Hello gurus,
I got this malfunctioning active subwoofer from a guy, who says he gave it too much power and probably burn it (didn't say what exactly was done and his electronics knowledge seems to be None).
I would like to get it back to life, to serve me as his new master (I mean...the subwoofer)
Need your advice to troubleshoot the sub's circuits - would appreciate your help on this.
It does power on - there's a Green led on, however it doesn't produce any sound (if 'HighLevel Out' speakers are connected - they do produce a sound)
After I opened up the sub
- I measured 5.4 Ohms on a speaker/driver. I connected some old woofer I had laying around - it also didn't produce any sound
- the transformer is functioning (in 220V, out 2X 21.4V)
I see 2 suspicious points:
1. the missing Q5 on the 'heatsink PCB' (can be seen on a pic) - looks like it had some thermal issues - WDYT about that ?
2. The 'white block' - a cement resistor - has some brown paste on it's base - I guess it's not kind a 'leakage' , am I right ?
Thanks in advance.
I got this malfunctioning active subwoofer from a guy, who says he gave it too much power and probably burn it (didn't say what exactly was done and his electronics knowledge seems to be None).
I would like to get it back to life, to serve me as his new master (I mean...the subwoofer)
Need your advice to troubleshoot the sub's circuits - would appreciate your help on this.
It does power on - there's a Green led on, however it doesn't produce any sound (if 'HighLevel Out' speakers are connected - they do produce a sound)
After I opened up the sub
- I measured 5.4 Ohms on a speaker/driver. I connected some old woofer I had laying around - it also didn't produce any sound
- the transformer is functioning (in 220V, out 2X 21.4V)
2 PCBs are inside (One screwed to the heatsink and another is kind of glued to the back panel - that has a Phase switch and knobs) | The PCB that's screwed to a heatsink: |
I see 2 suspicious points:
1. the missing Q5 on the 'heatsink PCB' (can be seen on a pic) - looks like it had some thermal issues - WDYT about that ?
2. The 'white block' - a cement resistor - has some brown paste on it's base - I guess it's not kind a 'leakage' , am I right ?
Thanks in advance.