Analysis and Maintenance : According to the analysis of failure phenomena , the machine will automatically receive faxes , indicating communication and other equipment were not part of the circuit failure . It should first check the "start" button is normal, the examination was normal.

 

Then powered self-test , followed by pressing the "function" function key → number "7 " key → "tel / dial" button ( 4 ) → "*" key , the machine enters the device test mode . Then press the number "3 " key → "start" button to start itself automatically print out the data and functionality ram parameter table . Carefully inspect the function parameter list , the parameter values ​​have been found to be initialized to the initial setting state where the fax machine is automatically reset.

 

Analyzing the power supply circuit for the machine equipment failure, the power supply circuit includes a battery pack pow1 , the transistor q7, q8, reset switch sw2 other components. The circuit is mainly used to ram uninterrupted power supply to ensure that their data parameters and clock signals are not lost due to power .

 

According to the analysis , the first test with a multimeter pow1 battery pack voltage is normal , the examination was normal . Then test sw2 switch position is normal, contact is good , under normal circumstances, sw2 switch is in the "on" on the block . With a multimeter "r × 1" block lug along sw2 were tested printed circuit board off the case , the test found that , "on" the end result of a long period of lug wet conditions and mildew off . Replacement , re- setting function values ​​, troubleshooting.