Vizio E552VLE / Does Not Power On

[TheTesterMan]

Vizio E552VLE
Power Board 0500-0502-2020
Main Board 3655-0552-0150

Front Light Power-Up-Sequence
Amber light
Power Button -> White 6secs -> Off 1/2sec -> White 1/2 sec -> Amber
(the half sec off-white-amber occurs very quickly )

Power Board Power-Up-Sequence (see attached scope screenshot)
Power Button -> REMOTE pin goes high for 6secs,
Power Button -> after 1 sec, BL_ON pin goes high for 1 sec

Power Board Voltages (see attached scope screenshots )
5v = 5.2v clean
12v = 10.44v dirty
18v = 15.90v dirty
24v = 22.40v dirty

Voltage(s) Power-Up-Sequence
TV OFF
FilterCaps 160v
Standby 5v

TV ON
FilterCaps 350
Standby 5v
12, 18 and 24v

Questions
1. Are the power board voltages supposed to be this dirty ? I know these are not the best of components nor circuits, but the sawtooth V riding on the voltage rails are of a concern
2. What generates the BL_ON signal ? PSU or Main
3. Same for the REMOTE signal ?

Things I have tried
Checked many of the Power board components, many I have pulled from the board to verify ( especially the large Vcaps ). I have yet to find any issue with any of the components.
I have connected a 3.3v signal to the REMOTE pin to keep the Power Supply running so that I could check the Main board voltage regulators, so far no issues.
I am still unsure as to which of the 2 boards is the issue.

Thanks

[budm]

Re: Vizio E552VLE / Does Not Power On

PS-ON (REMOTE), BL-ON, and DIM are generated by the main board.
Pictures of the whole backside of the TV so I can see all the board.
So the PS-ON goes high for 6 seconds and then drops down to <1VDC? It should stay high until the TV is turned off.
If that is the case, the 24VDC power supply should also drops out.
Disconnect the power cable to the inverter and see what happen.
Check the DCV between the two legs of the main filter caps, it should jump up from 160VDC to >360VDC when PS-ON is present.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

PS-ON (REMOTE), BL-ON, and DIM are generated by the main board.
I was not aware that REMOTE is PS-ON, that explains quite a bit.

Pictures of the whole backside of the TV so I can see all the board.
Attached

So the PS-ON goes high for 6 seconds and then drops down to <1VDC? It should stay high until the TV is turned off.
Correct, PS-ON stays high for 6secs until the TV turns off.

If that is the case, the 24VDC power supply should also drops out.
Correct, the 12, 18 and 24 supplies drop out. Original post updated.

Disconnect the power cable to the inverter and see what happen.
Tried this, same sequence.

Check the DCV between the two legs of the main filter caps, it should jump up from 160VDC to >360VDC when PS-ON is present.
Correct. Original post updated.

I am still curious, are those dirty voltages acceptable for a TV power supply ?

[budm]

Re: Vizio E552VLE / Does Not Power On

Ripples are not that bad for raw Voltage outputs for 12V for audio power amp and 24V for inverter circuits.
To me you have main board problem because the PS-ON should not drop out.
Try disconnecting the Cable the T-CON board next, then the cable to the IR sensing board for the remote.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

I tried both, same results.

I will now concentrate on the Main board.

[budm]

Re: Vizio E552VLE / Does Not Power On

I am not sure if this model has problem with corrupted EEPROM or not.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

I tried to research this and got nowhere.. I was not able to find a EEPROM replacement.

[budm]

Re: Vizio E552VLE / Does Not Power On

Main board is not cheap for this TV, too bad the other threads do not have the follow-up on the repair after people spent lots of time helping.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

Yes they are expensive.. I would buy one, but not unless I knew it was %100 fix.
Since I have nothing to loose, I am going to try reflowing main board components. So far I cannot find the eerprom, it is not one of the 8pins, I looked all those up. So I am going to try to reflow the big FLash IC.

[mmartell]

Re: Vizio E552VLE / Does Not Power On

Before you throw it in a toaster heat the main uP with a hair dryer to see if your symptoms change. If you have bad solder joints the hair dryer should flesh them out by expansion.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

I have access to a reflow station, so I plan to reflow all the major main components.

[TheTesterMan]

Re: Vizio E552VLE / Does Not Power On

Finally got back to this project.

Had board reflowed using a reflow station. Unfortunately, I believe that made it worse. Regardless, still not working.

At this point direct replacement is >$100 which I cannot justify, not only because that is too pricey for a main board, but also because I am not %100 sure that this was/is the issue.

[Robert2526]

Re: Vizio E552VLE / Does Not Power On

Hey guys! I have this same model. The TV worked great and then shut it self down. Went to turn it on and the amber light flashed real fast for a minute. That was the last thing it did. Now it does absolutely nothing. I looked up a bunch of stuff on the internet which led me to the conclusion the power converter board was bad. Will I'm pretty handy with a lot of things but not circuit boards. So I jumped on line and ordered a new one from ShopJimmy.com. I put it in with no troubles at all BUT, I still have the same issue, no power. Any ideas!!!!

[budm]

Re: Vizio E552VLE / Does Not Power On

Hey guys! I have this same model. The TV worked great and then shut it self down. Went to turn it on and the amber light flashed real fast for a minute. That was the last thing it did. Now it does absolutely nothing. I looked up a bunch of stuff on the internet which led me to the conclusion the power converter board was bad. Will I'm pretty handy with a lot of things but not circuit boards. So I jumped on line and ordered a new one from ShopJimmy.com. I put it in with no troubles at all BUT, I still have the same issue, no power. Any ideas!!!!

What do you mean by 'POWER CONVERTER' board?
How about showing us the pictures of the board you replaced, and some DCV readings on the cold side connectors?