M50W repair thread

[wwenze]

Finding replacement 3.5mm socket is usually hard, for best compatibility you should desolder it and visit SLT.

Or you can use the RCA in.

 

[noogiehead]

Hi All,

I just had an issue with my M50W very similar to what has been posted here about no bass from the subwoofer but power to the speakers and volume power & control.

So I opened up the back plate but cannot find the 2 fuses mentioned by wwenze. It seems the board has been updated to a newer version, anyone know where they placed the fuses? They are not easily visible to me.

i.imgur.com/DS3tCi2 .jpg

Sorry for the link, I can't post images just yet.

thanks

 

[wwenze]

Sometimes the fuse can be on the wires from the transformer, in a fuse holder like this

 

[noogiehead]

Sometimes the fuse can be on the wires from the transformer, in a fuse holder like this

I found that fuse, but it seems okay, I'll still go ahead and change it. Out of curiosity, wouldn't that fuse cause the entire power supply to stop? I'm still getting power to my volume control and my speakers.

 

[wwenze]

If the fuse is still good there is no reason to change it. The capacitors still look good too. The fault may not be in the power supply. Sometimes it can be the connectors. Worst case, disconnect the subwoofer and measure the resistance of the subwoofer, you should be seeing something between 1 to 10 ohms for a working one.

The rest of the steps would be standard troubleshooting - Check if you have the correct DC voltages on the output of the power supply board, check if the voltages are reaching the amp chips. Check if input signals are reaching the amp chips. Then just trace until where the break occurs.

I found that fuse, but it seems okay, I'll still go ahead and change it. Out of curiosity, wouldn't that fuse cause the entire power supply to stop? I'm still getting power to my volume control and my speakers.

There are two separate power supplies (transformer winding + rectifier + capacitor). The higher voltage one supplies only the subwoofer amp, the lower voltage one supplies the satellite amp, and the volume control + power switch taps power from this one also.

 

[dreamwalkz]

Hi Wwenze, my m50w woofer has a constant crackling sound when powered on, any idea how to fix it?

Will upload the soind of it when I'm home.

here's video of it.
https://streamable.com/ykbfq

 

[wwenze]

A bit hard to tell tbh without some basic troubleshooting...

Nothing connected and 50Hz buzz coming from subwoofer = first thing i suspect is dead capacitors but can also be amplifier.

Considering M50W's track record so far, dead capacitors are likely.

If you play music and it still works (other than the fact that it still buzzes), then is very likely capacitors. The buzz gets louder with age.

 

[ckboyz]

master wwenze, my left speak M50W does not have any sound. No idea why, do know you who can repair or do you prefer any repair service?

 

[wwenze]

Try Sigma (AV) Service, call them and check if they can fix.

 

[mirage_77]

Hijack this thread awhile as seems to have alot M50W users here.

Have being using this set of speakers for 4-5 years. Great performance.

But recently when I googled this set, some of the back-view of this subwoofer seems to have an ethernet port amongst others (mine only have the basic L/R, controller port etc).

If there two different versions; Or our local only brought in the more basic one?

 

[wwenze]

Could it be M80W you saw?

 

[mirage_77]

Could it be M80W you saw?

https://www.lazada.sg/products/hivi-swanspeakers-m50w-mkii-21-multimedia-speakers-i3454565.html

As above. Is this an upgraded model? Seems to have Wifi and optical inputs.

 

[wwenze]

Is this an upgraded model?

It does say MKII at the back...

 

[suchaloser]

Okay, need help/advise on M50W.

No power to the subwoofer/control module. Replaced the fuse (2A) at the transformer end, still blow when I turn it on. There's a "boom" sound from the speakers.

What would be the next step? Try a higher fuse?

 

[wwenze]

The treble part and the bass part each have their own fuse (on the PCB), the fuse on the transformer should be the primary side. Can you remove the fuses on the PCB / remove the connectors from transformer to PCB and see if it still blows?

 

[suchaloser]

Thanks for your response. If I get it right, I’d remove the 2 fuses on the PCB and connectors from Transformer to PCB. This is to test if the PCB is working? The fuses on PCB is glued. How do you suggest to remove it?

 

[wwenze]

Removal of the fuses is just to see whether the transformer fuse still blows. Do not operate the board without fuse by shorting in place of a fuse.

It's glued but the glue is not necessary for electrical nor mechanical connection in the fuse holder, so just take it out.

 

[suchaloser]

Removal of the fuses is just to see whether the transformer fuse still blows. Do not operate the board without fuse by shorting in place of a fuse.

It's glued but the glue is not necessary for electrical nor mechanical connection in the fuse holder, so just take it out.

Noted on that. I don’t get what you mean by “operate the board without fuse by shorting in place of a fuse”

I see. Oh my question was how do you physically remove the glue (hot gun?) that’s holding down the fuses.

 

[wwenze]

Just pull it out. The glue is not hard.

 

[jimmyacid]

Hi everyone, is my M50 still salvageable?
The subwoofer give this scary cracking trumbling sound when ever the bass kick in. The louder the volume and lower the bass the scarier it is. it's like going to burst if the volume is higher. Thanks

https://streamable.com/ndmihy