Racal Instruments 3152 User Manual

Also see for 3152: User manual

Contents

Racal Instruments 3152 User Manual Manual pdf 103 page image

Maintenance and Performance Checks 5-17The troubleshooting procedure should also be initiated wheneverthe synthesizer fails to perform either completely or partially. It isalso required to troubleshoot the Model 3152 whenever theinstrument fails to fully comply with its published specifications.The information given in the following does not intend to replacefull scale troubleshooting, but merely to direct the ServiceTechnician to the area were the source of the trouble is located.Main BoardCircuit CheckoutThe Model 3152 is made of two boards. The large board (PartNumber 7100-2370) is the main board. There is a smaller boardmounted on the main board with three connectors (Part Number7100-2360). This smaller board is called the “engine board”. Thefollowing checks are made on the main board. To gain access tocomponents below the engine board, it may be necessary toremove this board entirely. To do so, remove the three screws thattie the engine board to the main board, grasp the engine boardfrom both sides and pull away from the main board.Power SupplyCheckoutIt is suggested that the first step in troubleshooting the Model 3152would be to check the power supply rails. If the various supplyvoltages within the instrument are not within the required limits,troubleshooting the remaining circuits can be very difficult.The supply voltages are supplied to the Model 3152 through thebackplane. In case of a "dead short" between one of the suppliesto the common ground, disconnect the entire supply section fromthe remaining circuitry, and then determine whether the problemis in the power supply or in the remaining circuits.A few preliminary checks could help here. First remove the Model3152 from the VXIbus chassis. Turn on the VXIbus chassis andverify that the supply voltages are available directly on thebackplane sockets. Check the following supplies: +24V, -24V,+12V, -12V, +5V, and -5.2V. Check the ripple on these lines usingan oscilloscope.Plug an extension card into one of the slots and plug the Model3152 into the extension card. Turn the chassis power on andrepeat the supply voltage tests as above. If one of the voltages ismissing or not within the specified range, it is possible that one ofthe supply lines is shorted inside the Model 3152. Remove the filterchokes L12 and L13 if there are problems on the +24V or -24Vlines; remove L8 or L9 if there are problems on the +5V or -5.2Vlines, or remove L10 or L11 if there are problems on the +12V or-12V lines.CPU and VXI ASICCheckoutThe most important section to be verified after power supplycheckout is the CPU and the VXI ASIC section with its variousclocks, address, data lines, and chip select serial datacommunication components. Problems with the digital part couldcause erratic operation or erroneous response to word serialcommands.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com