B&K 1794 instruction manual Fault Finding Procedure, Fuse Blows

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FAULT FINDING PROCEDURE

( A ) FUSE BLOWS

	FUSE BLOWS
	Is Line Voltage OK ?	N
	Y
	Is Fuse Rating OK ?	N
	Is Fuse Rating OK ?
	Y
	Is Mains Transformer Tapping OK ?	N
	Y
	Are Power Diodes Connected	Y
	on Heat Sink Short ?	Y
	on Heat Sink Short ?
	N
	Is Remote Sense Switch Pressed	Y
	in Normal Condition ?
	N

Is Device Drop setting proper on Load ?

N

Turn ON the Unit at Rated input Voltage. Load the Unit at max rated Voltage and Current. Adjust the Voltage between Output Positive and Capacitor Positive between

4.5V to 5V by using Please VR1 on PREG PCB

Adjust Proper Line Voltage.

Insert proper rating Fuse.

Adjsut the Tap according to required voltage.

Replace the Damaged Diodes.

Release the Remote Switch in Normal Load Condition.

1.Check Line Voltage for 230V AC or 115V AC, whichever applicable.

2.Check whether Fuse Present is 20A for 115V AC I/P and 10A for 230VAC I/P.

3.Check the Transformer Tapping, whether it is configured accordingly to I/P Line Voltage.

4.The Power Diodes connected in Bridge configuration on Heat sink might be short.

5.If Remote Sense Switch is pressed on Load, in Normal Operation, there is chance unit may take High Current and Fuse might Blow.

6.If Device Drop measured across O/P Positive and Capacitor Positive is not between 4.5V to 5V at rated I/P Voltage and rated O/P Voltage and Load condition, there is a chance of Fuse getting blow in Load Condition.

Note : 4.5V to 5V Device Drop at Full Load.

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Contents BK Precision Limited Two Year Warranty Table of Contents Remote Programming With External 5K Pot Output ON/OFF SwitchLimit Setting Section General Information DescriptionSection Specifications Section Installation Repackaging for Shipment Input TAP Selection for 230V OperationSection Operating Instructions Readjust the current limit in the remote sensing mode Reverse Voltage Loading Output CapacitanceReverse Current Loading USE the Proper Power Cord Operators Safety SummaryTerms in this Manual Terms AS Marked on Equipment USE Care When Servicing with Power on Servicing Safety SummaryFor Qualified Service Personnel only Do not Service AloneTrouble Shooting Techniques Section Service Instruction GeneralServicing shall be done only by Qualified personnel Repairs & Maintenance Page Parts Ordering & Replacing REF. PCB no PIN noPage Page Fuse Blows Fault Finding ProcedureFuse 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 ControlPoor Line Regulation No Current ControlCV, CC, LED not Glow Poor Load RegulationPoor Load Regulation Remote Sense not OK External Programming not OKExternal Programming Not OK 2P2W SW Push Button Section Part List & SchematicsL1791-FP-CNT-0603 PCB Assy 1KPF/100V, DiscPS-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 AsslyMain Chassis Assly Front Panel 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