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#1 |
New Member
Join Date: Jul 2019
City & State: Washington DC area
My Country: United States
I'm a: Knowledge Seeker
Posts: 3
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![]() Hello, like to begin with that I'm a complete novice but I've managed to follow certain videos online to help me fix this but I am now stuck.
The subwoofer is the Bose PS28 III. Using this youtube video (https://www.youtube.com/watch?v=s9GarjV3zzs) I have managed to diagnose with a multi-meter that the issue may be coming from the power supply board (PN: 286612-002) An older thread on this forum (https://www.badcaps.net/forum/showthread.php?t=65417) helped me find the schematics for the issue (although to be frank, I personally, have no idea what to do with that.) I am able to follow the youtube video all the way until the 3:04 mark in the video (when the person starts to diagnose what specific components are shortened/blown in his board). I understand this is going to be different for everyone, however, my issue is that unlike the video (which seems to have very obviously identifiable issues), I am unable to find any blatant issues with the power supply board I'm working with. I'm hoping someone here can look at these pictures I've provided and help me see the obvious. Photo album - https://imgur.com/a/0fjIG7v Thank you! Edit: I've noticed the images didn't upload in full res. I'll update soon with better photos. Last edited by BlueVelvet; 07-09-2019 at 10:51 AM.. |
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#2 |
New Member
Join Date: Jul 2019
City & State: Washington DC area
My Country: United States
I'm a: Knowledge Seeker
Posts: 3
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![]() Here are better photos.
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#3 |
New Member
Join Date: Jun 2018
City & State: Pembroke Pines
My Country: United States
I'm a: Knowledge Seeker
Posts: 1
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![]() Check these components. Inside the circle marked in yellow in the image.
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#4 |
master hoarder
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 10,162
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![]() Could you describe what issue(s) you're having with your subwoofer?
I think that might help us narrow it down where to look. The issue in the Youtube video you linked shows a blown amplifier power supply, which was repaired by changing the primary-side MOSFETs, MOSFET drive circuits, and PWM IC. |
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#5 |
Great Sage 齊天大聖
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 24,065
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![]() nice design, wouldnt want c117 & c118 getting cold in the wintertime!
/sarc |
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