55" Vizio XVT553SV Powering off problems

[Go Cards]

So I've been living with this issue for a couple of years, resetting by unplugging but slowly it's been getting worse & worse. now the TV only stays on for 10 seconds then powers off. Once it turns off, the power button doesn't work unless left alone for about 30 minutes, then it will power on for the same 10 seconds then power itself off again. If I unplug it, then plug it back in, I only have to wait about 2 minutes for it to power on for the same 10 seconds.

I have the back off, looked hard, but don't see anything burned or bulged. All fuses are good. I have made some measurements; 5.17 Volts standby from PSU and at fuse on main board; 12.32 Volts to main board fuse after power button is pushed. Even after the TV shuts down after 10 seconds the 12.32 Volts remains on main board and T-Conn board for about 20 minutes then the voltage goes to zero. Even though the 12.32 Volts is there during the 20 minutes, the TV power button does not work.

I have read all posts on Badcaps Forum for this TV, a couple are close to my issue, but none show a complete resolution. Hope someone can help me find the root cause, not just changing boards... unless that's the only way! The TV is 3 years old (from Costco) - Thanks!

[Hamie]

Re: 55" Vizio XVT553SV Powering off problems

You'll get better help with good pictures.
Could be something as simple as bad solder joints.
Capacitors can be bad but look good.

Unplug the inverters. Does it power on?
Freeze spray the capacitors, does it power on longer?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Thanks for responding. If I unplug the power from either PSU to T-conn board, or ribbon from main board to T-conn board the TV stays on for about 2 minutes (instead of 10 seconds), then powers off in same way. I have to get some freeze spray. Could you look at the pictures & tell me what to unplug for testing?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Can anybody help me?

[Glitcher]

Re: 55" Vizio XVT553SV Powering off problems

When youre watching something and it powers off, does the sound stay on?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

No it doesn't, everything powers off together

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Any help out there? Is this TV repairable? I have a good meter and don't want to throw parts at it, just need a little direction. I know Vizio is not very good, AT ALL! Anyone willing to tackle it?

[Glitcher]

Re: 55" Vizio XVT553SV Powering off problems

Don't know much to go on with these newer types. I would guess either PSU or main board. But since you still have voltages outputted by the psu after it shuts off I would lean towards the main board. Not certain though.

[ecking767]

Re: 55" Vizio XVT553SV Powering off problems

maybe some components are over heating,check the main board cpu and HDMI chip for overheating. touching the heatsink shield should be warm to the touch.


Which input are you using?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Well ok, can anyone help me troubleshoot the main board?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Hi ecking767, I am just plugged in, I dont have a separate input. The CPU is more than warm, it's pretty hot! but when the TV turns of after 10 secs, it's not that hot. The voltages remain after it powers off and the CPU continues to get hotter. I'm not sure which is the HDMI chip

[ecking767]

Re: 55" Vizio XVT553SV Powering off problems

I was asking which input on your TV are you using.

if that heat sink shield is getting extremely hot in 10 second then your CPU could have a short or too much voltage is being applied some where. So disconnect any signal going to the TV. check the caps voltages on your main board. They should range from: 1.2vdc to 12vdc

[Glitcher]

Re: 55" Vizio XVT553SV Powering off problems

I've had this model before and its normal for the cpu to feel hot on the main board.

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

HDMI chip is not hot & CPU is not hot when it powers off, only gets hot after that. I have no inputs to the TV at this point. I checked all caps & all are within voltages you listed except CE39 this one reads 0.013V. This is located just to the right of the ethernet plug in socket. As you look at the picture there are two next to the ethernet socket, it is the top one with no voltage. Also I have 18V on some caps, but I believe this is normal right? As I have 18V on this board normally.

[ecking767]

Re: 55" Vizio XVT553SV Powering off problems

the CPU metal shield show be warm, you should be able to place your finger on the metal shield and its should stay at a warm to the touch. can you confirm this?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Yes it does stay warm

After the TV powers off, I unplug power & leave it for a while then plug the power back in. I have the 5.17V standby everywhere. In this condition when I measure the caps on the main board CE39 now measures 4.81V & 1.107V on ground side, does this sound normal? All other caps are 0.0V on ground side & 0.0V mostly on rest with a couple reading 2.5V & 3.3V

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

OK, now the TV flickered on & off for about 10secs & went off. Now it wont respond to the power button or remote at all. When I plug the power cord in it doesn't even flash the Vizio amber & white any more, it just stays steady amber. I do have 5.17V everywhere on the boards, fuses have not blown. The way I think it works is the 5.17V standby is used to boot up the main board. Does anyone know the steps to measure standby voltage on the main board, after the fuse? The fuse is good, 5.17V on both sides, but where does it go next?

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Solved: Couldn't get any help on this one so I ordered a new main board, plugged it in and now the TV works like it should again. Now that I have narrowed the issue down to the main board, is anyone willing to help me try & find the problem on the board so I can have it for a spare? I hope this helps other Vizio (throwaway-TV) owners, I know it's impossible to find resolved issues online anywhere, everyone seems to give up!

[truep]

Re: 55" Vizio XVT553SV Powering off problems

You could check all the three pin regulators on the main board both when it shuts down.

[Go Cards]

Re: 55" Vizio XVT553SV Powering off problems

Thank you truep. How do I check them & where are they?