Magix power supplies keep blowing 1

[mikedphones]

We have a client with a 2 carrier Magix. It has been installed for many years, never had a water issue. Climate control is fine.

The 1st (main) carrier power supply blew about a month ago and had soot marks at the top. We replaced it and 2 weeks later, phones blinked a few times and within hours, it was dead again. 3rd and 4th over the last 2 weeks, same thing.

Could a circuit pack blow power???

Slot 1 412
slot 2 412
slot 3 024
slot 4 024
slot 5 DS-1

slot 6 mail
slot 7 016 trr
slot 8 016 trr

No water, no recent construction, no UPS either, however it has blown during the day while we are there.

Where would I start? Carrier? Processor?

Thanks

Mike D

 

[CarGoSki]

You probably should have replaced the backplane. Perhaps you will find carbon on the carrier slot pins when you shut down to inspect the pins. Perhaps you will find some conductive dust in a carrier slot.

You should check input power outlet with a multimeter and check grounding voltage potential.

Use system monitor unless of course you are a Tard then it IS the fault of the pbx.

 

[dagwoodsystems]

The backplane IS the problem--for a fact. I could go into great detail about the edge connector and every conductor's responsibility, but that's unnecessary.

If you trouble yourself to look at the power supply's edge connector, you'll find burnt marks about 2" from the bottom across two to four copper traces.

This problem happens when a metal carrier is installed or tweaked into a rhombus. Doing so will cause conductors in the power supply to short across the backplane.

Typically, this does NOT cause a problem with the -48V source, but rather the -5V source. The switch will often power up in this condition, but 5V modules like T1/PRI cards and/or voicemail will NOT come alive.

DO NOT try to solve the problem by simply replacing the power supply...you'll just blow another one. Instead, grab one of those super deals that include a cabinet, power supply and processor and go from there.

Tim Alberstein

http://www.dagwoodsystems.com

 

[mikedphones]

Thanks to both of you for the suggestion.

Saturday we replaced the main carrier, which included a new power supply. Today, Sunday, it is down again. The customer told me the phones were up and down a couple of times, message lights blinking, and then the usual death of the system.

As I mentioned in the original post, it is a 2 carrier system and it is always the first carrier that goes. The system has been hanging on a solid, non vibrating wall. By this I mean, people slamming a door aren't an issue, etc.

I am lost. I have never seen a module take down a power supply. The pins between carriers are of interest to me, and maybe the bus coming back from the exp carrier, however, I would think that it would stay in its own carrier.

Any other thoughts guys? I am terrified to replace all those mods! I will check the error log too, but don't recall anything jumping out at me.

Thanks!

 

[mikedphones]

Additional followup. When I call up there, sometimes I get through, other times I do not, I get a busy. This most likely lines up with the phones blinking on and off and the T1 synching up and down each time.

Monday morning, I am doing the entire system in clamshells with 2 391C, 1 new processor, and reusing all other mods. Wish me luck!

Mike

 

[dagwoodsystems]

And yes, an individual card can cause others to blow. I used to think that wasn't the case, but I recently had to replace all but one card in a two-carrier switch at a site for that very reason.

A failed 800DID blade had been receded from the backplane after determining that it's failure was what kept the switch from booting up. The goal was to leave it out until I got out there with a replacement, but somebody got impatient and decided to slide the card back in anyway (WITH the switch powered up). Ooops.

So yes, I'd bring all that you can with you and expect the worst.

Tim Alberstein

http://www.dagwoodsystems.com

 

[Dexman]

Just curious, is the power supply grounded?

If it ain't broke, I haven't fixed it yet.

 

[mikedphones]

Hi all. Yes, the PS are grounded. Switched all over to plastic, and actually pulled what I originally called the T1 card which in this case was an INA card which wasn't really needed. While going to plastic, I used a regular 100D instead. Hopefully the plastic and the regular T1 will put this to bed! I will keep you in the loop.

 

[CarGoSki]

They may have a ground wire attached but have you tested for voltage potential with a miltimeter. BTW daisy chained ground wiring does not count and should be changed.

Use system monitor unless of course you are a Tard then it IS the fault of the pbx.

 

[mikedphones]

Thanks, I will check that with a meter and confirm no daisy chain.

 

[Dexman]

A former contributor to Tek-Tips discovered the "ground potential" issue when one of his customers blew 2 Partner ACS processors. He rectified the situation by connecting the ground screw on the processor to the ground on the AC outlet that was powering the system.

If it ain't broke, I haven't fixed it yet.

 

[CarGoSki]

Is he a "former" contributor because a pbx finally killed him?

Use system monitor unless of course you are a Tard then it IS the fault of the pbx.

 

[Dexman]

Is he a "former" contributor because a pbx finally killed him?

No comment.

If it ain't broke, I haven't fixed it yet.