Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

Maybe it is indeed a 15amp just to handle the surge. Does it still work with the atc fuse?

Yes it does work with the ATC fuse, it's a 3A rated fuse

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

Maybe it is indeed a 15amp just to handle the surge. Does it still work with the atc fuse?

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I bet the fuse should have been a slow blow fuse and your fuse you put in it was a fast blow fuse. Which is why it blew straight away!

You may be right. I need to see if I can find the right fuse for it.

[cheeky2]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I bet the fuse should have been a slow blow fuse and your fuse you put in it was a fast blow fuse. Which is why it blew straight away!

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

The voltage rating is not that important in this case. The voltage rating has more to do with the distance between the contacts. an atc fuse would not be good in a 120v circuit, If the fuse opened it might continue to arc across the open fuse element.
I would just replace it with a 3~5 amp smd fuse that will mount to the pads.

Ok so I found a fuse from a t-con board with the markings "YD". The rating printed on the board was 32V 5A. I removed it from the t-con, installed it on my main board, checked it for continuity after the install and it checked good. I installed the main board, plugged it in, turned the TV on and the fuse blew straightaway. Looks like the Main Board has a problem. Now for where to start?

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

The voltage rating is not that important in this case. The voltage rating has more to do with the distance between the contacts. an atc fuse would not be good in a 120v circuit, If the fuse opened it might continue to arc across the open fuse element.
I would just replace it with a 3~5 amp smd fuse that will mount to the pads.

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

8 hours run time and the backlights are still on.

I'm still looking to find out if the current rating on the automotive fuse is 3A at 24V. Anyone? And I meant ATC type fuse in my previous post, not AGC type.

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I would install something like a 3~5 amp pigtail fuse in that position and see what happens. The short may not be on the fuse but the circuit that runs off that supply may be loading it down.
Like I said, based on the power supply rating I can't see it being a 15 amp fuse.

The three makers R_J references all have different size fuses, you should be able to determine the maker with a micrometer.

So after returning from physical therapy this evening I cracked open the TV, piggyback soldered a low current automotive AGC type fuse holder to each end of the fuse and installed a 3A AGC type fuse, all from my auto parts collection. I have plenty of car stuff since before repairing TVs I was a Master Auto Technician and an I-Car certified collision repair/body and paint technician. Currently the TV now has backlights and is in operation in my kitchen. It's been on for 20 minutes.

There's just one question before I temporarily put the back on it for testing. Since cars are a 12 volt system and this circuit is 24 volt, should I have installed a different rating fuse? I'm thinking it should be ok but I wanted to ask, just in case.

[diif]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

The three makers R_J references all have different size fuses, you should be able to determine the maker with a micrometer.

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I would install something like a 3~5 amp pigtail fuse in that position and see what happens. The short may not be on the fuse but the circuit that runs off that supply may be loading it down.
Like I said, based on the power supply rating I can't see it being a 15 amp fuse.

I can't see it being 15A either, and that's a good idea to solder in that fuse. I believe I will try that. Good call R_J!

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I would install something like a 3~5 amp pigtail fuse in that position and see what happens. The short may not be on the fuse but the circuit that runs off that supply may be loading it down.
Like I said, based on the power supply rating I can't see it being a 15 amp fuse.

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I looked at the images on google It seems to resemble this type.
If you look at F3201 [T] 5Amp. I would say that is a different maker.

Yes, I agree F3201 looks different, and I can see why you say that.

If indeed F4501 is 15A that makes me question something else:

That's a high current fuse, and with no short found off the output side of it, what else could make such a high current fuse go open? It seems to me there would have to be a problem in the backlights themselves, or an intermittent short in one/some of the board components? What do you think?

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I looked at the images on google It seems to resemble this type.
If you look at F3201 [T] 5Amp. I would say that is a different maker.

The letter Y is not used on all series of smd fuses
Without the schematic it is just a good guess

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

Just by looking at the one in the picture it does look like a solidmatrix type

R_J, how are you able to tell they are the manufacturer of this fuse? Is there something about its construction or appearance that gives it away?

Like they say, there's no substitute for experience, and you have way more than me!

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

How does someone tell which one it is? Is the manufacturer name on the fuse somewhere?

Just by looking at the one in the picture it does look like a solidmatrix type

It seems to be on the 24v supply and the power supply can only supply 24v/3.91Amps

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

If it is a Matsuo KAH series, (Y) would be 2.5 amp
Bourns SinglFuse™ SF-0603F Series (Y) would be 5 amp
Solidmatrix HA 1206 series (Y) would be 15 amp

How does someone tell which one it is? Is the manufacturer name on the fuse somewhere?

[R_J]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

If it is a Matsuo KAH series, (Y) would be 2.5 amp
Bourns SinglFuse™ SF-0603F Series (Y) would be 5 amp
Solidmatrix HA 1206 series (Y) would be 15 amp

[diif]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I tried a google search for "SMD fuse identification chart" but didn't find anything. I even called Mouser...they couldn't help either.

I Used "SMD fuse rating" in duckduckgo, it finds a document from Digikey, it's 15A.
Using SMD fuse identification chart in Google, you should have tried images, it shows you what you want.

[DXseekerMO]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I'll be damed if I know but I did run across this: https://www.google.com/search?client...inboard%2Bfuse

I tried a google search for "SMD fuse identification chart" but didn't find anything. I even called Mouser...they couldn't help either.

[nomoresonys]

Re: Vizio D55-f2 backlight/power supply 20v/24v rail output high 26v

I'll be damed if I know but I did run across this: https://www.google.com/search?client...inboard%2Bfuse