User Manual DDS200 Digital Demodulation System 070-9952-00

Maintenance and TroubleshootingReplacing the BatteryWARNING. To prevent injury, avoid short circuiting or charging the battery. Shortcircuiting the battery can cause the battery to explode. Do not open dischargedbatteries; dispose of batteries as hazardous waste.The instrument has a lithium battery for storing the selected status and foroperation of the real-time clock. The battery has a lifetime of approximately fiveyears and should be replaced as required (for example, after a long storage periodat high temperature). Replace the discharged battery with one of the same type.WARNING. Disconnect the power cord from the rear-panel of the DDS200 beforeopening the instrument. Failure to do so could expose you to risk of injury oreven death.The battery is located on the processor board. With the unit open, that is, afterfolding down the rear panel, the processor board is located at the bottom right, asviewed from the rear panel. the processor board can be recognized by the flatcable connected to the rear panel.Disassembling and opening the processor board:Disconnect the flat cable.Release the locking bracket on the right of the processor assembly using aPhillips screwdriver.Pull the processor board to the rear.Open the upper shield cover of the processor board using a Phillipsscrewdriver.The battery is located on the left front near the large multi-way connector.To install the battery properly, solder its terminal lugs and fix it by means ofcable ties. Make sure to get the polarities right. Polarity is indicated with “+” and“–” on the battery and also on the processor board. The symbols on the batteryhave to match with those on the processor board.TroubleshootingOn power-up, all assemblies are coarsely checked for their presence and theiroperation (power-up screen mask). If a failure is detected, it will be signaled onpower-up. It is therefore necessary to observe the power-up sequence.4–2 DDS200 Digital Demodulation System User Manual