Vizio E601i-A3 Won't Power On

[impala454]

I'm trying to fix a Vizio E601i-A3. User says after a lightning storm the TV quit powering on. I looked at the power board and there's a slight burn mark near the power connector near the fuse. I'm not super familiar with these types of fuses so I'm not sure how to tell if the fuse is blown (it has continuity on my DMM). The electrolytics all look ok. I get no voltage on any pin of the mainboard output connector. Here's some photos:

Power board overall shot


Power connector and fuse


This is the burn mark on the other side of the power connector


Main caps


Secondary caps


Any thoughts?

[dskall]

Re: Vizio E601i-A3 Won't Power On

What dv voltage do you get across the terminals of 450v capacitor. Picture 4

[impala454]

Re: Vizio E601i-A3 Won't Power On

About 210V

[impala454]

Re: Vizio E601i-A3 Won't Power On

(on both)

[dskall]

Re: Vizio E601i-A3 Won't Power On

What is your line voltage? You should list your voltage or country

[impala454]

Re: Vizio E601i-A3 Won't Power On

120v (us)

[CapLeaker]

Re: Vizio E601i-A3 Won't Power On

What are the voltages on CN201 when you plug in just the PSU, nothing else connected to it?

[budm]

Re: Vizio E601i-A3 Won't Power On

So the meter is good and set properly to read VDC between the two legs of the main filter cap?

[CapLeaker]

Re: Vizio E601i-A3 Won't Power On

the 210V DC on the main filter cap don't make any sense unless you have 150V AC input and I really doubt that one.

[impala454]

Re: Vizio E601i-A3 Won't Power On

Arg, I think my meter is messed up. Reading 14V on a fresh 9V battery and 1.9V on a 1.2V. I definitely was not getting anything out of the power connector though.

[budm]

Re: Vizio E601i-A3 Won't Power On

Get good working meter first before going any further, bad data makes it hard to troubleshoot the problems.

[impala454]

Re: Vizio E601i-A3 Won't Power On

Will do

[impala454]

Re: Vizio E601i-A3 Won't Power On

Ok, meter just had a dead battery and is working now. Both caps read about 160V.

[impala454]

Re: Vizio E601i-A3 Won't Power On

What are the voltages on CN201 when you plug in just the PSU, nothing else connected to it?

I'm trying to figure out where to measure it.

[CapLeaker]

Re: Vizio E601i-A3 Won't Power On

Unplug cn201 so that the pins are exposed. Find the gnd pins and put the black probe on there. Plug in the PSU and probe the other pins with the meter set to dc volt. I am looking for STBY voltage. That gives us a starting point.

[impala454]

Re: Vizio E601i-A3 Won't Power On

Ok gotcha, here's the connector:



Using pin 5 as ground, the only pins that showed non-zero voltage was pin 8 and 9, which showed 0.03V.

[CapLeaker]

Re: Vizio E601i-A3 Won't Power On

So there is no 3.3V DC on pin 1? That means we have to work on getting that going if there isn't any. If there is no voltage on pin 1, unplug the PSU from mains, put your DMM into diode mode and check between pin 1 and one of the GND pins for a short. What is printed on U501 on the back side of the board? If you follow pin 1 backwards, it goes to that U501 IC.

[impala454]

Re: Vizio E601i-A3 Won't Power On

Checked between pin 1 and 5 and got 0.390. 0.557 in the other direction.

Here is the back side of the board at U501

[CapLeaker]

Re: Vizio E601i-A3 Won't Power On

I can't see any markings on that U501. For me that IC is just black on that picture. Can you identify any printings on that IC?
Maybe you can put the black lead of your meter (set to DC V) to one of the GND pins and with the red lead from your meter probe all legs of U501, while the PSU is plugged in. Be careful though. Don't touch anything on the primary side of the PSU.

I see a new PSU cost something like $35 at SJ.

[impala454]

Re: Vizio E601i-A3 Won't Power On

So I read as best I could and looks like 3 lines of alpha:

549887
61833
36D5D

The legs all probed 0.1V or 0.

I keep wondering if that burn mark near the mains input has something to do with it.

Something interesting, I posted this other thread for a smaller 32" TV. These were both in the same apartment during the storm and both have the same issue (seemingly no power). I didn't find any burn marks on the other one but the main caps both seem to charge up.