Author Topic: Reparing an active monitor  (Read 263 times)

0 Members and 1 Guest are viewing this topic.

Offline stdcallTopic starter

  • Newbie
  • Posts: 8
  • Country: il
Reparing an active monitor
« on: August 06, 2024, 07:11:31 pm »
Hi.
I'm trying to repair my M-Audio BX8 active studio monitor.
It had one bad cap (c56) and I replaced it, and by mistake I connected it reversed.
After powring on, the cap exploded. I removed it and placed a new cap properly. but I can't hear anything no longer.
I tested the CAP and it measured +32VDC. I also tested the other big cap (c53) and it measured 18VDC.
I assume the power circuit is okay. where should I check next ? do you have pointers what should I check ?

Schematics I found on the web are attached.

Thanks ! Ramon
 

Offline Gyro

  • Super Contributor
  • ***
  • Posts: 10083
  • Country: gb
Re: Reparing an active monitor
« Reply #1 on: August 06, 2024, 07:51:26 pm »
There are other voltage rails that you need to check before you can say that the power circuit is ok. C53 is on a completely different power supply section from C56. You need to check all supply rails - it could be that C56 exploding has shorted Q21 and pushed the +15V rail up to +32V. There may have been some knock-on effect on the -32V or -15V rails. You need to go round all supply rails methodically before you can move on to see what else might have been damaged.


P.S. Disconnect the speaker units until you have done basic testing to avoid the risk of burning them out.
« Last Edit: August 06, 2024, 07:55:32 pm by Gyro »
Best Regards, Chris
 

Offline wraper

  • Supporter
  • ****
  • Posts: 17820
  • Country: lv
Re: Reparing an active monitor
« Reply #2 on: August 06, 2024, 07:56:58 pm »
You should check if electrolyte from the blown cap did not get onto electronics.
 
The following users thanked this post: Gyro


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf