Vizio E470i no power

[AcGeorgiegirl]

Hi everyone,
I've replaced the power supply board to no avail. Here's what it's doing...It sometimes will give a blue(standby?) light, but this light quickly fades to nothing(weird??!!). I've checked the pins on the connector...standby is at a bit over 5v, blu is 0(after the multimeter cycles down in numbers), and pwm1 and pwm2 are both at 0.96. The pson is also at 0 after cycling down. I haven't tried testing the main side yet, because I really don't know where to start. i've never tested diodes and bridges and whatever other thingys I keep hearing about, but I will give it a try. My multimeter doesn't give esr values, unfortunately, to start testing the caps. I didn't think caps would be the first priority?

[Hamie]

Re: Vizio E470i no power

Disconnect the main board,

Jump ps-on to 5v
And also bl-on to 5v

All voltages should now be present and the back light should turn on.

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok. I don't know what you guys mean by "jump", sorry I'm sure I can do it, but could you give me an idea of what you mean? Thanks!

[Terryfictv]

Re: Vizio E470i no power

Put a straight pin in the connector with the wire at bl-on,
sb5v and ps-on then use alligator clip leads to hook them
together.....HTH

[Hamie]

Re: Vizio E470i no power

Ok. I don't know what you guys mean by "jump", sorry I'm sure I can do it, but could you give me an idea of what you mean? Thanks!

No probs,

Disconnect the wire going to main board,

Then with a piece of wire, paper clip etc, you need to connect ps-on to the 5v line. And also bl-on to 5v

Kinda like this,

[AcGeorgiegirl]

Re: Vizio E470i no power

Thanks for the 'splainin, guys! Ok. So I did the jumpering for both ps-on and bl-on with no change/nothing happened. I also got a little different readings for the various pins using a smaller wire attached to my DMM. The standby's were exactly the same. The pwm's were at 1.82, the 12v's were at .17.

[AcGeorgiegirl]

Re: Vizio E470i no power

I now have connected a 2nd power supply I'd bought, did the jumpering, and still got nothing. I then tested the pins as before, and got these: standby's are same(5.26), pwm's are 1.77 and 12v's are 0.14. Something else...the previous power supply didn't get me a blue "on" light, but this one does. Just to remind you..the blue light comes on, then fades to nothing within 5 seconds. It won't come on when I press and hold the power button more than 2 seconds.

[CapLeaker]

Re: Vizio E470i no power

With the power supply mounted and hooked up, measure every pin to GND. Use the pin out and the volts you measured.

[AcGeorgiegirl]

Re: Vizio E470i no power

With the power supply mounted and hooked up, measure every pin to GND. Use the pin out and the volts you measured.

ok, so "hooked up" = main board connected...or plugged into power supply?
Please give me details of how to measure pins to GND. Would I use black probe to a GND pin and red one to each of the previous pins I've mentioned(ps-on, pwm's, 12v's, and BLU? "use pin out"?

[AcGeorgiegirl]

Re: Vizio E470i no power

Guys, I'm wondering about this...If the pwr supply isn't connected to the main, and the only other connection to the tv is (what I am assuming) being the backlight panel, how would the ps-on get it's switch, considering the pwr supply isn't talking to the main. I understand that by jumpering v's to the ps-on and blu, I'm giving it a "direct switch" of power, but I get lost as far as how the pwr supply can then tell the main to turn the power on. I guess the other issue is that the psb didn't do its job in turning on the backlight, which is connected, anyway. Here's a pic of the layout, which might help you "get" why I'm confused about the switching issue.

[Andrew F. Ali]

Re: Vizio E470i no power

ok, so "hooked up" = main board connected...or plugged into power supply?
Please give me details of how to measure pins to GND. Would I use black probe to a GND pin and red one to each of the previous pins I've mentioned(ps-on, pwm's, 12v's, and BLU? "use pin out"?

Use this as an example:
Pin 1 ps-on 3.15Vdc
Pin 2 BLU 3.65Vdc
Pin 3 12V 0Vdc
Pin 4 Stby 5Vdc
etc
etc

Note: Your DMM should be set on the 20V DC Scale. The BLACK probe must be attached to the bare metal frame and the RED probe carefully placed on the pins.
Hope this helps.

[newtothis]

Re: Vizio E470i no power

Ok What happens is the 5v STBY is routed to the mainboard... When the mainboard is switched on it send voltage to the PS-ON pin of the PSU allowing the other voltages to rise.

So first thing is we should be telling you to use a resistor to jumper the pins not just a wire. So get a ~500ohm resistor and connect it from 5v STBY to PS-ON and measure voltages with Red to pin and Black to the chassis (Ground)

List the Pin name and readings like this :

Pin 1 - 5V STBY - 5v
Pin 2 - PS_ON - 5v
Pin 3 - 12v - 12v

etc etc

Make sure you are using VDC on your meter and not VAC, If your meter is old make sure your battery is good too.

[AcGeorgiegirl]

Re: Vizio E470i no power

Got it, thanks! I've been searching for a resistor with no success, among my graveyard of tv's to fix in my den! I know what they look like, but don't know how to determine ohm values except by their colored bands. I've been looking for either a 4 or 5-banded R. 4's with colors green, brown, brown, gold. 5's with green, brown, brown, black, red. Is this correct?

[budm]

Re: Vizio E470i no power

Resistor codes:

[Andrew F. Ali]

Re: Vizio E470i no power

OK. If you can't find a 500ohm resistor (I could only find 470ohm) then look for a 1Kohm resistor. That will be one with 1st band-BROWN (1), 2nd band-BLACK (0), 3rd band-RED (00). GOLD or SILVER for the 4th band but is not important right now.
On the Power Board jack P701 with the TV plugged in the AC measure Pins10-15 and 20-21 and see if you're getting 5Vdc.

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok What happens is the 5v STBY is routed to the mainboard... When the mainboard is switched on it send voltage to the PS-ON pin of the PSU allowing the other voltages to rise.

So first thing is we should be telling you to use a resistor to jumper the pins not just a wire. So get a ~500ohm resistor and connect it from 5v STBY to PS-ON and measure voltages with Red to pin and Black to the chassis (Ground)

List the Pin name and readings like this :

Pin 1 - 5V STBY - 5v
Pin 2 - PS_ON - 5v
Pin 3 - 12v - 12v

etc etc

Make sure you are using VDC on your meter and not VAC, If your meter is old make sure your battery is good too.

I got this started, but made a goof somehow, because a cap blew the second I touched the red probe to the 5vdc pin! I also found a blackened area nearby the cap, so I'm assuming I did some damage somewhere along the cap's trace? The cap is a 47uf 50v. That's the first time I've had this mishap, and it gave me a "come to Jesus" moment, as we say here in the South. Just to clarify, I was supposed to test dcv while the ps-on pin was jumpered over to the 5vdc, correct? I'm wondering if how I connected ac would have mattered? I used the tv's cord, which is only a 2-prong, but connected it using my 3-prong extension cord.

[AcGeorgiegirl]

Re: Vizio E470i no power

OK. If you can't find a 500ohm resistor (I could only find 470ohm) then look for a 1Kohm resistor. That will be one with 1st band-BROWN (1), 2nd band-BLACK (0), 3rd band-RED (00). GOLD or SILVER for the 4th band but is not important right now.
On the Power Board jack P701 with the TV plugged in the AC measure Pins10-15 and 20-21 and see if you're getting 5Vdc.

I didn't get to test the p701 pins, yet, due to my mishap with the cs201 pins, but I'm also not finding this jack on the board at all. Only other connector is the CN301 with pins for vout and led.

[newtothis]

Re: Vizio E470i no power

Ok pics are very unfocused TBH.

That's a SOT23 package transistor that's blown by the looks of it.

Can you give us the part number off the PSU please as may need to find a schematic

[AcGeorgiegirl]

Re: Vizio E470i no power

Ok pics are very unfocused TBH.

That's a SOT23 package transistor that's blown by the looks of it.

Can you give us the part number off the PSU please as may need to find a schematic

PN: 00500-0614-0270
*fyi, I'm confused about the pic's...they are huge, but clearly focused when I click their links

[AcGeorgiegirl]

Re: Vizio E470i no power

Any luck getting the schematics? I've looked everywhere I can think of. I failed to mention that when I blew the cap, the resistor I found to use was a 1k ohm, as pictured. I couldn't get a macro shot close enough to see the color bands for you guys, sorry.