Mulja tv repair portal

Equipment Repairs => LCD TV forum => Topic started by: Chaos on August 27, 2009,18:07:18

Title: Toshiba 32hl57 LCD.Sound with no Picture.
Post by: Chaos on August 27, 2009,18:07:18

I'm new to this site,and new to electronic repair.

I have a Canadian Model Toshiba 32hl57 LCD television.
The problem I'm having is.When turned on,the back light will flash for a second or two,then go black.I do however get sound.

It was suggested to me that I replace the Inverter. So I did.Still no change.
Note:
When turned on,if i select the menu,I will get the blue screen background with menu but on for a second or two.

Any advice would be greatly appreciated.

BTW:I was trying to open this image,but with no luck.
http://www.tv.quuq.org/mkportal/image/inverter.JPG

Many thanks in advance.

Title: Re: Toshiba 32hl57 LCD.Sound with no Picture.
Post by: theo laird on August 27, 2009,18:15:01

Could be faulty ccfl tubes in display panel

Title: Re: Toshiba 32hl57 LCD.Sound with no Picture.
Post by: Chaos on August 28, 2009,11:31:21

I hope it's not the panel.and way to confirm that??

So..I've now managed to open the image.
http://www.tv.quuq.org/mkportal/image/inverter.JPG

Being from Canada.The wire color coding is different from the UK.
After taking a voltmeter to the traces connected to the 14pin connector on the inverter( right to left) .

Here are my findings

With power ON/OFF

VCC or VIN  #1(White),2,3,4,5(Grey) all read 24v/0.4v
GND  #6,7,8,9,10(Grey) all read 0v/0v
Error-Out #11 (has no wire connected) reads 1.3v/0.5v
ENA #12 (grey wire) reads 4.7v/0v
DIM #13 (grey wire) 3.2v/0v
Ex_DIM #14 (has no wire connected) 2.0v/0v

Note:
#1-9 from PS (P804A)
#10,12,13 to Digital Control PCB

According to:
http://beyondinfinite.com/lcd/Library/Samsung/LTA320WT-L06.pdf
All of my readings are within spec.

I hope this will help shed so light on my problem.
        

Title: Re: Toshiba 32hl57 LCD.Sound with no Picture.
Post by: greymatter on August 30, 2009,03:06:55

Do a continuity test on the inverter transformer windings, if one or more are open circuit then that may be your only  problem.

Title: Re: Toshiba 32hl57 LCD.Sound with no Picture.
Post by: sparky on August 30, 2009,06:27:38

hi
greymatter
the inverter board has been changed?