UMC M40/57G-GB-FTCU-UK not powering up

[Andyd1970]

Hi Guys,

Been asked to look at this set for a neighbour, it is a UMC.

M40/57G-GB-FTCH-UK
UM40D57BFTCUG143

You power it up, get the red light and thet it turns blue you hear a sound from the PCB on the left side of the TV (looking from the rear) you hear a sort of fizzing sound from the PSU after a second or two, the blue light stays on for around 8 seconds, then turns red and it just cycles doing that. Cant see any obvious damage to caps etc, any thoughts please.

[ducky29]

Re: UMC M40/57G-GB-FTCU-UK not powering up

Its is probably a firmware problem. Try finding the appropriate firmware for this tv/board

[vinceroger69]

Re: UMC M40/57G-GB-FTCU-UK not powering up

umc do have a web site regarding firmware not sure what the price is though
http://www.umc-uk.co.uk/firmware.php
as you know sometimes freezing/heating the eeprom ic will get the set too work if this is the case you maybe able too read the firmware

[R_J]

Re: UMC M40/57G-GB-FTCU-UK not powering up

you hear a sound from the PCB on the left side of the TV (looking from the rear) you hear a sort of fizzing sound from the PSU after a second or two

There is either a fault with the backlight inverter (likely faulty transformer) or a bad ccfl lamp. Remove the metal shield and reinstall the screws to hold the board in place, the screws also ground the board to the chassis. Try the set in a dark room to see if you can see any arcing on that board, The next thing to check would be for bad connections on the transformers and also check the dc resistance of the transformer secondaries, and compair the reading to the others on the board.

What is happening is the backlight is trying to start up, detects a fault and shuts down.

[vinceroger69]

Re: UMC M40/57G-GB-FTCU-UK not powering up

like r_j says check the inverter circuit and ccfl lamps first i have seen ohms do a eeprom for this set so it maybe issue too.

http://www.ohmsupplies.co.uk/epages/...roducts/E2P184

[Andyd1970]

Re: UMC M40/57G-GB-FTCU-UK not powering up

Hi all, I have removed the metal frame, I tried to remove the PCB but it is secured by the whiteish pleastic pieces on the edge of the PCB, so shall I just power it up now with frame off to look for arcing? or shall I just replace frame and try it?

Thank you

[vinceroger69]

Re: UMC M40/57G-GB-FTCU-UK not powering up

those white plastic pieces maybe the ccfl tube connectors so just be careful you dont crack any tubes i would power the set up in a dark room and see if you can see whats arcing, you may have to put the screws back on the pcb as may use them to ground the pcb.