Creative Speaker Repaired For Continuous Humming Noise
Received again this set of Creative home theater speakers for continuous humming noise. On testing found Humming start directly on power ON the Unit without connecting it to any device (Stereo Pin is not connected) and without satellite speakers. It indicates problem with the woofer circuit….
So for testing I removed the amplifier circuit out.
I did thorough Visual Inspection because as I already mentioned in my previous article that PCB Is degraded & some traces are also out of Mica base.
Connected two Satellite speakers to identify any change in working, but same problem. checked Bass control POT by replacing another still same problem. checked by replacing mains filter capacitor still same problem, checked components for overheating; found metal heat sink is hot. (not sure about normal heating) …
Suspected Main IC because it is directly attached on metal heatsink.
Now to arrange this IC for replacement, I googled for availability…. as usual price is very high 75% cost of the new speakers. I made my mind to conclude the repair & return the unit to the customer….
While putting back the PCB inside the speaker box; I questioned myself am I missing something????….
Yes ……I did not checked woofer itself.
I removed woofer from the box for testing.
On testing I found woofer coil is showing 0.7 Ohm instead of 4Ohm….
I did not suspect this woofer. I arranged one 10W Woofer from my salvaged parts.
But to my bad luck this woofer coil is showing open circuit ……
So I decided why not to give original woofer for repair.
So contacted my nearby Part suppler & discussed about full Speaker Reconing…he advised me first he will try to change the coil only, because Cone look good but while in changing process if cone is tear off full Reconing is needs to be done. I sent the woofer for repair. I got this woofer back after successful Reconing.
Connected this woofer on the Circuit now there is no humming noise…. Problem solved. Re assembled the unit & it is ready to pick up……
This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.
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Note: You can check his previous repair articles on Digital Audio Player Repaired