Telefunken 40DTU652 No Sound, no image, no backlight.

[Raulnn]

good evening! I have this tv with the following symptom. The tv is in standby, you turn it on, and the led blinks until it seems to start, but there is no sound or image or backlight.

When it is started for about 5-10 minutes, it goes back to standby by itself. I have taken voltages at the rear light output. with the back light connected, in standby there is 50v on the black wire and 0v on the red wire, and when you turn on the tv the voltage rises to 100v and stabilizes around 80v, with a return of 8v. The problem is that from time to time this voltage is lost and it is not stable. If you unplug the taillight the same thing happens.

I have taken output voltage measurements at the source, having 12, 5, 3.2 and 24v on and 8 and 1.4 v on standby. I am doubting the main, when the instability occurs with the rear light connected and not connected. the fixture has a 17mb130s main and a 17ips72 power supply.

Let's see what idea you can give me, very grateful in advance

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

somebody could help me?

[Diah]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

search the forum.. download and flash firmware yours mainboards label vestel 17MB130S

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

....

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

search the forum.. download and flash firmware yours mainboards label vestel 17MB130S

Thank you very much for answering. Do you think that the symptoms are compatible with the main board? a question, perhaps absurd. To flash, is it done through usb? or should the nand be desoldered? I'm a beginner, so I'm interested in buying a new main board. if i buy a new main can i buy any make and model of tv? I don't know if it should be exactly the same model. I don't mean the motherboard model, I know it must be 17mb130s

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok sorry, I have seen that it is the firmware, so I imagine that it is by usb. but I don't know if it will work with a generic from vestel or if I have to look for a specific one from telefunken. Thank you

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

update. I tried to update firmware, but the usb wouldn't boot. I turned on the TV again and... it started to play when I changed the channel. it changes channels and it can be heard... from what I get that it is the backlight... it is very difficult to see the image... the same thing the panel is darker. I think it's going to be the backlight. Does anyone have their opinion?

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

yep, could be backlight issue or maybe the mainboard isn't sending the backlight on signal to powerboard, probably need to do some testing.

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

yep, could be backlight issue or maybe the mainboard isn't sending the backlight on signal to powerboard, probably need to do some testing.

Thank you. Can you give me guidelines for testing?

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

can you post some good clear straight on pictures of each board and one of the whole back as to see how everything is connected.

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

Is there a legend/map of the expected voltages on the powerboard? being a vestel prolly not.

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

Is there a legend/map of the expected voltages on the powerboard? being a vestel prolly not.

Ok. Poder supply: 17IPS72
Main : 17MB130S


if, as you say, the sideburns are not marked. I made some measurements that I put in previous messages, but if you tell me specific measurements I will put them. Thanks in advance

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok, very carefully test the 2 biggest capacitors on the powerboard, meter set to dcv, a probe on each leg, careful to only touch it with the probe ends, not hands, theres high voltage, can be DEADLY, test it with tv turned on.

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok, very carefully test the 2 biggest capacitors on the powerboard, meter set to dcv, a probe on each leg, careful to only touch it with the probe ends, not hands, theres high voltage, can be DEADLY, test it with tv turned on.

392v. In addition, the current voltages towards the main are 12, 3.2, 5 and 24 v. In my humble opinion the power supply is ok.

[yokoono]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

First REPAIR THE BACKLIGHT. Then we'll see.

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok, very carefully test the 2 biggest capacitors on the powerboard, meter set to dcv, a probe on each leg, careful to only touch it with the probe ends, not hands, theres high voltage, can be DEADLY, test it with tv turned on.

Fault

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

First REPAIR THE BACKLIGHT. Then we'll see.

I appreciate the answer, but I don't want to be changing pieces without meaning. That was the first thing I thought, but I would like to make sure of the result. It is a TV that does not have great value

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok, well as its not a big screen, I would just take it down to backlights and see if they or their connection/s are the issue, takes some labor but doesn't cost anything but time, just have to treat the panel as if it was a baby so it don't break or crack.

[nomoresonys]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

392v. In addition, the current voltages towards the main are 12, 3.2, 5 and 24 v. In my humble opinion the power supply is ok.

ok, thats good, shows youre getting proper voltage there.

[Raulnn]

Re: Telefunken 40DTU652 No Sound, no image, no backlight.

ok, well as its not a big screen, I would just take it down to backlights and see if they or their connection/s are the issue, takes some labor but doesn't cost anything but time, just have to treat the panel as if it was a baby so it don't break or crack.

Thanks everyone, I'm going to wait for other leds to arrive and close another TV, and open this one. I already tell the solution. a greeting