Acoustic solutions LCD26761HDF no backlight

[tom66]

Re: Acoustic solutions LCD26761HDF no backlight

eBay: http://www.ebay.co.uk/sch/i.html?_fr...All-Categories

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

And It is not there when you turn off the power switch? The 15vdc is correct since there is 15V Zener inside the IC.
At this point, it can be the IC is bad since it has the voltage but not sending out the drive signals (PIN 5, 7) to the two Gates of the MOSFET's. One thing I am not sure what those components on the left top corner are for yet. If you do have the 400Vdc feeding the MOSFET's, then I would try new IC.

Thx for your time & being patient with me..im getting 392vdc measured with fluke..theres this repair kit..do i need it all?
http://www.chsinteractive.co.uk/elec...3-q814-s-c.htm
I cant find the IC830 FAN7711 in my farnells catolouge..thx

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

And It is not there when you turn off the power switch? The 15vdc is correct since there is 15V Zener inside the IC.
At this point, it can be the IC is bad since it has the voltage but not sending out the drive signals (PIN 5, 7) to the two Gates of the MOSFET's. One thing I am not sure what those components on the left top corner are for yet. If you do have the 400Vdc feeding the MOSFET's, then I would try new IC.

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

Black lead to the ground pin4 (GND) of the IC, Red probe to pin 1 (VDD), just do not touch ANY METAL PART OF THE PROBE OR CHASSIS DURING THIS MEASUREMENT IN CASE YOU SLIP SINCE WE ARE WORKING ON THE AC PRIMARY SIDE OF THE CIRCUIT!

It measures 15.00vdc

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

Black lead to the ground pin4 (GND) of the IC, Red probe to pin 1 (VDD), just do not touch ANY METAL PART OF THE PROBE OR CHASSIS DURING THIS MEASUREMENT IN CASE YOU SLIP SINCE WE ARE WORKING ON THE AC PRIMARY SIDE OF THE CIRCUIT!

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

I saw that picture but not sure if pin 1 is connected to R976, JUMPER J152 and then goes down some where in the bottom right of the picture, we just need to verify if we do have DC power feeding the VDD PIN1 of the IC or not.

How am i testing pin1..tv on black probe ground screw red pin1..thx
Im getting 14.96vdc with tv on

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

I saw that picture but not sure if pin 1 is connected to R976, JUMPER J152 and then goes down some where in the bottom right of the picture, we just need to verify if we do have DC power feeding the VDD PIN1 of the IC or not.

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

OK, the next step is to find out if the PIN 1 (VDD) of the FAN7711 is getting the voltage feeding it, I have a hard time tracing out where it goes to in the pictures.

Does this pic help..thx
http://i1068.photobucket.com/albums/...5/P1000846.jpg

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

OK, the next step is to find out if the PIN 1 (VDD) of the FAN7711 is getting the voltage feeding it, I have a hard time tracing out where it goes to in the pictures.

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

Heres a pic..thx
http://i1068.photobucket.com/albums/...5/P1000843.jpg

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

Please look at the PDF, I need that P/N of the IC830 FOR THE 24VDC SMPS SECTION.
At this point the PS_ON is OK, the power supply with PFC controlled will use the same signal to turn on the PFC circuits and the 24VDC power supply section at the same time.

Thx budm its been a very loooong day..the IC830 is FAN7711 VJ28..thx

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

Please look at the PDF, I need that P/N of the IC830 FOR THE 24VDC SMPS SECTION.
At this point the PS_ON is OK, the power supply with PFC controlled will use the same signal to turn on the PFC circuits and the 24VDC power supply section at the same time.

[tom66]

Re: Acoustic solutions LCD26761HDF no backlight

I dont know what controller im looking for..the pics i uploaded from photobucket are they clear enough to trace the 24v line?

Not really.

It will be a chip of some sort on the primary side.

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

Hi tom..is the controller on any of the pics ive already posted..thx
When i mentioned about ariel in & having no signal display on screen..on the back cover of the tv next to the antenna it says 5vdc..am i right assuming that the antenna needs 5v if so thats not working aswell cos my ariel on my house roof is in perfect order with 100% signal on my nearly fixed lg 42"

I dont know what controller im looking for..the pics i uploaded from photobucket are they clear enough to trace the 24v line?

[tom66]

Re: Acoustic solutions LCD26761HDF no backlight

5VDC is probably for powered antennas... don't worry about it should be fine.

Near the power MOSFET for the 24V there should be an IC what is the name/number on it and a photo would be helpful can't make out much from your pics.

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

391V is okay, PFC is working.

Got a pic of the controller for the 24V (on the bottom of the board usually?)

Hi tom..is the controller on any of the pics ive already posted..thx
When i mentioned about ariel in & having no signal display on screen..on the back cover of the tv next to the antenna it says 5vdc..am i right assuming that the antenna needs 5v if so thats not working aswell cos my ariel on my house roof is in perfect order with 100% signal on my nearly fixed lg 42"

[tom66]

Re: Acoustic solutions LCD26761HDF no backlight

391V is okay, PFC is working.

Got a pic of the controller for the 24V (on the bottom of the board usually?)

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

I am confused, what DC voltage do you get on that large cap when TV is plugged in but not turn on, what is it when the TV is turn on?

Hi budm..im getting 342DC when just plugged in & same reading when power button pressed & blue led light on..thats with borrowed multimeter & 400V with my AC/DC voltmeter..thx
Getting 391DC when program button pressed as it must be on then & blue led is standby by..thx
So the cap is 450v is close to 400v enough?

[budm]

Re: Acoustic solutions LCD26761HDF no backlight

I am confused, what DC voltage do you get on that large cap when TV is plugged in but not turn on, what is it when the TV is turn on?

[sienoki]

Re: Acoustic solutions LCD26761HDF no backlight

That was scary but no permed hair lol
standby .946VDC
tv on 2.874VDC
.045 VAC &1.380 VAC from OL the readings werent steady they were up & down
Forgot i had this buried in cupboard..it read 400V in standny & tv on..thx
http://i1068.photobucket.com/albums/...5/P1000823.jpg
Should i recap all the psu caps with panasonics as they are all different named brands..or just hang on for now..thx

Ive just hooked up dvd player as ived not heard sound as yet & sound is fine..so its just 24v not getting to the inverter..the fuse on inverter is fine..something is shorted or failing but no idea what that could be