Fire Alarm Panel Surge

So I’ve managed to steal the bridge Rectifier from my 4010 panel since it kicked the bucket a couple of days ago. I heard a pop and all my IDNet devices went missing, Signal cards, and External N2 troubles started blaring. I’ve smelled a burning/melting plastic type smell near the SLC terminals but couldn’t find any burn marks. So I’ve trashed the Sfio board and may or may not replace it in the future. This is not my issue right now.

My problem right now is I’ve managed to get my FS-250 running with the 4010 bridge rectifier and all seemed well and good. The only problem is I didn’t have the connector to J4 (Bridge Rect. Connection) so I wound the wires around the appropriate pin and that seemed to work at first. So I decided to fit it in my 4010 cabinet the best I could. I went to power it on and, for the first couple of seconds all the lights came on like normal then a I heard a huge whoosh and 60hz buzz that sounded like it was vibrating the metal and then the panel died. When I tried to apply power again, I heard nothing, no buzz or lights, it’s like no power is coming in at all. This leads me to believe I might’ve blown the fuse. I’ve tested the fuse with an ohm meter and got no reading what so ever so I believe the fuse is dead? I’m not sure if any other components got damaged as well?

I believe what happened is a strand of wire from the AC lead to the bridge rectifier was touching a strand of wire which brings DC power into the panel. This might’ve got mixed and blew the fuse? My fear is everything on the motherboard, cards and transformers connected to it are dead? Can’t tell for sure unless I buy a new FS-MB2. Is it most likely the fuse or should everything be trashed (SLC cards, Display boards .etc) or could I buy a new FS-MB2 (motherboard with power supply) and everything should most likely work out?

What’s your opinion on this?

Whenever I have an issue like this, I first like to gather up everything I know before I start brainstorming. Now correct me on anything I get wrong here.

There are 2 cooked panels, both of which got fried within a couple of days. I am assuming they were using power from the same source, more or less. Both panels, when fried, used the same bridge rectifier. A fuse may have also been blown. I would start trying to figure stuff out using what info is given here.

Before you try changing the fuse and powering the panel up again, It would be good to know what caused the overload so it doesn’t occur again. You said you tested the fuse with an ohmmeter, if it is reading 0 or close to 0 ohms, the fuse is not blown. If it doesn’t give you a number (mine says OL), you have a blown fuse.

Since both panels shared the same bridge rectifier when this issue occurred, I would check that first. You are going to need a multimeter with a diode check function to do this.

Try to obtain a datasheet for the rectifier you are using, this will give you information needed for proper testing. This will also give some limits you should not exceed, it might be good to check them to make sure you didn’t go over them. A bridge rectifier is basically 4 rectifier diodes in one package that are connected in a certain way. Using the multimeter, red to anode side +, black to cathode side -, the meter should read the forward bias voltage of the diode. In reverse, it should read OL or something along those lines. A shorted diode would read 0.0 or something near that. A diode giving a reading other than OL when reversed is bad.

I would check the bridge first.

Do remember, this stuff is high voltage. I personally wouldn’t have done that without the proper connectors. Don’t re-apply power until you KNOW the problem has been resolved! Hope this helps.

Thanks TheBlueCFL,

Yes the 2 panels were using the same extension cord. The cord has bent prongs if that makes a difference? I tested the fuse from the FS-250 and the meter read “OL”. I just said nothing since there was no resistance at all (OL), sorry for the confusion. I’ve tested another fuse with the same meter and got a reading. So the FS-250 fuse is dead. That’s a simple fix. I’m worried that the whole MB2 board is fried! Is there a way I can check before spending $250 for a new one? Yes, I’ve used the same rectifier from the 4010.

Let me give you a backstory of the 4010.

I’ve received the panel Brand new last August and it’s always been a little funny. It would randomly go into IDNet Card loss, External N2 trouble, and NAC Power Supply missing, but would fix itself in a few seconds? The panel was working just fine, I put into into alarm and everything seemed fine until after I reset it. After I reset it, I heard a “pop” and those troubles mentioned above stayed permanently and loss communication with all my IDNet devices. There was a burning smell right below the SLC Terminal block but couldn’t find any burn marks or blown components?

I will check the bridge rectifier and get back to you tomorrow.

Could it be I have 2 or 3 other panels powered at the same time, along with a radio, and 3 fluorescent lights, that caused a surge?

Now that I remember, a month ago, I was testing my 7004t-115 under the same circuit using I believe that same extension cord. It sounded for a few seconds then it stopped? The gfci outlet it was using popped and the terminal under the Black “Hot” wire was charred. However the device still works.

If I replace the fuse and the rectifier would that most likely fix the issue? Or could I have blown the whole MB2 board? What’s more likely?


Another good thing that I have is something called a Kill A Watt, it is a device that plugs into your wall and has an outlet for a device to go into. It can measure things like power usage, line voltage and line frequency just to name a few. You can find one for 20 bucks on Amazon, get 5 for a couple dollars extra. If you are at all worried with the quality of power in your house, use one of these. I will be able to give more advice when I know the condition of the bridge rectifier.

I looked at the bridge rectifier in my 4010. It is a GBPC3501 which is a 100 volt 35 amp bridge. The quick specs are below.

Link to complete datasheet.

I’ve just tested the bridge rectifier that came with the 4010.

Using the diode test function on my meter, red lead to positive, black lead to negative, It starts with reading a number between 2.50 and 22.15 and then gives a - - - - - - - symbol? I’m assuming nothing? Black lead on positive and red lead on negative, I get a solid reading of about 0.22 . Using the ohm test function, I get OL no matter what side I use.

What do you make of this and what do you think is the fate of my FS-250 panel? Fuse or whole mother board?

The bridge rectifier has 4 diodes in it. Each should be checked both forward and reverse on the diode check scale. There should be some conduction reading forward biased and and no conduction in reverse. What the reading on the meter is will be unique to the brand and model of the meter. They are all different according to the meter internal circuits.

Your digital meter has a low power ohms scale. It is designed to be able to check resistors in circuit. It does that by being a low enough voltage that a semiconductor junction (diode or transistor) cannot be biased into conduction. A silicon diode junction takes about 0.7 volts to conduct so the meter output is around 0.4 volts max. So a good diode will read as open in both directions using an electronic ohmmeter.

Diode looks good. I was on the wrong setting on my meter, which is why it didn’t make full sense to me.

All 4 were tested and the forward bias read a solid 0.512 V and reverse bias gave nothing “OL”. So that looks ok to me.

I’ve uploaded a paint image on what I think caused the problem? Thoughts?

The shorting of the wires in the drawing shorted across D1 or D3 in the bridge drawing in my previous post. That would throw AC into the DC circuits. Not good. The “huge woosh” could be from several things that could be damaged. Examples would be electrolytic filter capacitors or regulator chips. The “60hz buzz that sounded like it was vibrating the metal” probably was from the excessive current being drawn from the transformer resulting from other parts failing or the short across one of the bridge diodes. That would cause a very big magnetic field around the transformer. The transformer most likely is OK. They are hefty simple parts that can take brief overloads in stride. The power supply section of the board could be toast. No telling about the rest of the board.

So it’s probably more than just the fuse? I can order another mb2 which I found cheap but there is a main display and DLC card attached to the fried motherboard. Would those be ok or fried as well, because I would have to transfer them? I found the pin connector for J4 so hopefully this doesn’t happen again.

When you start throwing 120V around circuits that are only rated for a max of 3.3-12 volts ver bad things happen very quickly. Like STR-SG said, there is no telling what broke. It could just be the PSU, or the entire thing could be dead. You won’t know until you start fixing things and see what works and what doesn’t.

If this surge caused a component on any of the boards to short, you may run into some more issues. If you replace one bad board, but another is shorted out somewhere, this may cause damage to the one you just put in. I can’t say for sure this will or won’t happen.

I ended buying a whole new FS-250 panel. This one has a cabinet and YES!! the bridge rectifier. Now hopefully the technicians password works on this one too. If not, I’ll have to buy a whole new MB2. Let’s hope that doesn’t happen.