Samsung UE46C6005 only clicking

[budm]

Re: Samsung UE46C6005 only clicking

BTW, from the description of the power supply power relay clicking on and off when connected to the main board it sounds like the main board is not sending steady PS-ON signal.

[Stanem]

Re: Samsung UE46C6005 only clicking

OK, now I have connected the pull-up resistors - no clicking. As I can see I should have power on 1,4,5 and 8 at CNL801 but there I have a reading of 0.2 to 2.1 v (jumping up and down). On the other connector it looks like that the readings is OK. So I guess it seems to be something wrong with the backlight... is it "just to fix" the PSU or is there a reason (other than heat extinction) to why it broke down that I have to check up? I tried to connect back MB without backlight and then the clicking started again... is it because it is missing backlight?

[Stanem]

Re: Samsung UE46C6005 only clicking

I looked at the PSU, just went in and did some measuring like DRIVER_VCC is 12v Vdrv is varying up and down... when measuring in driver block there seems to be no voltage at all (backlight circuit). Any ideas?

[Stanem]

Re: Samsung UE46C6005 only clicking

Hi again - trying to wake up this project, haven´t had so much time for it until now... I still have problem with the PSU and it seems as it is the back-light part that gives me trouble. I have measured the voltages (S-GND as ref) and on Vdrv there´s 128V, on CNL801 there´s 340V on pin 1&5, on pin 4&8 0V. Driver Vcc is 14V. What makes me confuse is that on Q407&411´s drain the voltage is running from 100-1000V up and down as crazy, gate and source 0V... Anyone got an idea what to look for? Thanks in advance.

[zwarder]

Re: Samsung UE46C6005 only clicking

I tested the psu by resistor method & backlights were tripping out for about 10 seconds but then came up ok.
Possible backlight driver ic going bad?