Our church had a lightning strike on a tree near the building. The snowstorm in Texas earlier this year caused major water damage so our insurance isn’t covering the lightning issue.
The MS5210UD suffered several failures including ground faults and zone faults. I’m a retired EE so I volunteered to fix it. All the zone faults and ground faults have been fixed and I actually had all the correct parts in my spare stash…comes in handy having tons of experience repairing equipment as a “hobby” for friends and family.
Surprisingly, none of the bad components burned; they either shorted or opened so there is no visible damage.
The only remaining problem is the secondary POTS port. We switched over to an AES Cell unit last year so both ports are wired to that and have been working fine until now. The panel reports “No 2” as the only fault now. Troubleshooting mode seems to work OK for both ports and I get the same “off hook” voltage at the phone transformer for both ports. None of the MOVs are shorted and the thermistors aren’t open and the relays work so I am assuming the problem is in the detection circuit for the secondary. The cell system works if I trigger the panel with a pull switch so the primary is obviously working.
There aren’t any burned traces that I can see. Any clue to what makes up the detection circuitry? Or hopefully a schematic?
Any help is much appreciated.
Thanks,
Michael