Technika LCD 40-270 Voltages Gradually Drain

[steved271]

i have a 40 inch Technika LCD that was gifted to me as it just sits with the Red Power LED showing....

when the standby button is pressed, it just does nothing....

i assumed it was the power board that was at fault so ordered a replacement... this does exactly the same thing... but can not confirm whether this was a good board when it was purchased....

so i decided to do some diagnostics..... when i test the voltages when i press the power on button and i get 24v but as i go further down the power starts draining to zero volts....

is this because it has done its tests found a fault and powering down?

I am about to check the Voltage sent to the LCD power board on the far left and see if this gives me any voltage


If anyone has any ideas i would appreciate them

steve

[ReeceyBurger123]

Re: Technika LCD 40-270 Voltages Gradually Drain

Common issue on the, trash TMSD boards it eh epprom that stores the firmware fails causing a similar issue. Have you dissconected the inverter and tried to power on the Tv ?

[dick_barton]

Re: Technika LCD 40-270 Voltages Gradually Drain

Can you check your power supplies on the bench and see if both of them come up with the expected voltages normally written on the PCB alongside the connectors?

[steved271]

Re: Technika LCD 40-270 Voltages Gradually Drain

Reece, I am still working on this one.... Its not an urgent fix as just one i got as a throw away.... I disconnected the Inverter board and nothing happened.....

Because the Voltages come up as the set tries to power on and then drains away after about a minute, I am guessing something is tripping the protection circuit.... I tried another inverter which i know is good....

I saw from one of your vids about the Caps on the main board.... I am going to see if i can get hold of a Cap meter to test those.... but will look for the EEPROM and see what it is.... Any Tip on where to get a replacement or where to get the firmware from?

Dick, All the voltages check out fine..... Its just when the standby switch is pressed that it sits for a moment and then the voltages drain to zero....

[dick_barton]

Re: Technika LCD 40-270 Voltages Gradually Drain

I have just replaced the mainboard on a Technika 46-270 after being stuck in standby.

Do you have access to a scope? I scoped the clock line of the SPI chip (U10) when I tried to take it out of standby but there were no clock pulses to be seen.

A replacement motherboard was ordered because I considered that the main processor was not communicating with the SPI.

All up and running now.

[steved271]

Re: Technika LCD 40-270 Voltages Gradually Drain

Dick, No i dont have access to a scope... Thank you for that... I will order one and see if it gets it working....

The SPi chip is for the firmware? I been having a nose around and cant find the Firmware from anywhere....

[dick_barton]

Re: Technika LCD 40-270 Voltages Gradually Drain

If it is the firmware then it's available from
http://www.ohmsupplies.co.uk/epages/...jectID=6766894

[steved271]

Re: Technika LCD 40-270 Voltages Gradually Drain

Cheers, I will get that ordered today and and post back when i have replaced it...

[steved271]

Re: Technika LCD 40-270 Voltages Gradually Drain

Just a Quick update on this .....

I replace the U10 as suggested above and the TV Powered up like a dream....

Thank you for the advice

[dick_barton]

Re: Technika LCD 40-270 Voltages Gradually Drain

Well done and thanks for the update which could prove useful to others with a similar fault.

[ReeceyBurger123]

Re: Technika LCD 40-270 Voltages Gradually Drain

Good work again

[steved271]

Re: Technika LCD 40-270 Voltages Gradually Drain

Its always good to post the fix so others can benefit from it