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Problem with repairing modem

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ahz

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I plugged my internal modem in the electricity outlet .I noticed my mistake after a while but the modem didn`t work anymore . I checked the board and substituted one of the resistors that was burned . it seems that the board dosen`t have any other problem and when i install the modem it is recognised by windows , however when i try to connect it always gives a " no dial tone " error .
if anyone has any idea how to fix the problem please reply.
 

The chances of fixing the modem are not good.

There is probably a line coupling transformer between the modem chip(s) and the telephone line. You may have blown the windings on that transformer.

If the transformer is OK, it is possible you blew the line drivers/receivers that are connected between the transformer and the modem chip(s). These I/O drivers/receivers may be integrated into the modem chip(s).

The PC side of the modem chip(s) could indicate proper operation, but the line side could still be toast. The same symtoms happen frequently after a lightning strike on a telephone line.
 

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