Hello! I am trying to fix a Vizio LED TV that does not power on at all and has no LED lights lit, and have followed a few YouTube videos. I dont have all of the details of the TV in front of me but the Model Number is e480i-b2. I have tested the voltage from the SB 5v source and found that the voltage fluctuates up and down between about 4.5 to 6.5. When I disconnect the supply to the main board, the SB voltage goes to 0. I have checked all of the capacitors and everything else I could and everything seems to test fine and visibly look perfect. I have search this symptom over and over again and cannot seem to find anyone that has reported their SB powers fluctuating up and down. Due to the videos I have watched I have already ordered the main board hoping this will fix it, but I’d like to know what would cause the voltage to fluctuate up and down like that. I saw one video where they thought it was a capacitor. Thank you very much for your help!!

Neil Frazier

• 42 Answers
• Posted on Jul 06, 2008

SOURCE: Westinghouse LTV-32w6 power light on, no video, no sound

One thing is to make sure the inverter board is unplugged when testing the voltages. A shorted inverter will shut down the power supply if the fuse dosen't blow first. There are fuses that don't look like fuses so they can be missed. The next thing would be to look for a connector from the main to power supply and see if there is a pin labeled power on or p.on or similar. The main board should turn this line high(5V) when you push the power button. If not you probably have a bad main board. Unless you can find good used boards they are both expensive. Around $200 for PS and $300 for main.

SOURCE: power supply is bad on philips plasma 50 inch tv, it just clicks

nice job... thats the most common problem with all LCD tv's now

Bud Martin

• 11361 Answers
• Posted on Dec 09, 2009

SOURCE: Protron PLTV-3250 back light inverter?

I use hair dryer for locating bad electrolytics capacitor for almost 30 years. When its warm up the chemical reaction works more than when it is cold, that is one symptom of bad electrolytic cap. When you cool down the cap with freeze cooler then the set will stop working again. I would say go ahead and replace those capacitors on th inverter board, make sure to use low ESR capacitor such as PANASONIC FM series from DIGIKEY.COM. I use these cap for repair for many many years with great reliability. The inverter board should have 24vdc feeding it.

Testimonial: "Thank you very much for the information. This inverter board is not a typical push through hole type board, anything i should be aware of doing this?"

SOURCE: WD-62525 My tv wont work. new lamp does not work. have tried ever

Check all fans incuding the one on the cage of the lamp. if they spin when you turn the set on then they are ok. the color wheel needs replaced. if you can't replace the color wheel then order the optical engine.

Ginko

• 19396 Answers
• Posted on Sep 13, 2011

SOURCE: how do I test the y-sustain main board from a

Hi.

As such boards are cheap and fail quite easily (both the two sustain and the buffers) Philips service manuals are more oriented at board swapping then at proper testing. In this particular case the buffer boards fail very easily because of a bad soldering to IC. The short will regularly blow the main sustain board.

To start when a main sustain (e.g. Ysus) is fried the TV will go in protect mode with the led flashing in standby. One test is done disconnecting the Sus board (with power off) and restarting the TV. If TV does not go in protect, then the sustain board was good.

If there is no protection:

The first thing to check on a main sustain board is the fuse. If the fuse has blown the IC is probably fried.I believe fuse is F5004. Check for swollen capacitors that may have blown. Test the FET. That is the core of the board as it is the power amplifier.


Here the service manual:PHILIPS_SM_15540.pdf - Right Click "Save Target As"

Here a more useful service manual. Check and follow troubleshooting diagrams in manual.

Here some troubleshooting from users.

Note:if buffer board was shorted, then the main sustain board is usually faulty.

Regards.

Ginko