Vizio M370NV Powers on for 2 seconds then shuts down

[R_J]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

If there was an issue with the backlights I would expect they would shut down even in this test mode.
It does seem to point to the main board, being a vizio it could be the eeprom? You could try freezing the U53 eeprom ic. Either with cold spray or an inverted canned air.
freeze the eeprom with the tv unplugged, wait a few seconds then plug it in and turn it on and see if it makes a difference.
It could be corrupt data and when it hits that point it does'nt know what to do so it turns off

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

If there was an issue with the backlights I would expect they would shut down even in this test mode.
It does seem to point to the main board, being a vizio it could be the eeprom? You could try freezing the U53 eeprom ic. Either with cold spray or an inverted canned air.
freeze the eeprom with the tv unplugged, wait a few seconds then plug it in and turn it on and see if it makes a difference.
It could be corrupt data and when it hits that point it does'nt know what to do so it turns off

I sprayed the eeprom U53 with cold spray, waited a few seconds but still had the same problem. the TV Powers on with backlights,has the on screen vizio logo for 2 seconds, then blank white screen for 1 more second, then tv turns itself off

[R_J]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Did you spray it with the tv unplugged? then plug it in. The eeprom data is read when it is first pluged in, spraying it after that will not work

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

I can order and replace the eeprom to see if that fixes it, I think it was $15 from shopjimmy not sure what the shipping would be..or order a replacement Main Bd. shopjimmy price $39 and $10 shipping...other than either one of these do you have any further suggestions or tests I can do to point me in the right direction. please reply back. I am signing off and going to bed now. will check back tomorrow to see what you or anyone else says...Thanks again for all your help.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Did you spray it with the tv unplugged? then plug it in. The eeprom data is read when it is first pluged in, spraying it after that will not work

Yes I had the TV unplugged at the time I sprayed the eeprom, then plugged it in after that before turning on the tv. I can try it again.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Yes I had the TV unplugged at the time I sprayed the eeprom, then plugged it in after that before turning on the tv. I can try it again.

I just tried it again with it unplugged and it didn't change anything.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

If there was an issue with the backlights I would expect they would shut down even in this test mode.
It does seem to point to the main board, being a vizio it could be the eeprom? You could try freezing the U53 eeprom ic. Either with cold spray or an inverted canned air.
freeze the eeprom with the tv unplugged, wait a few seconds then plug it in and turn it on and see if it makes a difference.
It could be corrupt data and when it hits that point it does'nt know what to do so it turns off

At this point do I order an eeprom or main board??I don't really want to spend $50-$65 on this TV.

[Diah]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Man, resistor test for BL doesn't mean your backlight okay if you see lighting on. take the screen apart and inspect visually you will find the issue.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Man, resistor test for BL doesn't mean your backlight okay if you see lighting on. take the screen apart and inspect visually you will find the issue.

I have been thinking about doing that, I see the ribbon cables to the panel are at the bottom on this TV, I'm wondering if I could just take out the front bezel mounting screws and swing the panel forward enough to inspect the led's......I did unplug both ribbon cables to the LED'S and the TV still powers itself off. I'm not sure if the LED's must be connected to keep the TV powered on. ANYONE ?

[Diah]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

I have been thinking about doing that, I see the ribbon cables to the panel are at the bottom on this TV, I'm wondering if I could just take out the front bezel mounting screws and swing the panel forward enough to inspect the led's......I did unplug both ribbon cables to the LED'S and the TV still powers itself off. I'm not sure if the LED's must be connected to keep the TV powered on. ANYONE ?

most Tvs with out BL socket connected will turn off . same way if LED issue set goes to protecting mode.

take panel aside will not help .. need to remove it out and all defusser plate.. keep in mind to notice their order.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

most Tvs with out BL socket connected will turn off . same way if LED issue set goes to protecting mode.

take panel aside will not help .. need to remove it out and all defusser plate.. keep in mind to notice their order.

I did this on a 55" Vizio for my friend, we ended up replacing all the LED Strips, we marked all the defective LED bulbs and he saved the strips, if I have any that are open ( not lit ) I wonder if I can pull some from the other led strips he has and just change the bulbs as needed.

[budm]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

I had a 4 pack of 560 ohm resistors, I have connected them with small alligator clip leads and this did force on the power supply and backlights are on now...I did have backlights prior to this test but the tv would power itself back off in about 2 to 3 seconds...now that I have these resistors in place what would be the next step???? I tried to see if all led's are on but it's hard to tell from the back side, but it appears as if they are.

So the backlights come on and stay on as long as the TV is plugged into the AC outlet?

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Info Below on next post

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

So the backlights come on and stay on as long as the TV is plugged into the AC outlet?

With the resistors hooked up, mainboard disconnected and the power supply and backlights forced on then yes the backlights will stay on then as long as the TV is plugged in.....but with mainboard plugged back in to normal, the TV will power on and shows the Vizio Logo on the screen (backlights are on too) but the TV will power itself back off within 2 or 3 seconds...the amber vizio logo is normal..amber when tv is off and white when tv is on.

[budm]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Put everything back to normal, then monitor the BL-ON pin then turn on the TV while monitoring the BL-ON pin to see if it goes to >2V DC and then drops down to <1V in sync with the backlights behavior.
You also should report the Voltage of other pins of the power supply connector that goes to the main board as well.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

Put everything back to normal, then monitor the BL-ON pin then turn on the TV while monitoring the BL-ON pin to see if it goes to >2V DC and then drops down to <1V in sync with the backlights behavior.
You also should report the Voltage of other pins of the power supply connector that goes to the main board as well.

CN 202 connector at Power Supply to Main board.

Pin 1 5.1 VSB reading Is 5.38 V TV on or off is the same
Pin 2 5.1 VSB reading 5.38 V TV on or off is the same
pin 3 5.1 VSB reading 5.38 V TV on or off is the same
pin 4 SGND reading zero volts TV on or off is the same.
Pin 5 SGND reading zero volts TV on or off is the same.
pin 6 SGND reading zero volts TV on or off is the same.
pin 7 SGND reading zero volts TV on or off is the same.
Pin 8 12 V reading 12.04 when TV is on and zero v when off
pin 9 12 V reading 12.04 when TV is on and zero v when off
pin 10 12 v reading 12.04 when TV is on and zero v when off
pin 11 Remote On_Off reading 3.28 V when tv is on and zero when off
pin 12 BL On_Off reading is 3.28 V when tv powered on and backlights are on then drops to .75 V as soon as backlights are off ( when tv powers off by itself)
Pin 13 NC
Pin 14 Dim_Pwm_Signal reading 3.26V when tv is on and Zero when tv off

[R_J]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

The mainboard is telling the power supply to do what it should, turn on and then turn on the backlights. Since there is no backlight error signal etc. from the power supply back to the main, the main has no idea if the backlight is on or off and really does'nt care.
Thats why I suspect the main board, and it could be an eeprom issue or I suspect it is more likley a bga problem on the large chip.

[Diah]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

for me look after the age of the TV.. did the LED survive .. and they are edge one.. not direct.. only visual check can help.. beside the set just 37 size no risk to break down panel.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

The mainboard is telling the power supply to do what it should, turn on and then turn on the backlights. Since there is no backlight error signal etc. from the power supply back to the main, the main has no idea if the backlight is on or off and really does'nt care.
Thats why I suspect the main board, and it could be an eeprom issue or I suspect it is more likley a bga problem on the large chip.

I was thinking a bga problem myself, I tried cold spray on the large chip shielding, also tried heating up the chip and eeprom, and going back and forth with both cold and heat. none of this made a difference....I have a question, if I unplug both ribbon cables that go to the panel will that have any affect on the tv staying powered on? i was just wanting to try that in case there was a short somewhere going to the panel....also I don't see a T-Con board anywhere on this TV and none are listed on Shopjimmy.

[MisterD]

Re: Vizio M370NV Powers on for 2 seconds then shuts down

for me look after the age of the TV.. did the LED survive .. and they are edge one.. not direct.. only visual check can help.. beside the set just 37 size no risk to break down panel.

I may possibly do that first. before getting too far into this thing.