start up sound, no image. Cannot be power off by the switch or remote. Removed screw-less back cover and inspected the power supply and main board…no suspected components… disconnected one or both LCD ribbon cables, same status. Voltages 13V and 3.3V are OK.
However, when is plug-in, the main board has a chirping sound for 3 to 5 sec before backlight is starting. At this point I want to confirm that it is a hardware or software issue. For a better access, removed the processor (huge) heatsink and checking for short to ground of capacitors and coils. The microprocessor is powered by TPS56C20 (12-A synchronous buck converter) and the output coil L324 show low resistance measured to ground 2.8 ohm. The coil output voltage is 0.80V stable. On the back site of board (same location) there is a capacitor C336 showing same resistance. Is that normal ?...

[suiramix]

Re: Samsung QM49R 49" 4K UHD not working

Just a quick update…having no info regarding this tv, I assumed this situation was due to incorrect setting from EPROM or corrupted firmware. To access the service mode menu (Factory Reset), press the buttons on the remote in this order: Mute, 1, 8, 2 and Power when the tv is on stand-by mode…so I have up to 5 sec for this operation… the front red led was blinking / responding to the remote … the backlight turned on (nothing new) …but I heard loud and clear ”Please select your language” message…but no image on the screen !!! Next, tried to power off using the remote … worked but it restarts by itself after 5sec ! My guess is somebody messed up the service menu setting or firmware update and I am stuck on initial set-up with a blank screen. The tv is detected by my laptop when the HDMI cable is connected (as Samsung 48”)… any ideas...thanks!

[dick_barton]

Re: Samsung QM49R 49" 4K UHD not working

Are you able to install the update firmware for the set.
https://displaysolutions.samsung.com...-support/QM49R

[suiramix]

Re: Samsung QM49R 49" 4K UHD not working

Hi Barton, yes, came across that website (1.1GB firmware file) ...I have a RS232C to aux cable but need also the loader software to install the new firmware. Where I can find those info? Thanks!