Sanyo FW42D25T

[nomoresonys]

Re: Sanyo FW42D25T

Wondering if UL2 is bad or could it be whatever feeds it voltage is bad, not even any guesses?

[nomoresonys]

Re: Sanyo FW42D25T

The most notable thing is, before backlights go off after 45 seconds both UL1 and 2 read correctly, when they go out UL1 still reads correctly but UL2 is dead, any ideas? thanks.

[nomoresonys]

Re: Sanyo FW42D25T

Thinking the problem might be one of those 2 resistors, the other one 200, reads 43 ohms in circuit, or maybe QB101 or CB116.

[nomoresonys]

Re: Sanyo FW42D25T

Thanks for reply, guess this model wasn't too popular, very few youtube videos of it. Going to trace it before removing it, see where it goes and see if I can decipher what it does. It's smaller than a grain of rice.

[diif]

Re: Sanyo FW42D25T

Resistor RB114 is marked 4r7 but reading 7.6 ohms, wondering if that would be bad enough to cause this problem.

You're measuring it in circuit ? Take it out to measure correctly.

[nomoresonys]

Re: Sanyo FW42D25T

If you look at the picture in post #1, it's that resistor right there by CB116 by the transformer. Also noticed that the underside of the board where this transistor QB801, located right by the backlight connector is discolored darker than the rest of the board, like it was maybe running hot or something.

[nomoresonys]

Re: Sanyo FW42D25T

Resistor RB114 is marked 4r7 but reading 7.6 ohms, wondering if that would be bad enough to cause this problem.

[nomoresonys]

Re: Sanyo FW42D25T

No, I lied, it does come back on, what it does is hit power backlights come on in 5 seconds then go off about 42 seconds later, every time.

[nomoresonys]

Re: Sanyo FW42D25T

After the 42 seconds and they go off, if I try to turn it off and right back on the backlights stay off.

[nomoresonys]

Re: Sanyo FW42D25T

Ok, so probably no boosted voltage in this tv, anyway the panel lights up, 48 leds, 8 across, 6 vertical, all leds are equally bright, then 42 seconds later they all turn off, tested both lines with backlight tester, have 64.5 on both. Kind of seems low if they are 3 volt leds.

[nomoresonys]

Re: Sanyo FW42D25T

Anyone know if these are supposed to have boosted voltage or not?

[nomoresonys]

Re: Sanyo FW42D25T

Having a little revisit with this one board pos, think it's bad backlight/s, current situation, tv comes on fine, goes blank screen after about a minute or so, sound still there, passes flashlight test, voltage on big caps is about 164 both when working with picture and when it goes dark, I don't know much about these one board tvs, do you think that it is only suppose to have 164 and not go any higher or is something else wrong other than backlights?

[nomoresonys]

Re: Sanyo FW42D25T

I for sure appreciate the help from Lotus and RJ but this one isn't worth wasting anyone's time on.

[nomoresonys]

Re: Sanyo FW42D25T

its an old tv from 2012, theres no value there, was only looking at it for the puzzle factor but really not curious enough to mess with it anymore.

[nomoresonys]

Re: Sanyo FW42D25T

to what end, no time for it, if you want it just hop on over and it's yours, no charge.

[diif]

Re: Sanyo FW42D25T

For the sake of a 5 minute soldering job
Do you not have a decent soldering iron?

[nomoresonys]

Re: Sanyo FW42D25T

already moved on, this one isnt worth time or energy.

[diif]

Re: Sanyo FW42D25T

Any progress on this? What soldering iron do you have?

[diif]

Re: Sanyo FW42D25T

A simple desoldering job that should take less than 5 minutes, what's the issue?

[nomoresonys]

Re: Sanyo FW42D25T

would have to remove heatsink to get to it, was hoping there was another way to proof it out.