Samsung LN32D403e2DXZA

[dprit]

Customer brought this 32" in. Set will come on and you will have sound but the picture is only on for half a second. Sound is still there. Shut it off and same thing - sound always but picture for half a second. There is 12v on inverter board all the time. I replaced the main but same problem. What am I missing? When the picture is on, it looks a little dark. I see no lights behind the panel when it goes dark.

[anupkg1985]

Re: Samsung LN32D403e2DXZA

Do you have backlights on any time? Could you check with flashlight if picture is still there on screen?

[budm]

Re: Samsung LN32D403e2DXZA

Customer brought this 32" in. Set will come on and you will have sound but the picture is only on for half a second. Sound is still there. Shut it off and same thing - sound always but picture for half a second. There is 12v on inverter board all the time. I replaced the main but same problem. What am I missing? When the picture is on, it looks a little dark. I see no lights behind the panel when it goes dark.

Please attach pictures of the whole backside of the TV showing all the boards using 'GO ADVANCED' function so we can see what we are dealing with.

[nomoresonys]

Re: Samsung LN32D403e2DXZA

Unplug tv from power, unhook cable from powerboard to mainboard, leave unhooked, plug power cord back in to powerboard, do backlights come on and stay on?

[dprit]

Re: Samsung LN32D403e2DXZA

Backlights come on for half of a second then go out and stay out.

[nomoresonys]

Re: Samsung LN32D403e2DXZA

Backlights come on for half of a second then go out and stay out.

And THAT happens when you do the test in post #4 or did you not do the test?

[dprit]

Re: Samsung LN32D403e2DXZA

The answer to post #4 is the back lights come on for a half a second then go off. And with a flashlight , I can see the picture. I have replaced the Inverter and the main and still have no back lights.

[nomoresonys]

Re: Samsung LN32D403e2DXZA

Ok, You could check the voltage between the main filter cap think it's CP803s, meter set to 600 vdc, black neg. probe on neg. leg, red pos. probe on pos. leg, check it in standby/tv plugged in but turned off, take note then hit power take note, be VERY CAREFUL not to touch anything with your hands, HIGH DEADLY VOLTAGE on this hot side of powerboard.

[dick_barton]

Re: Samsung LN32D403e2DXZA

What voltages do you have at CON001 on the inverter board?
Pin 9 OVP =
Pin 10 CNT_PRT =
Pin 11 VCC =
Pin 12 LD =

And also CN802

[dprit]

Re: Samsung LN32D403e2DXZA

The voltage across CP803s is 166v SB and 393v when the set is on. Voltages at CON001 on the inverter board when on are: pin 9- 0 volts, pin 10-8.4volts, pin 11-12.7volts, pin 12-0volts.

[dick_barton]

Re: Samsung LN32D403e2DXZA

Pin 12 LD must initially be taken high at power on because you say the backlights flash and then either due to, for example, a lamp or transformer fault, it is being switched off.

[nomoresonys]

Re: Samsung LN32D403e2DXZA

There's a bunch of inverter boards on ebay for 11 bucks and up, electroparts has one but if it's a lamp issue then a new inverter won't fix it of course.

[dprit]

Re: Samsung LN32D403e2DXZA

I have replaced the main and the inverter boards with no change. I'm leaning towards a lamp problem. Asking the customer a few more questions, I find this tv is in a bathroom. Maybe the moisture caused a issue with the lamps. Thanks for the help!

[TVAddict]

I have the same exact TV with the same exact problem.

My readings on connector CN1801 are as follows - LD - 0volts / Vcc - 12.6v / CNT_PRT - 8.4v / OVP - 1.8v

Readings Taken with TV on.


Readings Taken with TV on.

The other pins with Low (fet) and high (fet) i'm not sure how to measure those?

at turn on High reads about upwards of 140v AC then dies off to around 19v AC

Low starts at 19v AC goes up to just 20v AC and drops back to 19v AC - i get no readings using the DC scale.

i tried another inverter board same problem, could it be power supply related or maybe i have a light failure/issue as well?

Any ideas help is appreciated.

[TVAddict]

Forgot to ask, if it is some light issue as this thread is mostly suggesting, is there a way one could force the lights to stay on?

[nomoresonys]

Forgot to ask, if it is some light issue as this thread is mostly suggesting, is there a way one could force the lights to stay on?

Unhook all connectors from the powerboard, plug the power cord into powerboard, plug into power, check voltage on all the pins of CN802 connector, meter set to vdc, neg. probe on chassis ground, pos. probe on each pin, take care to only touch one pin at a time, report results. If you don't have an auto ranging meter, set meter to 20 vdc.

[TVAddict]

Unhook all connectors from the powerboard, plug the power cord into powerboard, plug into power, check voltage on all the pins of CN802 connector, meter set to vdc, neg. probe on chassis ground, pos. probe on each pin, take care to only touch one pin at a time, report results. If you don't have an auto ranging meter, set meter to 20 vdc.

i did measure voltages at CN802 but with ALL connectors hooked up and TV on - pins 1 - 7 = 12.6v pin 11 and 13 = 5.6v pin2 = 0.76v pin12 = 5.2v pin14 = 3.5v pin6 = 5.1v - but all voltages were steady, tv remains on with sound just the light cuts off after a few seconds of the tv turning on. Also voltage at the main cap is steady at 394v

But i'll try what you suggested and see what readings i get...

[TVAddict]

with all connectors off readings on CN802 are :
pins 1 - 7 = 13v
11,13 = 5.2v
14 = 3.3v
12 = 5.2v
2+6 = 0v

Tried the light test in post#4 - the light flashed for a second and turned off
Tried leaving the OPV pin disconnected = same problem
tested the 474j cap it read 460, i figure that's still workable..?

[TVAddict]

hey guys i decided to take the TV apart and have a look at the lights, turns out it is the problem as suspected, as you will see in the pictures, one of them ( the middle light ) is literally busted, so that's it for me, it's the garbage for this tv, thanks to this thread and everyone for your help..