Repair damaged studio monitor (M-Audio BX5a) - broken XLR circuit board connector

rdarwish

New member
Hello,
I am fairly new to home recording, and, like many of you, light on liquid assets at the moment, and am hoping that someone smarter than I can lend me some advice as to how to proceed with a broken studio monitor.

Said monitor (Bx5a), was accidentally knocked over while plugged in (but off) with a TRS 1/4" cable. The speaker turns on (the LED turns on) and I can hear faint static coming from the speaker, but no connector (it can take 1/4" or XLR) produces any sound. I have tried different cables and connectors, and the other monitor is just fine. It must have landed with the 1/4" cable down, because the back panel is dented in around the connector inputs.

Since it is out of warranty, I decided to open it up to see if anything was obvious. The plastic housing that the 1/4" cable goes into is cracked and separated from the back panel (it was glued), and the prongs coming off of the XLR connector seem to have snapped.

My first thought was that the prongs were separate parts sticking out of the circuit board, and I attempted (poorly, don't laugh) to solder the prongs to the back of the XLR connector with no luck. After trying this, and realizing it wasn't helping, I then speculated that the prongs had originally been actually part of the XLR connector as in they jutted out the back of the part and were bent and soldered to the board all as one object. I hope that makes sense.

I do believe that this thought is correct, but I don't know what is the best course of action. Like I said, money is an issue right now, so if there is a DIY solution, I would prefer that over professional repair (second choice) or replacement (a distant third, as these monitors have gotten very little use).

I tried to take pictures, but I'm not sure they are very helpful. Also, on many forums, people are saying that these speakers are notorious for bad capacitors, which I think I may have as well, but I don't want to start chasing a red herring. Like others with the capacitor problem, I am (now) getting a hiss, and I did hear a loud *thump* when turning it on, but I had thought that was normal.

My gut tells me that the monitor is fine aside from the connector issues, but I have nothing to base that on except for ignorance and hope.


Any help would be appreciated.

BX5a-1.jpgBX5a-3.jpgBX5a-2.jpg
 
what you do is open the other monitor and compare, cos at least you can be certain what's normal.

The cap you've pointed out is domed so i'd be replacing that, but make sure the xlr socket is fixed (same as the other monitor) before you power on again.

What is that burn mark in the bottom pic near the J in jack?

Is all that brown crap just glue or has something else burned out?
 
Thanks. That crap is glue or something. It's all over the place. I will change the cap, but do you have any ideas about fixing the XLR connector? I can't find one online that includes those prongs coming out the back. I think they are made from gold.

Thanks again.
 
If you've tried soldering it and it didn't work out, perhaps you could buy a standard xlr connector and completely remove all prongs from the board.

This would allow you to just solder three wires to the board, and join them to your new connector.
 
Thanks for the suggestion about opening up the other one. I did that, and it seems the damage to the XLR connector is pretty bad. Not only are those prongs connected to the XLR connector, but there is a prong that should be connected to ground, but is missing. I bet it fell out when I opened the broken one and it just looked like nothing to me, so I ignored it or something.

So if I understand you correctly, I can just use ANY wire (i.e. not gold or anything fancy) to connect the new XLR connector to the board?

I found the part number for the XLR connector used in this speaker, and found a million of them online, but none had those long prongs attached. I'm hoping I''m understanding you and I don't have to worry about that.

Thanks again for helping out an ignoramus.:o
 
Thanks for the suggestion about opening up the other one. I did that, and it seems the damage to the XLR connector is pretty bad. Not only are those prongs connected to the XLR connector, but there is a prong that should be connected to ground, but is missing. I bet it fell out when I opened the broken one and it just looked like nothing to me, so I ignored it or something.

So if I understand you correctly, I can just use ANY wire (i.e. not gold or anything fancy) to connect the new XLR connector to the board?

I found the part number for the XLR connector used in this speaker, and found a million of them online, but none had those long prongs attached. I'm hoping I''m understanding you and I don't have to worry about that.

Thanks again for helping out an ignoramus.:o
yes ..... any wire will do. Those prongs are just conductors and it doesn't matter if it's those or a wire.
 
no probs.
any wire will do. It's a line level input, so some patch cable inner cores or the like will be fine.

If there's a bit 'missing' make sure it didn't fall in somewhere that it could cause a short.
 
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