How to check for a blown fuse on board.

[wvhandyman]

I have a Samsung HT-Z310 Surround Sound Receiver. This week in a big snowstorm we had some power surges. The surges blew out my Monster Surge Protector that the receiver was plugged into.
Afterwards the receiver would not power up. I have some basic electronics knowledge and I would like to check the fuse and see it it’s blown and if not check the power board and see if that’s what is bad.

Here is the board:

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And what I would guess is the fuse area:

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Is FL1 the fuse? I read "Fuse open check FC1,FC2" do i check resistance between the 2? If the fuse in not bad how best to determine if the board is bad?

Thanks for any imput.

 

[Sceadwian]

Crappy surge protector if it still didn't protect the device it was plugged into =O
You can check the fuse on contiuity mode on a multimeter, but this won't always tell you if it's good, generally you test it with a small light bulb and a battery as you need to pass some current through it to see if it's good or not, fuse testers are typically nothing more than a light bulb connected to a battery that draws a few hundred ma's of current.

 

[wvhandyman]

Is that fuse plugged in or is it soldered in. If its just plugged in could I jump between the plugs and try and power up. If its soldered could I just run a jumper and find the same thing?
If it powers up I can the start looking for a replacement.

 

[Sceadwian]

Unless there's a failure somewhere else in the amplifier that's causing high current draw in which case part of the stereo will go up in smoke.... Only jumper it with another fuse not a straight piece of wire. The markings on the fuse are pretty straiight forward, it's a 3amp 220V fuse, obviously it carries mains power so be careful or you'll go up in smoke, or at least get a healthy zap.

 

[bigal_scorpio]

Unless there's a failure somewhere else in the amplifier that's causing high current draw in which case part of the stereo will go up in smoke.... Only jumper it with another fuse not a straight piece of wire. The markings on the fuse are pretty straiight forward, it's a 3amp 220V fuse, obviously it carries mains power so be careful or you'll go up in smoke, or at least get a healthy zap.

Hi Sceadwian,

Just wondering if you misread the fuse? Looks like 6.3A to me not 3A.

I know smaller fuses are considered safer but too small can have the circuit blow under normal conditions and the OP searching for a non existant fault.

Also in my experience the top cover easily comes off the box fuses and makes testing / bridging much easier.

Al

 

[wvhandyman]

Since this was a power surge that caused this, would the surge in cause the fuse to blow?

 

[Externet]

Hi.
Fuse checking should be measuring continuity between both terminals of CN1 to both terminals of VRL1. If the fuse is open check FC1 and FC2.
If needs replacement, board has to be lifted to desolder. If the fuse is healthy, check if there is any live supply coming out of that board anywhere, as the remote control receiving circuitry should be full time energized. If there is no live DC anywhere, chances are something in that supply board is kaput or is not being commanded to turn on.

If there is AC and DC at the black bridge rectifier pins between the choke marked DY-13M2 C and the lower large black electrolytic capacitor, fuse is fine.
Miguel

 

[wvhandyman]

Ok here is what I did. I just took the board out, 4 screws and 3 plugs. I used the continuity and the resistance settings on my meter and checked between the 2 prongs of the fuse (bottom side or board). I did not get any readings on either setting (meter didn’t move). So I assume the fuse is blown. I’m I missing something or over simplifying here?

Do you think I can just take the board to Radio Shack and ask them to replace the fuse, or get me a solder sucker or blower or what ever its called and do it myself?

 

[Sceadwian]

oops, yeah I did read the fuse wrong, those commas as decimal delineation confuse me sometimes, sorry bout that. Too small should be perfectly fine with an audio amplifier as long as it's not producing powered output. So start it up without speakers connected and use any slow blow fuse over an amp or two. The filter capacitors hopefully won't trip a slow blow fuse.

I wouldn't trust a meter as a fuse reader, fuses generally need to be tested under load, which is why they're typically tested with a couple AA batteries and a simple low voltage light bulb that draws a couple hundred ma.

Radioshack would not touch that with a 10 foot pole. Removing that would require a small roll of solder and a soldering iron, apply a little extra solder to the back of the board where the fuse leads are, then heat both solder blobs up at the same time while pulling on the fuse from the other side of the board with a pair of plyers. You could try a solder sucker or solder wick but personally I have really bad luck with the stuff.

Something doesn't feel right about that fuse as it's definitly not a typical fuse form factor, they're usually long glass tubes so I'm not sure if there's anything specific about it that might be important. It's just odd because primary protection fuses should be designed to be easily replaced.

 

[wvhandyman]

If the fuse wasn't blown shouldn't the ohm meter given me somekind of reading?

If a replacement fuse can not be found could I just replace it with a glass tube type fuse holder. soldering each lead into the board holes. (or do they make a fuse holder with that small wire?)

 

[Sceadwian]

Not necessarily. Depends on the exact fuse construction, this is why they're always tested under load. A bad fuse can produce a positive continuity test on a meter without a load, and a good fuse can produce a high impedance value without a load.

If it is the fuse you could use solid wire to a fuse clips, just make sure you use electrical tape or otherwise isolate it from the chance of it bumping into anything else, it's live AC after all.

 

[wvhandyman]

Ok, I tore apart my mag-light, wired the batteries in series and ran the circuit thru the fuse (no current) So am I convinced its the fuse?

 

[Sceadwian]

hehe, you're convinced it's the fuse with a question mark <chuckle>
Sounds like the fuse to me, but I'm not even 100% sure that is a fuse, it just doesn't look like fuses I usually see. I'm surprised no other users here have chimed in on exactly what it is, but until someone else confirms the component I don't want to commit myself to saying it's the problem or that shorting it won't result in an even worse overall meltdown or problem.

 

[Birdman Adam]

Am I just seeing things or is this cap popped?

**broken link removed**

 

[wvhandyman]

No its not popped it was just leaning to one side.
How about it guys is FL1 in the second picture a fuse?

 

[Sceadwian]

I'm leaning towards no, as you said the black text there reads FC1 and FC2 to check fuse... Doesn't mention FL anywhere.

 

[Birdman Adam]

Just found it online by searching "382 Fuse":

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So the one you need to replace with is this one:

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And here he is on Mouser for $0.48:

Fuses 250V IEC TL LL 6.3A TR5

Oh and I'm guessing FC1 and FC2 are the two leads on the fuse?

I dont know what kind of surge protector you were using but I would never rely on one of those cheap ones:

**broken link removed**

 

[Sceadwian]

Yeahhh. Hail birdman =) So I guess you can go ahead with the glass fuse as a jumper to check see if it powers up. If it does then you even have the right exact component to replace it with.
And you know never to buy a surge protector power strip from that company again =O Either that or there was something seriously wrong with your grounding connections in the first place.

 

[wvhandyman]

FC1 is the black round (Capacitor?) and FC2 is one leg of the power cord plug.

I was using a Monster Cable Surge Protector Which I thought were good surge protectors. I had a bunch of stuff plugged into it and this is the only thing damaged.

 

[wvhandyman]

Guys I sure appreciate everything. I feel like i accomplished and learned something today. I'll chase some parts down tomorrow and let you know how things come out.
THANKS!