Howdy, I have a customer and they had a power outage and DX80 at blew up, I replaced the whole system with a refurbished one from Starteltech. Everything was fine but the customer reported having trouble using DTMF digits to log into his mailbox remotely. I tried from my office and had the same trouble. So I replaced the voicemail and the problem continued.

Last time I was out I called themselves from their own line, for example I grabbed line 3 and called into line 1 and it worked perfectly every time. That would indicate to me I'm clear, but I wonder, the customer wants a refund on his phone system, the only thing I can do is swap out the KSU. Looks to me like a phone company issue but they come back no trouble found. Any thoughts or ideas?