Thermo Scientific SAM12, Manual

Page: 165 / 176

Issue: 1.0 Maintenance and Trouble Shooting
Thermo Fisher Scientific SAM12 User Manual 11-17
back-light fails, see Display Backlight Failure (page 11-17) . If
the display fails to show any message, or is totally “blacked
out” proceed as follows:
1. Check the multi-cable connections from the display to
PL6 & PL7 on the Controller board.
2. If check 1 above has not revealed the problem, a fault
in the LCD module or Controller board is indicated.
3. Temporarily connect a spare LCD module to the
Controller board PL6 & PL7 (the back-light is
required).
If the message becomes visible, the fault is in the LCD display
module. This is not user serviceable and should be replaced
(with the back-light) as described in
LCD Display, Touch
Screen, Touch Controller & Backlight Inverter - Removal and
Replacement (page 11-8)
If no message appears, the fault is in the Controller board,
which should be replaced as described in
Controller Board type
5670A - Removal and Replacement (page 11-6) .
A power-on self Test switches on the back-light and produces a
series of “Self Test Messages” as each lamp is tested. If the
back-light fails to light, proceed as follows:
1. Check the cabling from the back-light inverter
enclosure to PL7 on the Controller board.
2. Check that 5 volts appears across the pins of PL7 when
the back-light should be on. If 5 volts is apparent then a
fault in the LCD or back-light inverter is indicated.
These items are not user serviceable and should be
replaced as described I,
LCD Display, Touch Screen,
Touch Controller & Backlight Inverter - Removal and
Replacement (page 11-8)
is absent across the pins of
PL7, a fault on the Controller board is indicated and it
should be replaced as described in
Controller Board
type 5670A - Removal and Replacement (page 11-6) .
If the SAM12 starts and runs but will not accept a valid
password, a fault is indicated either in the LCD Touch-pad or
the Controller board. Proceed to
LCD Keypad Inoperative or
Not Aligned (page 11-17) .
If the SAM12 Starts and runs but will not respond to password
entry or returns incorrect characters on the LCD display, a fault
is likely in the Controller board or possibly the keypad.
Proceed as follows:
Display Backlight Failure
Will Not Accept Valid
Passwords
LCD Keypad Inoperative or
Not Aligned