Vizio E552VLE Not Turning On

[ecking767]

Re: Vizio E552VLE Not Turning On

This is your EEPROM chip (see red arrow), try using a heat gun to heat up the chip and then try to power up the TV. Don't use too much heat, heat up the chip for about 15 to 20 sec.

[keeney123]

Re: Vizio E552VLE Not Turning On

I would go back to measuring the voltages as Bud M suggested. If your voltages are just a little out of spec. you can experience unusually behavior by digital circuits that depend on rise times to trigger circuits. Other problems that create unpredictable behavior are cold solder joints. Also, if a chip gets a static charge because one does not wear a grounding strap the chip can fail over time.

[tonelope10]

Re: Vizio E552VLE Not Turning On

How do I test those?

[tonelope10]

Re: Vizio E552VLE Not Turning On

If I don't have a heat gun can I use the wife's hair dryer? If it works would I need to keep heating it periodically or would doing it the one time fix it for good?

[Agent24]

Re: Vizio E552VLE Not Turning On

A hair dryer should work, but is rather wide-angle, so it can heat more than the target part. However, for this purpose, it's probably OK.

It's only for testing, not repair. The idea is that if it works when heated, you probably have an EEPROM chip with a heat-sensitive fault, and the chip should be replaced.

[tonelope10]

Re: Vizio E552VLE Not Turning On

The heat did not work, but the picture was not the same board so I might have been heating the wrong thing. If I knew for sure that it would work I would buy a new main board. Can someone walk me through how to tests those things that Bud M suggested....

[keeney123]

Re: Vizio E552VLE Not Turning On

One thing bud M ask was to look at the back of the panel in the dark to see if the backlights light up or if they light for a second and then go off or if the just do not light at all when you plug the TV in? The other readings you will have to know how to use your meter.

[tonelope10]

Re: Vizio E552VLE Not Turning On

Yes the backlights work. If I left the TV on it would stay on the startup "V" screen indefinitely. The problem is that only about 1 out of 20 or 30 times does it finish the startup "V" screen and go to the HDMI input so that you can watch TV.

[tonelope10]

Re: Vizio E552VLE Not Turning On

If I bought a new main board online for $150-$200 is it a pretty certain chance that this will fix it? Also, could someone talk me through replacing it. Looks fairly simple but there are a couple of very small connecections on left side that I'm not sure how to remove. Can it all be done without melting anything?

[keeney123]

Re: Vizio E552VLE Not Turning On

BudM was thinking it might be a T-con Board. I am not the expert that BudM is with LCD TVs He has a very clear knowledge of what has to be performed and what to look for. If he wanted you to take voltages than that was for a specific reason. I am sure this is to limit it down to which board. I would not buy a new board, but buy from a online parts like shop Jimmy's or TV tech parts. They will be a lot cheaper and still have a warranty with them. But at this point you would just be guessing if you just went ahead and replaced a board. With the methodical test that BudM ask you to perform you could get to a point that you would know what was wrong or if you did not exactly know at least it would be an intelligent guess.

[tonelope10]

Re: Vizio E552VLE Not Turning On

I have been trying to find info on how to test those things that BudM asked but I guess I am just not looking in the right places online. I've located most of the things he wants to test but not sure what to set my meter on, where the black pole needs to be when touching the red one to the location...etc

[Agent24]

Re: Vizio E552VLE Not Turning On

It seems he wanted you to check for some voltages on the PSU outputs. These voltages should be in DC, so you should set your meter to DC Volts.

The black probe will go to ground.

Check out https://learn.sparkfun.com/tutorials...e-a-multimeter as well, does this help?

[keeney123]

Re: Vizio E552VLE Not Turning On

This is what BudM asked. The CN's are the connectors on the power supply board. You will need to turn your meter to DC volts. If your meter has auto range it will set the range by itself. If not you will have to set it to dc volts then a range has to be greater than the highest voltage you will be measuring. You will have to know what the ranges are. An example is if you measure 5 volts DC you have to set the range greater than 5 volts. If you do not know what the voltage is on a pin you always start with the highest range and then go down one range at a time. The SGND is where your black lead of the meter goes when measuring DC voltage . The red lead goes to the positive DC voltage you are measuring. With digital meters if you connect it wrong you will get a negative reading. With an analog meter it will peg the needle against the post. You have a digital meter. The Connectors are clearly mark so you should not have a problem. Just read below what BudM ask and perform one reading at a time and write the answer down after each reading, also write down what you are reading ahead of time so after you read it you can just put down the voltage read next to the pin you are reading. If the pin say 5 volts your reading might be 5.075 V. There are other pins A,B,C so you would write down the A and the reading next to it. If you are going to repair electronics or electrical circuits you will need to be very familiar with your multi-meter.

OK, I found the good pictures of your DELTA POWER SUPPLY 0500-0507-0790 (DPS-321AP).
When the TV is not working, you need to verify that you do have >2VDC on the PS_ON pin of CN201 when the power switch is activated. If you do have PS_ON, then check and see if you do have 12VDC on CN201, 18VDC on CN204, 24DVC on CN202.
Also report the DC Voltage of A, B, C on CN202 when TV is OFF and when TV is turned on.
You should also verify that the backlights are on or not when it is not working, you may have to look at the back side of the panel in the dark to see if they are on. We need to know if you do not see the pictures on the screen is due to no backlights or the T-CON board is dead.
http://www.shopjimmy.com/vizio-0500-...upply-unit.htm

[tonelope10]

Re: Vizio E552VLE Not Turning On

OK for the CN201 PS-ON I got 3.20vdc.
CN201 had 12.09 vdc
CN204 had 19.46 vdc
I could not seem to get a reading from CN 202 with the TV turned on or off. I tried it from both sides of the plastic housing where the wires came in and could not get anything from where it said 24V or the A, B, C wires (B looked like it was empty where it was labeled) Could this be significant or was i just taking the readin wrong?The little metal box next to it appeared pretty warm after just a few seconds of being on.

[keeney123]

Re: Vizio E552VLE Not Turning On

This is where BudM needs to step in. It would seem to me that 3.2 vdc on CN201 is correct and the 12.09 vdc is correct. On CN204 it is 1.46 vdc above the 18 volt reading and to me would seem off. This is where BudM knowledge of these boards would be beneficial.I would need a schematic of this board in order to tell how this is being generated. I believe the CN202 24 volts is feeding the inverter circuit for the backlights and from another thread I read one of the A,B,C connector turns on the Backlights when the 5 volt stand-by power is connected to it. Also, when the 24 volts turns on, the thread says that the main filter cap will jump from 160 volts DC to greater than 360 volts DC. So be very careful around those big capacitors. So, if you are not getting the reading on the 24 volt line I would suspect the backlights would be off. After you take the 24 volt reading and get 0 volts DC reading you could turn off the lights to see if indeed the backlight is not lighting and perhaps BudM will jump in and take you the rest of the way.

[tonelope10]

Re: Vizio E552VLE Not Turning On

ok thank for your help. I will wait and see what BudM says regarding this. I did get a little shock from the metal box below CN204 that just scared me when it hit my hand. I can see lights through the back of the screen while its stuck on the "V" screen and I was assuming those were the backlights, but maybe I am mistaken? Like I said the TV comes on and just gets stuck on the startup "V" image which I would imagine requires the backlights?

[budm]

Re: Vizio E552VLE Not Turning On

OK, PS _ON is OK otherwise you will not get the 12V and the 18V (this one is not tightly regulated), BUT you should have 24V for sure since the 12V, 18V, and 24V are generated by the same power transformer T601, so you need to check the 24V current path connections really well.
The A,B,C signals are from the main board and are routed through the power supply board for clean wiring, A and B are for the BL_ON and DIMMING but I do not remember which is which, C is not used. There should be 0 Volt when TV is off and >2.5V or so at those pins when TV is switched ON.
Pictures provided by shopjimmy.
Do not touch any thing on the board with your hands, you should plug your TV int GFCI outlet at least.

[tonelope10]

Re: Vizio E552VLE Not Turning On

Is it possible that I'm not checking the voltage in the correct places? The wires were easier to check on Cn201 and 204 but they go farther into the plastic on CN202. Should I be checking where the wires go in or at the base of the plastic housing?

[budm]

Re: Vizio E552VLE Not Turning On

CN202 (pin 1~5) and CN203 (pin 1 ~ 5) are connected in parallel so you should be able to check for 24VDC at either one of those connectors.

[tonelope10]

Re: Vizio E552VLE Not Turning On

I can't seem to get a reading for those. If I put a paperclip or something metal around the tip of the red lead I could probably get far enough down to get a reading but I'm not sure how dangerous this might be...?