Mordaunt Short ms309w Thunder rumble Repair attempt

Blacksubaru

Novice Member
Hi all, I am a newbie on avforums, I have found some good advice on this forum regarding my Mordaunt Short Ms309w.
I bought this Sub on ebay from someone who said it was all working fine etc just a little dusty etc........ I picked it up quite late at night so i did the ultimate wrong thing and did not test it with the seller and drove 100 miles home with the sub and when i got home the sub had no power 😫.
So i checked the fuse above the kettle power lead socket at the back of the sub and it had blown so i changed it and i had power, then i placed and input and had sound (what a room shaker that ms309w is) but after about 10 mins i started to hear a constant thunder like rumble noise which got louder with the volume and was present even without input. So done some research and turns out its those 2 x 10uf 100v Bi Polar capacitors on the small pcb inside. I will be attempting to repair this myself as i enjoy this kind of thing as im a plumber/electrician by trade so solder and wires isnt strange to me lol.
I will be uploading my step by steps incase anybody wants to try themself or has the same problem. Wish me luck

I bought the capacitors from RS Components at around £1.24 for 5 with free delivery (Bargain😎)
20191008_210824.jpg
20191008_210804.jpg
20191008_210713.jpg
20191008_210645.jpg
20191008_210824.jpg
20191008_210804.jpg
20191008_210713.jpg
20191008_210645.jpg
15705757472181277139152001705353.jpg
 

Blacksubaru

Novice Member
So i replaced the 2 10uf 100v caps and the issue was still there and found another issue with the power relay, it kept switching on and of and blowing fuse so i cut the black insulation surround off to reveal relay and it was discolured from heat on a small section of relay
20191011_000253.jpg
20191011_000253.jpg
 

Attachments

Top Bottom