5. TROUBLE SHOOTING
Service information Phyaction 190 / 190i - Page 14
6) The Liquid Crystal Display is initialized and tested.
ERROR 21
is generated on a time out. Since this
error message most probably cannot be displayed, 1 longer beep and three short beeps are generated.
7)
The I²C bus is initialized and tested.
ERROR 11
is generated on a time out.
Value
will show the address
of the device that has caused a time out.
8) The second part of the program EPROM is checked (Checksum). If an invalid checksum is found
ERROR 05
is generated and 6 beeps will sound.
9)
The keyboard is checked. If a key is pressed during self test
ERROR 41
is generated. The key that is
pressed is shown in
Value
.
10) The I²C E²PROM (the non-volatile memory) is checked. If it contains an incorrect checksum
ERROR 31
is generated with the (new) checksum as
Value
. If the E²PROM has an invalid signature,
ERROR 32
is
generated.
11) A reference voltage of 2.5V is measured. If the measured value is above
2.63V
(
086h
) or below
2.39V
(
079h
)
ERROR 56
is generated. The measured 8-bit AD value of Vref is shown as
Value
. With this
reference voltage both the reset IC and the ADC are checked.
12) The Intensity potentiometer is checked. The reference voltage on the potentiometer must be between
3.75V
(
0BFh
) and
4.40V
(
0E0h
), otherwise
ERROR 54
is generated. Further, the voltage of the
potentiometer must correlate with the zero-switch of the potentiometer. If the switch indicates that the
potentiometer is in its zero position, the measured voltage must not exceed
0.19V
(
00Ah
), or else
ERROR 55
is generated.
Test of the ultrasound unit
Checking the treatment head types
During self test the microcontroller checks the voltages from the treatment head resistors. If an unknown head
is found, i.e. if a voltage is not between
0.88V
(
02Ch
) and
1.48V
(
04Bh
), between
2.20V
(
070h
) and
2.80V
(
08Eh
) or above
4.90V
(
0F9h
),
ERROR 58
is generated.
Value 10
indicates an invalid voltage on the left
output, while
Value 01
indicates this for the right output. During normal operation an unknown head type does
not generate a critical failure. During start-up though, it could indicate a hardware error in the head detection
hardware.
Checking the ultrasound voltage
1) After power on of the unit the PWM is in its minimum position (
0
/
255
). Any voltage still present in the
ultrasound unit (e.g. caused by a rapid off and on switching) is discharged by switching the ultrasound unit
on for a short moment. Next Vsense is measured and should be below
3.0V
. If Vsense is above this value,
ERROR 51
is generated.
2) The PWM is set to a value close to maximum (
235
/
255
). The ultrasound voltage should reach at least
23.5V
within appr. 40 msec, otherwise
ERROR 52
is generated.
The two values that are just measured (at PWM 0 and PWM 235) are used to determine the behaviour of the
SMPS power supply.
3) The duty-cycle is set to zero and Isns is measured. The voltage representing Isns should be below
0.05V
,
otherwise
ERROR 59
will be generated.
4) The PWM is set to its minimum value (
0
/
255
) and the ultrasound unit is activated. Now the ultrasound voltage
should reach a value of less than
17.0V
within appr. 1 second. Otherwise
ERROR 53
will be generated.
5) During self test and also during normal use the PLL is checked on not going out of lock. If the PLL does go
out of lock,
ERROR 60
is generated.
Other tests during normal use
The following tests are performed on a regular basis during normal use:
1) The internal temperature is checked. If it goes above appr. 45
°
C, the fan is switched on. Should the inner
temperature rise above appr. 65
°
C, a critical error:
ERROR 70
is generated.
2) The reference voltage over the intensity potentiometer is tested constantly. If this voltage is outside its limits
(from
3.75V
(
0BFh
) to
4.40V
(
0E0h
) ), a critical error is generated (
ERROR 54
)
3) The PLL is tested during body contact measurement. If the PLL goes out of lock
ERROR 60
is generated.
This error can be caused either by the PLL or by a malfunction in timer 2.
4) The ultrasound voltage is constantly checked. If this voltage is higher than
28.5V
,
ERROR 57
is generated.
5) Every time an I²C device is accessed, the I²C protocol is checked on a time out. If a device does not respond
within a certain time limit,
ERROR 11
is generated, with
Value
the address of the not responding device.
6) Every time the LCD display is accessed it has to respond within a certain time. Otherwise
ERROR 21
is
