Vizio service manuals

[JohnCT]

I can get some through my parts supplier but not this one. I'm looking for a manual for an E550i-B2.

Anyone have a source? Thanks.

John

[SLK001]

Re: Vizio service manuals

Most manufacturers no longer release a service manual, since almost no one repairs anymore.

Your TV has sound, but no video, correct?

[budm]

Re: Vizio service manuals

I can get some through my parts supplier but not this one. I'm looking for a manual for an E550i-B2.

Anyone have a source? Thanks.

John

May be you can tell us what the TV is doing or not doing.
Have you done any Voltage testing?
Upload good clear pictures will also help.

[JohnCT]

Re: Vizio service manuals

May be you can tell us what the TV is doing or not doing.
Have you done any Voltage testing?
Upload good clear pictures will also help.

The TV is fixed.

I was unable to find a manual for this model. I do have some manuals for various Vizios so if anyone needs one, let me know.

As far as this TV goes, I'll give you some info on this job and after a couple of guesses (or by 4:30 before I leave work), I'll tell you what happened if someone doesn't get it. This one kicked my ass but good...

Symptom: Turns on, displays Vizio "V" logo (nice and clear, no lines, no irregularity in the brightness for the short time it's on), then shuts off.

Restarting duplicates symptom.

Measurements: During the time it's on (logo on screen for two seconds), the two power supply voltages appeared normal. That is, the standby 5V supply read 4.995, the 20V run source (feeds LED board and main board) read 20.05. Scoping them showed no abnormal sagging during startup.

I tested the run voltage of each LED strip to eliminate a low current/overvolt shutdown of the array that would occur with an open or lazy LED, and all strips showed a run voltage of about 18.5 give or take a tenth.

On the LED drive board, there are two identical boost buck converters fed from the 20V supply. One supply feeds half of the Source pin of the sink mosfets for the LED strips and the other buck conv supply drives the other half. When the power button is pushed, the 20V appears on the LED drive board and both buck converters immediately pump up the 20V to 23V (before the LEDs light). When the LEDs light, one of the two identical buck converters jumps to 26V and the other stays at 23V. The TV then shuts down. I swapped the two drive ICs from one side to the other but the voltage on that side stayed lower than the other.

I then ordered an LED drive board from Ebay but nothing changed, including the identical readings. I ended up isolating the gate pin of the buck converter mosfet of the side that stayed low and ran a jumper from the side that ran normally. Both converters now jumped to 26V on start but the TV still shut down. Since the pwm input to each buck converter IC are independent of each other and are sourced from the main board, I ordered a main board, also from Ebay. Problem remained, all voltages remained the same.

Changed: LED drive board and main board with used parts. No change of symptoms.

To add more crap to this, this TV suffered water intrusion. The main board was rusty around the BGA shield, and if you can even believe this, the ebay board was rusty when I got it! The LED board was also crusty with drippings but a soak in the cleaning tank left it nice and clean but with no change of symptoms.

Guesses?

John

Okay, one hint so this doesn't get out of hand.. It had nothing to do with the water leakage..

[budm]

Re: Vizio service manuals

So what DCV do you get on the Cathode return side of each LED strings? You have 12 Strings of LEDs.
http://www.shopjimmy.com/vizio-91-76...led-driver.htm
That is not much of the Boosted Voltage when feeding Voltage is 20V.

[dick_barton]

Re: Vizio service manuals

Was it a led fault or an open circuit somewhere in the led connections?

[JohnCT]

Re: Vizio service manuals

So what DCV do you get on the Cathode return side of each LED strings? You have 12 Strings of LEDs.
http://www.shopjimmy.com/vizio-91-76...led-driver.htm
That is not much of the Boosted Voltage when feeding Voltage is 20V.

Good question.

The high side of the LED strings were either 26 or 23, depending on which group of strings buck converter was feeding. Looking at the SJ picture, the six sink mosfets on the right side (three in front, three in back row) averaged about 0.5 volts when the LEDs were actually on, but varied between 0.4 and 0.6. The left group of six (the side fed by the 23V bucked voltage) were about 0.10 volts.

This means the voltage across each LED segment was between 23 and 24.5V. Seeing that my earlier test returned readings of 18.5 volts at 20ma, the voltage taken under full run seems correct.

Another hint: The voltages across the LEDs were actually normal! This TV uses local dimming and the difference between the two buck converters is normal as is the voltage across the strings. My supposition is that the LEDs under the Vizio logo were running at higher voltage.

In any case, for the sake of brevity, eliminate the LED strips and the LED drive board as the cause; they weren't...

John

[budm]

Re: Vizio service manuals

So what other board did you replace beside the LED driver board and the main board? I am assuming the TV is running right now with ALL original boards, correct?

[JohnCT]

Re: Vizio service manuals

So what other board did you replace beside the LED driver board and the main board? I am assuming the TV is running right now with ALL original boards, correct?

Yes, all original boards are back in, and both boards I bought are verified to be good. Because it was my error and the ebay boards were good, I'm not sending back the boards I bought.

Last hint: The problem was on the power supply board!

Recap: There are two secondary voltages on the power supply, the full time 5V "standby" supply to the main, and the high current 20V full run source that provides power for the LED drive board and run voltages for the main board.

Both voltages read normal, neither showed any abnormal noise on them, and neither line sagged when the TV powered up. I even subbed in my bench supply for the 5V source (even going up to 5.20V) and then for the 20V source (but not at the same time), and the main board continued to shut down after the logo appeared on screen...

Why would the problem be on the power supply board when the voltages read what the printed callouts said they should be? Did I say this one kicked my ass?

John

[budm]

Re: Vizio service manuals

But did you check the ACD signal which is generated by the power supply board to tell the main board if the incoming AC is within the operating range?
http://www.shopjimmy.com/catalogsear...lt/?q=E550i-B2

[JohnCT]

Re: Vizio service manuals

But did you check the ACD signal which is generated by the power supply board to tell the main board if the incoming AC is within the operating range?
http://www.shopjimmy.com/catalogsear...lt/?q=E550i-B2

Aaaannd we have a winner...

I've seen plenty of ac_det failures, but never one that would allow the TV to boot or come out of standby on command as this one did. Add to that it was intermittent and sometimes would come on normally.

The ac_det voltage was about 2.95V and solid. Without a schematic I couldn't be sure what it should have been. That's where I was when I joined this group and requested a manual.. but I digress.

I've seen anything between 2.4 and 4.5 volts for the ac_det voltage depending on who made the supply. And since every other example I've seen of ac det failures caused no boot or no attempt at start, I initially dismissed the reading. Having exhausted just about everything else, I returned back to the ac_det line.

I subbed in a clean supply and when I got to 3.1 volts, it stayed running every time.

Turns out that C958 (on the bottom) right off the opto was slightly leaky. On my old LC-75, 5v would cause it to show some leakage. It read .1 uf so that's what I put in.

With the new cap, the ac_det line read 3.3V, and that fixed it.

Your gift card is in the mail...

John

[dick_barton]

Re: Vizio service manuals

Glad you got there in the end. Something worth remembering.

[budm]

Re: Vizio service manuals

The ACD failure is common in Sharp TV due to bad OPTO or the resistor network, there are many threads on this ACD problem.
Most TV's do not employ the ACD function.

[jlapage]

Re: Vizio service manuals

John CT. Do you have the service manual for a Vizio E390-A1?

[burnvictim]

Re: Vizio service manuals

JohnCT do you have a service manual for an e55u-d2?

Thanks

[alfatv]

Re: Vizio service manuals

Looking for D50f-E1 or similar SM

[edhuk]

Re: Vizio service manuals

Looking for service manual for VIZIO M43-C1
Many thanks!

[neilc6]

Re: Vizio service manuals

Looking for service manual for VIZIO M43-C1
Many thanks!

M43-C1 has bad BGA connections on the mainboard. Search M43-C1 or M65-C1 and you will find many threads.

[Antonchuk]

Re: Vizio service manuals

Hi! I am looking for D50f-E1. Many thanks to everyone who responds.

[Mbd3]

Re: Vizio service manuals

Hi I am hoping someone can steer me in the right direction. I have a e550i-b2e tv. Smps delta dps-167. Anyways my Vcc to ic901 the standby is just jumping from 11 to about 13.9 volts. Just constantly fluctuating, and according to the spec sheet I need atleast 16v to start it. Any thoughts? Oh and I am a complete newbie to this.

Thanks