01 The fault phenomenon

Switch on the ac power, turn on, FM20/FM30 fetal monitor has no response.

Maintenance analysis:

This kind of fault is generally easy to repair, first check whether the external power supply of the equipment is normal.If the external power supply is normal, most of the faults are caused by damage to the internal power board.Repair the power panel.

Repair method of power plate: disassemble.Check whether the ac insurance 2 T2A insurance are fused, and measure whether the +300V voltage is normal after exclusion.Measure the supply voltage of UC3842. If not, replace UC3842 directly, and the fault can be solved.

02 Malfunction: the boot screen displays a flower screen

Screen flower screen is generally divided into screen itself and screen data connection wiring fault 2 kinds, generally as long as the screen data wiring reinstallation and fastening.The FM20/FM30 fetal monitor screen can be moved up and down. After several years of use, it is easy to cause the aging of the data line or the looseness of the joint, leading to the display of the flower screen.

03 Malfunction: black screen at startup

Failure phenomenon: after the boot heard a drip, green indicator light, black screen.

Maintenance analysis: after starting up the host self-inspection after passing the sound will drip that the system runs normally.The black screen fault can be divided into two kinds of situations: completely black screen and indistinct sub-display.Maintenance needs to open the circuit inside the display.Measure the LCD backlight high voltage plate to see if it has a dc voltage of 23V.If the voltage is normal, only need to replace the LCD backlight high voltage lamp tube, the general fault can be eliminated.If there is no 23V voltage, it can be sure that the backlight high voltage output fault, directly replace the high-voltage plate can be repaired.

04 Failure phenomenon: main control board failure

05 Malfunction: the printer does not run

Printer work paper, can not hear the sound of the printer motor rotation, generally motor stuck or motor itself fault.First remove the motor mechanical fault, and then check whether the motor power supply is normal.There is a flaw in the design of this machine, that is, the motor is installed by the clamping spring or the card owner. Most printers cannot work because the motor's clamping spring is loose or falling off. If these problems are solved, the motor still cannot rotate, so the driver chip of A3967SLBT stepper motor is directly replaced.