Velleman Instruments PCS500 free download

File name PCS500_troubleshoot.pdf

PCS500 Troubleshooting If there are any fails or problems when you run the PCS500_TST.EXE at the first time on a new oscilloscope unit please make the following checks: Test 1 Problem No power Check The voltage at pin 6 of optocoupler IC30 should go down at the startup for a moment. See images 1 and 2. Check IC4, IC21, IC30 and the associated components. 2, 3 No trace on the screen Check all the supply voltages of the digital and analog section. Check the voltages of the input amplifier section. See image A. Check the waveforms at the optocouplers. See images 2 ... 8. When measuring the waveforms use "Single" mode and keep triggering ON. 4 5 6 7 8 9 10 11 12 13 14 15 16 Calibration error Can't be adjusted Can't be adjusted Can't be adjusted Can't be adjusted Can't be adjusted Can't be adjusted Calibration error Can't be adjusted Can't be adjusted Test failed Test failed Power can't be switched off Open CALIBRATION.LOG file and check the failed test. Below there are more detailed comments (Table1). Check the input section components (C14, C15, C80) Check the input section components (C14, C15, C80) Check the input section components (C20, C21, C81) Check the input section components (C20, C21, C81) Check the resistors of the input attenuator and the amplifier section. Check the resistors of the input attenuator and the amplifier section. Open CALIBRATION.LOG file and check the failed test. Below there are more detailed comments (Table1). Check the resistors of the input attenuator and the amplifier section. Check the voltages at IC24 (See image B). Check transistor T5 and associated components. Check the divider circuits IC9, IC10, IC11 and associated components. Check the trigger section components. The voltage at pin 6 of optocoupler IC30 should look like the waveform of image 2. Check IC4, IC21, IC30 and the associated components. Calibration results Test CH1 offset at 15V/div CH2 offset at 15V/div CH1 correction at 5V/div CH2 correction at 5V/div CH1 correction at 15mV/div CH2 correction at 15mV/div CH1 correction at 5mV/div CH2 correction at 5mV/div CH1 correction at 20us/div CH2 correction at 20us/div CH1 correction at 10us/div CH2 correction at 10us/div CH1 correction at 5us/div CH2 correction at 5us/div CH1 Trigger low CH1 Trigger middle CH1 Trigger high CH2 Trigger low CH2 Trigger middle CH2 Trigger high EXT Trigger middle Typical result 119 125 2 3 2 3 6 8 1 1 -1 -2 -5 -7 98 124 150 102 126 152 84 Table 1. OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK OK Acceptance range 100...156 100...156 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 -50...50 50...200 (CH1 Trigger low)+15...200 (CH1 Trigger middle)+15...200 50...200 (CH2 Trigger low)+15...200 (CH2 Trigger middle)+15...200 50...200 Voltages of the analog input section and the trigger section. All the voltage values below are allusive approximations only. A B C 0.0V 1.6V D 0.0V -3.4V Y-position Up Middle Do