VIZIO E550i-B2 Sound - No Video Problem

[ckramer]

Re: VIZIO E550i-B2 Sound - No Video Problem

Thinking we had an LED backlight issue, we removed the back panel to find a burned spot on one end of the pin plug connecting the power supply board to the LED board. (The burn spot is on the power supply board side) Is this our issue with the whole TV being dim but having sound?

[SLK001]

Re: VIZIO E550i-B2 Sound - No Video Problem

Thinking we had an LED backlight issue, we removed the back panel to find a burned spot on one end of the pin plug connecting the power supply board to the LED board. (The burn spot is on the power supply board side) Is this our issue with the whole TV being dim but having sound?

This TV doesn't shut down due to a backlight fault, so you can have both video and audio with no backlight. The black spot was due to the intermittent sparking of the remaining connections.

Your fix should be the one detailed in post #49. The way I would do it now, would be to alternate between top and bottom connection. If you use 22 gauge solid insulated wire, having four on each net will supply more than enough current. There is no need for the entire 8+8 that I used.

As for the fix in post #49, it was still going strong when I took the TV out of service in early March of this year.

[ckramer]

Re: VIZIO E550i-B2 Sound - No Video Problem

Thank you for taking the time to help with my issue. I looked at post #49. Please know that I am a female but I pride myself on watching fix-it videos and have saved myself tons over the years fixing my washer, dishwasher, etc. I'm determined to give this a shot as well.

I did fail to include a picture. I've attached one here. So replacing the whole power supply board is not necessary?

[SLK001]

Re: VIZIO E550i-B2 Sound - No Video Problem

Your picture doesn't show anything other than the black area. Take an extreme closeup of the BACKSIDE of the connector (the solder joints), like those shown in post #1. Only this type of picture will tell the tale.

[ckramer]

Re: VIZIO E550i-B2 Sound - No Video Problem

My sad attempt at soldering! I did this, put it back together, plugged it in and it actually worked for about 30 minutes. Then it returned to the dim screen with sound.

[SLK001]

Re: VIZIO E550i-B2 Sound - No Video Problem

My sad attempt at soldering! I did this, put it back together, plugged it in and it actually worked for about 30 minutes. Then it returned to the dim screen with sound.

You have to do them ALL. Looking at your picture, I can see that every one of the joints are broken. You need to do the fix in post #49. If you don't, your fix will just fail again in a couple of months.

As for your solder blob, get yourself some rosin solder flux (do NOT use plumbing flux). If you use an acid based soldering flux, you'll ruin your board.

[ckramer]

Re: VIZIO E550i-B2 Sound - No Video Problem

You have been tremendously helpful and patient. I'll certainly try what you have said and let you know if I'm successful.

[thstuff]

Re: VIZIO E550i-B2 Sound - No Video Problem

Fixed an E550i-B2 today with fractured Power Supply CN202 solder joints.

This failure may be due to a 3-4X difference in CTE (coefficient of thermal expansion) between the glass reinforced plastic chassis and PCBs clamped to it by 13 screws, resulting in high forces directly applied to CN202.

To remove the force on CN202 I decided to 'float' the LED Driver PCB as follows:
- Remove LED Driver PCB
- Under LED Driver PCB, trim off the plastic locating pin near upper left corner and both right edge mounting screw bosses flush with the chassis.
- Reinstall LED Driver PCB but do not install the two screws on left edge and replace the two right screws with a #6 screw thru PCB and metal ground tab secured with a nut.
The LED Driver PCB is now supported on the left by CN202 and right by the metal ground plate taped really well to the plastic chassis.

Will know if this helps in a few years