Vizio E550i-B2E How did I fix this?

[Gaines]

Ok so 13 months ago I bought my Vizio E550i-B2e from good old Wal-Mart and it went dead 2 weeks ago. No picture, no sound, no backlight. Thank goodness I purchased the 3 year extended warranty eh? Well they inform us that there are no local technicians to come service it so they send us a brand new one. That's what brought me to this board!

So after the new TV arrived yesterday, I take the back off of the old one and inspect it and take some volt readings to prepare to repair it. From the power board it bridges to another board....T-con? (See pics). When I took those reading I got a small spark...and WALLAH! The TV powers on and works great! How did this happen?

Just to clarify, I was taking the readings from CN201 that connects the power board to the board in the center using the chassis as ground.

[freakaftr8]

Re: Vizio E550i-B2E How did I fix this?

It's because that jumbo connector that connects to the power supply to the backlight control board has bad solder connections on it theres like 16 pins. Remove both the power supply and the backlight control board and resolder all the pins on each of the connectors. There's your problem I've dealt with this before on a few of these models.

Edit: This is CN202 where the problem lies.

[budm]

Re: Vizio E550i-B2E How did I fix this?

That big green board in the middle is the LED drivers board, check for bad solder connection on the square inductors (two of them with L330 printed on top) for the Boost converter circuits to drive the LEDS (It has 12 LED drivers on that board).

[Gaines]

Re: Vizio E550i-B2E How did I fix this?

Thanks a million guys. Can't beat having a free tv!

[freakaftr8]

Re: Vizio E550i-B2E How did I fix this?

So was it the soldering underneath the connector?

[Gaines]

Re: Vizio E550i-B2E How did I fix this?

Honestly, I don't know. Since it's working perfectly(for now), I didn't take it apart again. I assume it's a bad solder on that big connector from the power board to the LED driver board. I will know what to look for if it happens again.

But you were right, it was CN202.

[Alastair E]

Re: Vizio E550i-B2E How did I fix this?

Its terrible, innit....

More poorly made cheap plastic Chinese Crap lasting to just outside warranty.....

Summit needs to be done about this. 14 months then failing is NOT of Merchantable Quality.

[snapcaseacilec]

Re: Vizio E550i-B2E How did I fix this?

That big green board in the middle is the LED drivers board, check for bad solder connection on the square inductors (two of them with L330 printed on top) for the Boost converter circuits to drive the LEDS (It has 12 LED drivers on that board).

I just fixed an issue except the bad solder was on the back side of the light brown board on the left (power supply) and not the green (LED driver) board. I made a 2 separate solder bridges across the rows, length wise.

[rjcalifornia]

Re: Vizio E550i-B2E How did I fix this?

Glad I found this forum. You guys are awesome. Got a free 60'' today cause my old 55'' was going out, had extended warranty. I knew the power supply board was my problem but I did know it was the 16 pin connector on the brown board. Thanks for the info.

[mandacat]

Re: Vizio E550i-B2E How did I fix this?

It's because that jumbo connector that connects to the power supply to the backlight control board has bad solder connections on it theres like 16 pins. Remove both the power supply and the backlight control board and resolder all the pins on each of the connectors. There's your problem I've dealt with this before on a few of these models.

Edit: This is CN202 where the problem lies.

If your having an LED backlight problem with Vizio models such as - that use a separate led driver board - you'd be well served to heed advise from freakaftr8. I have found the same issue as he. The connector from the power board to the led driver board has bad (aka "cold") solder joints under the power board side. Even if your particular issue is different, suggest you check as it is only a matter of time before this problem will also cause backlight failure.

Mandacat

[glen4cindy]

Re: Vizio E550i-B2E How did I fix this?

I just fixed an issue except the bad solder was on the back side of the light brown board on the left (power supply) and not the green (LED driver) board. I made a 2 separate solder bridges across the rows, length wise.

I am trying to repair a board just like this with bad solder joints just like the rest of these here.

I'm not proficient at "reading" board traces.

What I am trying to find out, is row 1 on this connector a single connection electrically as far as the board is concerned? Then it looks as if the top 4 solder points on row 2 are a single connection electrically. The next 3 look as if there is no connection.

If what I think I am seeing is correct it will make my limited soldering ability easier to deal with these tiny connections.

I'm just wanting to make sure I am seeing this correctly. I've heard of multilayer PCB's and want to make sure this isn't one of those.

Thanks in advance.

[SLK001]

Re: Vizio E550i-B2E How did I fix this?

The connector only has two signals - +V and GND. One row is +V and the other row is ground. The bad solder joint is on the PS board, which is a single layer board. Do NOT leave this unrepaired, as the OP seems to have done. If not repaired, the TV will experience times when it works and times when it does not.

[glen4cindy]

Re: Vizio E550i-B2E How did I fix this?

The connector only has two signals - +V and GND. One row is +V and the other row is ground. The bad solder joint is on the PS board, which is a single layer board. Do NOT leave this unrepaired, as the OP seems to have done. If not repaired, the TV will experience times when it works and times when it does not.

Thanks much!

Will be soldering today and then giving it a try.

[glen4cindy]

Re: Vizio E550i-B2E How did I fix this?

Success!

I used a hot air rework station and flux paste to remelt the solder on this connector and corrected the cold solder joints.

A working TV for my happy friends who now do not have to replace their 2 year old TV.

Thanks Badcaps and all the helpful folks here!

[glen4cindy]

Re: Vizio E550i-B2E How did I fix this?

I'm curious. I was able to fix this issue with this TV, and this seems to be a common problem with this model.

However, this TV was in use for almost 2 years before this "cold solder joint" problem disabled it.

How does this happen? If it's a cold solder joint, and basically a "design flaw", how does it work for so long before quitting?

Thanks,

[SLK001]

Re: Vizio E550i-B2E How did I fix this?

How does this happen? If it's a cold solder joint, and basically a "design flaw", how does it work for so long before quitting?

Thanks,

It's just luck. It is a stochastic process. Solder under stess will slowly flow to relieve the stress, cracking and losing electrical connection along the way.

[Sam2356]

Re: Vizio E550i-B2E How did I fix this?

New to the site, Awsome just wanted to say thanks for putting my mind at ease. I just fixed this problem yesterday. Vizio was no help at all TV 3yrs. old. Just found this site today scanning cold solder joints. you can bet next time i have a problem i'll be looking here first. thanks