tracking down a blown fuse for a sub woofer

[silverdale]

I have an old Sony SA-WP890 sub woofer and after checking a small internal fuse has blown. I'm trying to track down the correct replacement It says on it T1AL250VP , I can find plenty of T1AL250V so I'm wondering, what is the difference between V and VP fuses and does it make a difference ?.

 

[Rumpelstiltskin.]

http://teakdoor.com/computer-news/102226-time-delay-fuse.html

 

[silverdale]

thanks for that, before I posted up I went in live chat at RS and the said they didn't do them. I found one place that want's a fiver and the only other was China wait a month.


I found this just this minute ;-

"A 250VP fuse can handle a pulsating electrical current. A regular 250V fuse will break when it receives a sudden surge of electricity."

So I'm a bit reluctant to use anything other than what came out incase I screw it up

 

[Rumpelstiltskin.]

The "L" following the "A" of the Amperage rating usually refers to the Breaking Capacity

L = Low (glass)
H = High (ceramic)
E = Enhanced (glass)

I believe the "P" at the end refers to Lead-free construction

MPS-2 blowing fuses?

 

[silverdale]

ah right so TL1A250V (without the P) will be fine ?

 

[Rumpelstiltskin.]

Appears so, and can be had cheap on ebay

- - - Updated - - -

Fuse 5x20mm Slow Blow GLASS BODY Multi-Variation Listings | eBay

 

[silverdale]

nice one thanks

 

[IANB]

A t1a will be fine mate also referred to as slowblow by some. Maplins will have them cheap as chips mate. But the real issue is Why did the fuse blow?

 

[silverdale]

Not sure why it blew, I've had it a good few years say 6-8 and it's not been hammered. I have looked inside and I can't see anything untoward like caps blown or anything.

I'll replace see how it goes. It's a monster of a thing but without it music & movie night ain't the same without the bottom end. It reminds me of a p*ss poor cam-avi from years ago, all top end

 

[silverdale]

It's looking like there's a fault of some sort. I replaced the internal fuse and dropped the back cover on.
When I plugged it in the was a silent flash of light I could see it through the vents and the new fuse was blown.

I'm not into playing around with power supplies , I'll have to take it in somewhere let them have a look.

 

[chookey]

You have a short somewhere. The circuit isn't over complicated and if you have a multimeter you can do a few tests yourself.
The nature of the fault would suggest that the problem lies within the rectifier stages or possibly shorted turns on the power transformer. The latter could be bad news as the transformer may be difficult to obtain or may be costly.
All the components in the rectifier stages with the exception of R403/R404 can go short circuit. If you test it you will have to unplug the connector to the transformer board before taking readings

 

[silverdale]

I'm not too clever on stuff like this but fine desoldering replacing anything. If I took a picture could you use MS paint and show me were to check ?.
thanks for the help

 

[silverdale]

 

[chookey]

Wasn't able to use your picture siverdale. 2 caps weren't visible in it. To test properly you will need to remove the mainboard and use this layout.

 

[silverdale]

here's a better picture from the underside of the mobo and a view from the top. The large caps in picture one are on the right hand side

 

[chookey]

I marked the components to test for a short on the layout silverdale, it's the same as your underside photo.

 

[silverdale]

thanks for the help, I have checked all the capacitors with a cap meter and their fine and traces with a multimeter. I'm no electronics engineer I only know the basics so I think it's time to let someone who knows what their doing to take a look as it's way over my head , thanks again

 

[chemicalpollo]

Hi,
did you fix it?
I have the same problem but I can`t see photos yet...

 

[silverdale]

No sorry, I ended up buying a new sub woofer

 

[silverdale]

To be honest, the place I took it to I'm not sure if they actually looked at it and just charged me £15 I think to tell me it's knackered. It might be fixable but I wasn't throwing anymore money at it