VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

[budm]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

ok but a diode that can pass current both ways is defying the normal concept of what a diode is, isnt it?

Because you are testing the diode in the circuit which it is more likely to be connected in parallel with a resistor. The real way to test the component is to remove it and test it off the board.

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

ahh i see... i didnt realize diodes had to be removed to be tested...
should i just remove all components in the 24/12v section and test them?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

little help please? anyone?

[stj]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

you only need to de-solder & lift one end of a diode for testing.

[budm]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

OK, check the DC voltage using the negative leg of the main filter cap for Ground, then check the DC voltage on BOTH end of that R948, it should read 370VDC.

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

in post 1 i already checked and rechecked those voltages and it is marked that i got 370VDC

[budm]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

Just want to be sure nothing changed. Post 11, please get the P/N as printed on top of that SMPS IC for the 12V/24V so we can get the spec sheet and do the resistance and voltage test. Also check C941.

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

it says ET1103 or FT1103 (this is the 4 legged IC in the 12/24v)

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

i believe this is the datasheet
seem to only be able to find datasheets for TCET1103
..how can i be sure this is the same?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

why does this datasheet not have a numbered graphic explaining the pins?? the dot signifies pin1, but nowhere in the sheet do they label the emitter, collector, anode and cathode.
so is the emitter pin1? i have no idea!

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

c941 checks out at 10.something uf and 1.9 ESR is that too high of ESR?
at what point do we say the ESR is too high and the cap has failed?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

please can someone tell me what is a good ESR and what is an unacceptable ESR? where is the line?

[stj]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

there is no easy line - you compare against the datasheet.
what make, series, size, uf/voltage is it?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

its an elite 10uf 50v
i think EG(M) is the series but it may be cut off as its a pretty small cap.
5mm diameter
12mm tall

dang now that you mention it i should have known this already to try look it up in the datasheet. they do say values of ESR in there dont they?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

hrmm..not having any luck finding this datasheet. what search terms should i be using?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

woah its gotta be here. this place is loaded!
ftp://helpedia.com/pub/temp/datashee...ets%20Set%204/
i couldnt find EG(M)
but i found EG
is that the same thing? or does the (M) have to be in there?

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

hmmm... i dont see any mention of ESR in this datasheet :/

[stj]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

it says 1.45ohms

max impd = impedence, same as ESR


hmmm - 1.9 is a lot more than 1.45
i'd say it's fucked.

[aaronwt6]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

I just thought I'd throw my two cents in on this having only skimmed over quickly what has been said. I just had 5 of these TVs in my procession. 4 of the 5 were not responding to the power button. Also, FYI, I believe these all show a dim white logo when in standby and it turns brighter when the power is turned on. Not positive, but I believe this one is that way and does not have an amber light.

Regardless, one of the 4 that were not turning on had a bulged capacitor on it which drew my attention. I don't recall the value off hand but in your first post its the capxon capacitor just above the heat shield. It is in between two other branded capacitors.

Anyway, I changed that just for the heck of it and the TV turned right on. Due to this fact, I changed that capacitor on the other three boards and they worked as well. No testing was done on that capacitor and I'm not sure what its function is on the mainboard but I was 4 for 4 on it fixing them. Even though 3 of them did not look bad.

Worth a shot at least if you are sure the power supply is ok. The 5th one I had the power supply would only put out standby voltage.

[triplefour]

Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.

wow thanks for the info, if you fixed 4 out of 5 by changing that cap then its definitely worth taking a look at.
but i am a little confused by the way you worded things
"Worth a shot at least if you are sure the power supply is ok."
i mean...its not ok, right? thats why we're going to change the capacitor. did u mean to say "worth a shot at least if you are sure the motherboard is ok?"
either way im doing it
thanks man