B&K 1794 instruction manual No Output Voltage, No O/P Voltage

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( C ) NO OUTPUT VOLTAGE.

	NO O/P VOLTAGE
	Is IC LM324 OK ?	N
	Y
	Is Voltage Pot Short ?	Y
	Is Voltage Pot Short ?
	N
	Is Voltage Selection Preset Open ?	Y
	N
	Are Zener Diodes Z1 & Z2, Preset	N
	VR1 on Preg. PCB OK ?	N
	VR1 on Preg. PCB OK ?
	Y
	Are all the Auxillary Winding	N
	Reaching PCB ?	N
	Reaching PCB ?
	Y
	Is there proper contact of Load	Y
	Terminal with Terminal Nuts	Y
	Terminal with Terminal Nuts
	Inside Unit.

Replace It.

Replace It.

Replace It.

Replace It.

Ensure their proper Connectivity with PCB.

Ensure proper Connectivity of Load Terminals and

Terminal Nut inside.

1.Check IC LM324 on Front Panel PCB L1791-FP-CNT-0603. It might be Damaged.

2.Check the voltage Potentiometer. It might be Short.

3.Check Voltage Selection Preset R22 on Front Panel PCB. It might be Open.

4.Check Preset VR1 on Pre-regulator PCB (PS-PREG-1791-0503). It might be Open.

5.Check whether Auxillary Transformer Windings are reaching PCB.

6.Check whether there is proper contact between Load Terminals and Terminal Nuts inside the Unit.

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Contents BK Precision Limited Two Year Warranty Table of Contents Limit Setting Output ON/OFF SwitchSection General Information Description Remote Programming With External 5K PotSection Specifications Section Installation Repackaging for Shipment Input TAP Selection for 230V OperationSection Operating Instructions Readjust the current limit in the remote sensing mode Output Capacitance Reverse Voltage LoadingReverse Current Loading Operators Safety Summary USE the Proper Power CordTerms in this Manual Terms AS Marked on Equipment For Qualified Service Personnel only Servicing Safety SummaryDo not Service Alone USE Care When Servicing with Power onSection Service Instruction General Trouble Shooting TechniquesServicing shall be done only by Qualified personnel Repairs & Maintenance Page Parts Ordering & Replacing REF. PCB no PIN noPage Page Fault Finding Procedure Fuse BlowsFuse Blows Unregulated O/P Voltage Unregulated O/P VoltageNo O/P Voltage No Output VoltageNo DPM Indication No DPM IndicationDPM not Read Unit not Take Current Unit not Take CurrentUnit Directly Goes To CC Unit Directly Goes to CCPoor Line Regulation No Current ControlNo Current Control Poor Line RegulationPoor Load Regulation CV, CC, LED not GlowPoor Load Regulation External Programming not OK Remote Sense not OKExternal Programming Not OK L1791-FP-CNT-0603 PCB Assy Section Part List & Schematics1KPF/100V, Disc 2P2W SW Push ButtonPS-PREG-1791-0503 PCB Assly SW1 Grey Colour CAP for Push Switch SW2 SW3DPM/01 REV 01 X PS-PWR-L1791-0703A PCB Assly PS-AUX-DC-L1791-0503 PCB AsslyFront Panel Assly Main Chassis AsslyBack Trough Assly Front Panel Layout Back Panel Layout TOP View Bottom View of Model 1790 Front Panel Control PCB of 1790 Power Module PCB of 1790 PRE Regulator / AUX. P/S PCBs 1790 Precision Corp Service InformationPrecision Corp