xenius LCDX32WHD88 (B) Backlight problem

[Kevan02]

Hi

First i need to say my knowledge is very basic but have been researching the net to
fix my problem which follows

The tv when plugged in light's up to standby but when i try to switch it on the
backlight lights up for a few seconds then goes out. The tv is on as i get sound
and can see the picture on the screen if i shine a light on it. Having researched
the problem it seemed it was a inverter board problem so bought a replacement
inverter board) at same time noticed that their was a few bad caps on the power board
so replaced that as well hoping it would fix the problem but it still shut's down after
a few secs.

With my increased frustration i researched more that led me to the light test beside the
transformers and output leads and they all light up the bulb i also striped the tv down
to check for bad bulbs inside the tv but they all light up for a few secs when the tv
is switched on.

So all that has brought me here to ask for help as i don't know where to go next with the TV

Thx Kev

[ammarben]

Re: xenius LCDX32WHD88 (B) Backlight problem

first you have to post some pictures

[ammarben]

Re: xenius LCDX32WHD88 (B) Backlight problem

second do some mesurment voltage of all connectors with ther labels

[ReeceyBurger123]

Re: xenius LCDX32WHD88 (B) Backlight problem

We need photos of all the boards and how they are connected please.

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

Sorry took so long but here are the pic's

[ReeceyBurger123]

Re: xenius LCDX32WHD88 (B) Backlight problem

Ok do you have a digital muiltimeter to be able to test the voltage thats the psu gives out ?

[tom66]

Re: xenius LCDX32WHD88 (B) Backlight problem

Pictures really need to be clearer - more light and higher resolution. If your camera can't do high resolution, take multiple photos that we can look at separately.

[budm]

Re: xenius LCDX32WHD88 (B) Backlight problem

Need better pictures of the Inverter board, especially around the connector so we can see the name of the pins. It is made by CMO, can you read the P/N of this imverter board?

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

Here are some better/closer pics, and i have a multimeter but will need some direction on specific parts to test please.

Thx Kev

Oh this is all the info from sticker's on other side of inverter -:

Sticker 1
K$27 - D028708 - L$AHX915807D701A
I315B3 - 6UA - A401A

Sticker 2
27 - D028708
T87I029. 19 LF
E400003296 - 01L1

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

Could somebody let me know if the above pic's are ok please and sorry if Y'all busy

[budm]

Re: xenius LCDX32WHD88 (B) Backlight problem

https://www.badcaps.net/forum/attach...2&d=1436562696

The last 3 pins are the command signals form main board.
You have BL_ON (Backlights ON, >2.5VDC steady = ON)
I_PWM: Internal PWM DIMMING Control
E_PWM: External Dimming Control.

So what DCV do you have on all those 3 pins with ref to the chassis GND? Do you have steady 24VDC from power supply to run the inverter?

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

i am getting 24.3 on all 3 pin's continuous when i put tv on from standby. when in standby 00.03

[budm]

Re: xenius LCDX32WHD88 (B) Backlight problem

i am getting 24.3 on all 3 pin's continuous when i put tv on from standby. when in standby 00.03

That cannot be, those signals pin are 5V level, if you have 24VDC on all those 3 pins you have bigger problems.
Are you sure you look at the last 3 pins on the right side of the connector? What did you use for GND ref. for the meter?

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

Sorry was looking at wrong side to my total embarrassment. I am using the T.V metal frame for ground and on the correct pin's it reads -
3rd from last 03.16 continuous
2nd from last 03.28 continuous
last 02.53 continuous
when tv is on

[budm]

Re: xenius LCDX32WHD88 (B) Backlight problem

OK, they are all good.
Transformers testing will be the next step.

[Kevan02]

Re: xenius LCDX32WHD88 (B) Backlight problem

Was wondering if somebody could point me to anywhere i can get some instruction on testing the Transformers.

Thx