Sartorius Portable PT 120-000V1, Руководство по обслуживанию

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Repairing the Balance/Scale
For PT...-000V1 and GT...-G00V1 balances/scales, we recommend exchanging the complete subassembly/
component groups if you locate defective components because the strain gauge system (106) is a complete unit in
itself and the main PCB (118) is equipped mainly with SMD components (Surface Mounted Devices). The SMD
components cannot be exchanged without the use of special tools. As a convenient service to you, SARTORIUS will
exchange any defective PCBs for an economical price.
The following component groups or individual parts may be exchanged with the use of standard tools and
equipment.
For repair:
strain gauge system (106)
main PCB (118)
parameter EEPROM IC109
LCD display AZ101
data interface YDO 01 TS (108) (option)
rechargeable battery pack (110-113) (option)
For adjusting or transferring components when exchanging the main PCB (118):
resistors R130 and R131 for adjusting the zero point offset value
resistor R104 or R105 for the linearity adjustment
If your service workshop is equipped with special tools for exhanging SMD components, repair of the PCBs at the
component level is possible. In this case, the „Table of Test Points“ (see page 30) and the „Overview of the Test
Points“ (see page 31) will help you locate any defective components more quickly.
After your balance/scale has been repaired, check the balance/scale functions and monitor the performance of the
balance/scale over a long period of time—especially with regard to drift, zero point offset value and calibration.
Important Note:
The number(s) written next to the components, e.g., PCB (118), refer to the exploded-view diagram on page 4.
Exchanging the Main PCB
- Disconnect the balance/scale from AC power.
- Open the balance/scale housing (see page 14).
- Remove the membrane-covered keypad (120.A) from plug-in position Bu.8,
the strain gauge system connecting cable (106.B) from position St.1, the
AC power connecting cable (109.A) from position Bu.4, and, if
applicable, the data interface cable (108.A) from position St.6 of the main
PCB (118).