How to solve the problem with PBX LG IP LDK-100?

Question

Telephony

There is automatic telephone exchange LG IP LDK-100. There is a system phone LDK-30DS.
Today, the possibility of outgoing calls through 9 was gone. (silence on the phone). Also, incoming calls on the secretary's phone (system LDK-30DS) do not go through. The light is on to indicate that the line is busy, but the call is not coming through.
If you make an outgoing external call through a specific line 8801, 8802, then the call goes through.
Those. it works on a specific line, but not on the first free one.
Also the informant does not work. There was a thunderstorm yesterday.
Prompt in what direction to dig?

Answer 1

Flow board or port E1 (if it comes in digital) - diagnose with built-in tools (I won’t tell you which ones, I’m only familiar with Panas), or check analog lines and fenders (lightning protection) if it was.