Looking for help from anyone handy with circuit boards/EEs

[nevets88]

This is a photo of my ISP's battery backup unit circuit board for the ONT. I'm tired of replacing the battery, having purchased several from the ISP,  the officially sanctioned battery did not last anywhere near the stated duration. 

I want to destroy the buzzer, which goes off every 15 minutes because the battery is almost dead. I followed the directions to disable/silence it, doesn't work.

If I understand correctly, it's the black cylinder shaped thing with the plus sign at 12 o'clock. It's flush to the board, so it's not like I can snip the legs attaching it to the board. And I don't want to fill it with glue or whatever, that's not going to silence it.

How would you remove it? I could gently try and rip it out with a pair of pliers, but looking for a more elegant way, if possible.

 

[BamaWade]

If you're able to easily remove the board from the casing, your best option IMO is to do that, then desolder the buzzer's contact points from the back and pull it from the board.  Of course, make sure no power/battery is connected.  I'd test via the power button once ready to work...most you should get is an LED blink (if that) from the discharge of any stored charge in the board's components.  Even then, I'd be doubly careful on the desolder to not create a short.

Not an EE, but a ~20 year IT guy with some component level experience.

BamaWade

Edited October 4, 2016 by BamaWade

[drmevo]

If it belongs to your ISP, why won't they fix it? If you pay an equipment fee every month they should. Furthermore, if you end up bricking the thing by accident are you sure you won't be on the hook with them to pay a (probably outrageous) replacement fee?

if you own the device and don't mind taking the risk, then I would do as @BamaWade suggested. But I'm also an IT guy, not an EE.

[nevets88]

7 minutes ago, BamaWade said:

If you're able to easily remove the board from the casing, your best option IMO is to do that, then desolder the buzzer's contact points from the back and pull it from the board.  Of course, make sure no power/battery is connected.  I'd test via the power button once ready to work...most you should get is an LED blink (if that) from the discharge of any stored charge in the board's components.  Even then, I'd be doubly careful on the desolder to not create a short.

Not an EE, but a ~20 year IT guy with some component level experience.

BamaWade

Thanks. I'm not very good at soldering as I've only ever soldered vs desoldering. If I can pull the board out, I'll find some junk boards to practice desoldering.

2 minutes ago, drmevo said:

If it belongs to your ISP, why won't they fix it? If you pay an equipment fee every month they should. Furthermore, if you end up bricking the thing by accident are you sure you won't be on the hook with them to pay a (probably outrageous) replacement fee?

if you own the device and don't mind taking the risk, then I would do as @BamaWade suggested. But I'm also an IT guy, not an EE.

It's technically not broken, and I don't want to spend time on the phone and whatever else with them to prove that the battery didn't last its allotted time, willing to take the chance to destroy this stupid f*@ing bloody buzzer.

[drmevo]

3 minutes ago, nevets88 said:

Thanks. I'm not very good at soldering as I've only ever soldered vs desoldering. If I can pull the board out, I'll find some junk boards to practice desoldering.

It's technically not broken, and I don't want to spend time on the phone and whatever else with them to prove that the battery didn't last its allotted time, willing to take the chance to destroy this stupid f*@ing bloody buzzer.

Is the BBU built-in to the ONT? If so, it's usually pretty easy to get whatever the upgraded version of the ONT is, for free (of course it depends on the ISP).  But, I understand the need to rip the thing apart 

[nevets88]

20 minutes ago, drmevo said:

Is the BBU built-in to the ONT? If so, it's usually pretty easy to get whatever the upgraded version of the ONT is, for free (of course it depends on the ISP).  But, I understand the need to rip the thing apart 

Unfortunately, the ONT is separate as it's outdoors.

I had another unit which was all indoor, the ONT was separate as well, but all you had to do was remove the battery from the BBU and it never beeped again - you didn't have any power outage backup, but these manufacturers, they kill you with this beeping that you don't care if you don't have any power outage backup, btw, it's only for the phone, no internet backup. 

Removing the battery from BBU with this one, it still beeps.

[Club Rat]

50 minutes ago, nevets88 said:

this stupid f*@ing bloody buzzer.

In your photo, the part you are describing as a buzzer has "part numbers" stamped on it.

Post a better pic, or google the part.

If you can identify the part, it may open other options such as removing the ground or power leg by only de-soldering the source or another manner.

It would also verify your seeking the correct solution.

[mchepp]

To know how to properly desolder it we would need a picture of the back. Likely a thru hole soldering but would be good to see the back to be sure. There are some big capacitors there be sure the power is off and stay away from the caps. I have caught hell from caps that are smaller than those.

[dennyjones]

Without a schematic drawing,  it's hard to say if the buzzer circuitry is tied to something significant.  Best bet, take your medicine, gather some patience and call.  If it is disposable, take some solder wick and try to clean the solder from the leads to remove the buzzer.  Don't use excessive heat. 

Ensure you are grounded when you touch the board.  ESD is real and can damage circuit boards easily.