Rank Arena 32" LCD TV Repair TL3291

[grasshopper]

Hi All,
The project is a model TL3291.
The red LED light comes on on power up / standby mode but when the TV on button is pressed nothing happens.
I have confirmed mains voltage to the power supply board and checked the power supply fuse on the board which appears sound.
Visually I have lookes at both boards for any signs of swollen or damaged electrolitic capacitors but can see no obvious damage.
The TV is about 4 years old but has had little use.
What is the next stage of diagnosis please?
Is it checking all the electrolitic capacitors on both boards wih an ESR tester?
Checking voltages where marked on the boards?
Some other approach?
Any advice and wisdom would be greatly appreciated please?
Thanks
grasshopper

 

[(*steve*)]

Do you have a service manual for this set?

 

[grasshopper]

Schematic

Hi Steve,

I have only managed to source a schematic so far which I have attached. I have yet to confirm this matches the board I have.

Thanks
Grasshopper

 

[sheldonstv]

what you need to do is check the supply is giving you the correct dc voltages -as its an lcd start by pulling the lead to the inverter board and see if the set powers up with sound but no picture-at this point you can also check the 24v supply is present for the inverter too-another possibility may be that the inverter is ok but you have a fault with your ssb panel ....post pics of your set if you can

 

[grasshopper]

board photos 1

Board photos

 

[grasshopper]

Board Photos 2

Photos 2

 

[grasshopper]

Hi Sheldon,
Board photos as requested.
Kind regards
grasshopper

 

[sheldonstv]

yes i know this set have had a few of these im looking for the manual,this set also turns up as a badged bush set or hitachi .....do you not have any voltage to the inverter board at all-24 v not present?no standby supplies present?are the voltages not marked by each socket on that board? if i remember rightly there was a psu repair kit available for one of the bush models

 

[grasshopper]

G'day Sheldon,
On the Power supply board there are voltages and grounds marked beside the connector. I have measured these and will post the results later tonight.
I have not measured the Inverter board supply and I am not sure which connector it is as yet? I think the connector shown top left in photo 2236 (two white and one black cable) has Inverter etched on the board beside it and I will check that out as soon as I can , probably tomorrow night and post the results here.
Many thanks
Kind regards
Grasshopper

 

[grasshopper]

Voltages Measured

Hi Sheldon,

Below are the voltages measured with the power on and the red standby LED illuminated:

Cable Colour Voltage Etched on Board Voltage Measured
White 12V 0.9mV
White 12V 1.0mV
Not used Gnd
Black Gnd
Not used Gnd
Not used +5V
White +5V
White +5V SB 5.16V
White PS-ON 3.63V
Not used +5V
White +5V 0.69V
Black Gnd
Black Gnd

This is the connector located top right in photo 2336 of the power supply board.
I am not sure what the voltages measred so far tell me as the circuits are not loaded?
any wisdom would be appreciated.

grasshopper