Sharp FO-DC550 worked previous to customer reconnect

[axyun]

I delivered a used FO-DC550 to customer. It was working on a dedicated line for first few days. Then customer had a line problem which Verizon acknowledged and customer was unable to use this or one of 2 other machines.
Customer reconnected to another line in another location in office but connected it to a 2 way splitter. The customer was unable to send and receive although receiving was more reliable. I stopped by and turned speaker on and could hear static or noise at times. When I connected a Fo-Dc535 I did not hear the static and customer was able to use that machine except it has laser problem and gets regular laser error codes but can use the machine intermittently. I don't know if there is a problem with the Fo-DC550 or if it is not able to function proper on splitter although the DC-535 is able to. There is a 3rd Sharp fax which has been down for a while that has not been able to send but it too can receive faxes on the splitter. I am not sure what model it is but might be FO-4700.
I have an AR-FX9 fax kit which has same modem board and thought I might try swapping it on Monday. Is this a bad idea. Is it possible that the FO-DC550 modem board is at risk on a splitter that the other machines are protected from. Please advise.Frank/ActionPhotocopy

[axyun]

Re: Sharp FO-DC550 worked previous to customer reconnect

Went back today and swapped modem board. Still go t noise on line when I pressed speaker. Two way splitter is shared with a computer internet connection. So some kind of dsl interference, The thing is it does not happen with a Sharp FO-4500 or a Sharp Fo-Dc535. They have other problems from before which have nothing to do with line which is why customer bought Fo-DC550 from me.
When I took off splitter and just connected FO-DC550 to line the machine worked fine and no noise on line. So the Fo-DC550 is more sensitive to sharing the line. I am looking into a dsl filter to see if it will make a difference. Frank