Steps and Methods


1． Observation: To estimate the problems by observation.
2． Enquiry: To enquire the phenomena in the use of the instrument and in the event of its failure.
3． Smelling and hearing: To estimate whether the parts of the instrument burnt out by smelling and whether it has some abnormal sound by hearing.
4． Dealing with the connector: To estimate whether the instrument can’t be connected successfully or has the problem of oxidation by shaking the instrument or fixing the connector again.
5． Substitution method: To use the new fittings instead of the old ones.(notation: to make sure it is not short circuit)
6． To estimate the problems on the grounds of its using life:
Most occasional problems maybe caused in the new instrument. Shaking in the transportation can make the connector can’t be connected successfully or the adjustable fittings to work a change even several fittings sheared off. Adjusting and fixing the loosened connector carefully can solve it; Most old instrument may have some degenerative fittings like the decline of electrolyse, capacitance. (it is Especial for older instrument), creepage, breakdown and the change of the resistance. Different kinds of transformers and loops are affected with damp, go moldy and break down and the transistor and the integrated circuit are damaged.

The usual interference

(1) The usual problems of B mode ultrasonic diagnostic instrument.

1． If some dynamic skew line or some rolled signal in the signal region and some fluid bright and dark line signal change, it will be the interference.
Solving method:
(1) To add the regulated power supply.
(2) To check the ground cable.
(3) To eliminate the interference: such as electrical machine, welding machine, large-scale transformer, high-tension wires, CT machine, X bean machine, coiled electric wire, large-scale machine, etc.
(4) Short circuit of the shielding line and signal line or failed connection of the shielding line.
(5) The interference of other additive equipment: Poor quality of the manostat can cause the interference of the instrument. You can estimate it by cutting off the additive equipment.

(2) The usual problems of the power supply

1． It will burn the fuse as soon as electrifying
Solving method:
(1) To check whether the commute diode is being short circuit.
(2) To check whether the switch dynatron is being short circuit.
(3) To check whether the filtering capacitance is being short circuit.
2. No output of the power supply current carrying
Solving method:
(4) To check the starting resistance
(5) To check the switch dynatron
(6) To check the voltage regulation circuit
3. The power supply voltage is unstable
Solving method:
(7) To check the return circuit of the main voltage regulation
(8) To check the return circuit of different groups of voltage regulation.
4. At first there is the output of the power supply which is switched on , then it will fall to 0 V.
Solving method:
(1) Mainly caused by the protection circuit: A: The power supply problem
B: Load short circuit leads to the electric current too large.
5. Power supply interference
Solving method:
（1） Mainly caused by the bad filtering electrical circuit.(especially the electrolysis and the capacitance)

（3）The usual monitor problems

1． No display, the display light isn’t work
Solving method:
(1) To check 12 V service voltage
2． No display, the indicator light is work
Solving method:
(1) To check the brightness, vice-brightness and the contrast potentiometer
(2) To check the line scan circuit and the high voltage formed circuit
(3) To check the display circuit
3． The image rolls up and down
Solving method:
(1) To check the field frequency potentiometer
(2) To check RC timing circuit.
4． Compressing (up and down) of the image
Solving method:
(1) To check the potentiometer of the field height.
5． Bad linearity of the image
Solving method:
(1) To check the potentiometer of the vertical linearity
(2) To check the feed back circuit
6． Dithering (left to right or right to left) of the image
Solving method:
(1) To check the potentiometer which acts on the line scan
7． Dithering (up and down) of the image
Solving method:
(1) (1) To check the potentiometer of the field height
8． The image is contorted
Solving method:
(1) To check whether the voltage or the power is a little lower.
(2) To check whether the feed circuit of the field circuit waves excessively.
9． The character or the image is blur
Solving method:
(1) To adjust the potentiometer of the brightness and contrast.
(2) To adjust the focus potentiometer
(3) To replace the aging kinescope with a new one.
10. Horizontal bright lines run through the monitor
Solving method:
(1) To check whether the anode voltage is too high and the cathode voltage is too low and whether there is some slight pulse signal.
(2) To adjust the potentiometer of the vice-brightness and the brightness.
11. There is some dynamic wave interference in the whole screen
Solving method
(1) To check whether the shield of the signal line is in good condition.
(2) To check whether the wave of the service voltage of direct current is excessive.
(3) To check whether the potentiometer of the vice-brightness and the brightness is in bad condition.
12. The monitor blacks out from time to time.
Solving method:
(1) To check whether the voltage of the power supply is steady.
(2) To check whether potentiometer of the vice-brightness and the brightness is oxidized.
13. Striking fire of the high voltage in the monitor.
Solving method:
(1) To keep ventilated, dry, being repelled by light and getting rid of humidity. In addition, to pressurize by high voltage silicon paper.
(2) To clean around the lid of the high voltage and keep clean.
(3) To change the lid of the high voltage.
(4) To change the transformer of the line scans.

(4) Mouse problems

1. The cursor only move to one side when moving the tracking ball:
Solving method:
(1) To clean the tracking ball or to adjust the roller.
2. No cursor signal on the screen:
Solving method:
(1) To connect the mouse again.

(5) Panel problems

1. Parts of the key-press is not work
Solving method:
(1) To check whether the panel and the data wire of the main board are connected well or the datawire is in good condition.
(2) To check whether the spring strip is good and to change it.
(3) To clean the oxide layer on the spring strip and the main board.
(4) The socket of the panel and the horn of the main board are not welded well.

（6）Other problems and solving method

1. Narrow dark line in the region of the image
Solving method:
(1) To check whether the probe is connected with the main machine well. If not, connect it again.
(2) Probe problem: To use a slippery metal bar slip on the surface of the probe , be disconnected, then press the“left to right” key and use a slippery metal bar slip on the surface of the probe again, if the disconnected part move, it will be the probe problem.
(3) To check whether the receiving and sending board was burned out.
2. Some bright lines about 1cm in width like the steps and some dark erect shadow in the region of the image
Solving method:
(1) To check whether there are some probe interference.
(2) Bad connection between probe and main machine.
(3) To check whether the probe was burned out.
3. The mosaic-like image appears in the whole screen.
Solving method:
(1) To check whether the microcomputer CPU integrated circuit was damaged.
(2) To check whether the microcomputer storage was damaged.
(3) To check whether the dropout line is not connected well or the dropout socket is not welded well, or there is the short circuit in the dropout line.
(4) To check whether the integrated circuit of the microcomputer is loosened.
4. Automatic freeze
Solving method:
(1) To check whether the freeze key is in good condition.
(2) To check whether the foot switch is in good condition.
（3）To check whether the microcomputer board in good condition.
5. The fan of the instrument runs, the probe sounds, no signal of the probe.
Solving method:
1, to check whether the probe is connected to the socket well, can connect it again.
2, to check whether the datawire and the main board is loosened.
3, to check whether are the probe in good condition.
4, to check whether the receiving and the sending board has some problems.
5, to check whether the power supply is in good condition, if there isn’t the 130V or only scores of voltages, it may be the startup resistance270K and 1K of the power supply is out of order.
6. No character display on the screen, but the adjustment of the bright and darkness is normal.
7. The operation is normal, but the vertical dark belts appear on the screen and no effect to adjust the brightness and the gain.
Solving method:
(1) To check whether the device of the receiving and sending board is out of work, and or it will lead the receiving and sending circuit works abnormally
(2) To check whether the probe is damaged or the connector isn’t connected well.
8. There is the grating but no image, no gray scale, and no graduation.
Solving method:
(1) To check whether the clock module is out of work.
(2) To check whether the monitor has any problems.
(3) To check whether the microcomputer board is belong to my company.
9. No grating, no image.
Solving method:
(1) To check whether 12V power supply is in good condition.
(2) To check whether the monitor is in good condition.
10. There is the grating, graduation, gray scale, but no ultrasonic image.
Solving method:
(1) To check whether –12V ,±130V power supply have problems.
(2) To check whether the receiving and sending circuit is in good condition.
(3) To check whether the storage circuit is in good condition.
(4) To check whether the probe is in good condition.
11. The vertical bright lines drift in the region of the ultrasonic image.
Solving method:
(1) To check whether the receiving and sending delay-time is stable and the delay line is normal.
(2) To check whether the receiving and sending circuit is in good condition.
(3) To check whether the probe is in good condition.

12. No effect of the freeze
Solving method:
(1) To check whether the freeze key is damaged.
(2) To check whether the microcomputer board is in good condition.
13. The time stops after shutting off
Solving method:
(1) To check whether the clock module is damaged.
14. The power supply shouts when switching on.
Solving method:
(1) To check whether –130V is being short circuit.
(2) To check whether 6250 dynatron in the channel is being shot circuit.
15. Double shadow
Solving method:
(1) To check whether the high voltage power supply is damaged.