Vizio VL470M power supply pulsing

[mcross]

I am trying to find the cause of a power supply pulsing. SB is good, but 12 volt goes from around 9-13 volts. sb power light pulses when attached to tv also., Found a blowed (sm) fuse on main board. Set was total dead before that.

[mcross]

Re: Vizio VL470M power supply pulsing

For got the pic

[tom66]

Re: Vizio VL470M power supply pulsing

This can be caused by a bad startup capacitor, the small caps on the primary of the power supply. Since they are very cheap (5-10 cents each), they are often replace without testing parts.

[mcross]

Re: Vizio VL470M power supply pulsing

Thanks Tom, did find a 10uf 50 v, did the trick, now have 2 on the main board , both bad same caps, recaping them now
Mike

[tom66]

Re: Vizio VL470M power supply pulsing

Thanks Tom, did find a 10uf 50 v, did the trick, now have 2 on the main board , both bad same caps, recaping them now
Mike

Did it fix it? The 10uF will often measure high in ESR but the most common failure is a drop in capacitance for the small ones.

[mcross]

Re: Vizio VL470M power supply pulsing

Fixed the ps, but main has an problem, as when i hook up the ps and try to power on, same thing , visio logo flashes.
Mike

[tom66]

Re: Vizio VL470M power supply pulsing

Fixed the ps, but main has an problem, as when i hook up the ps and try to power on, same thing , visio logo flashes.
Mike

So this TV has had multiple problems? That's rare, unless it was a victim of a power surge.

Have you checked all the LDO regulators on the main board?

[mcross]

Re: Vizio VL470M power supply pulsing

Sorry, had to go the other day, No i have not , will check them today and let you know what i find
mike