B&K 1794 instruction manual No Current Control, Poor Line Regulation, Preg PCB

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( H ) NO CURRENT CONTROL.

NO CURRENT CONTROL

Is Current Pot Open ?

Y

Replace it.

N

Are Wires related to Current Pot OK ?

Y

Ensure proper Connectivity.

1.Check the Current Potentiometer. It might be Open.

2.Check all Wires related to Current Potentiometer.

( I ) POOR LINE REGULATION.

POOR LINE REGULATION
Improper Device Drop Setting.	Y	Keep the Input Supply at rated I/P.
		Keep the O/P Supply at rated Vtg.
N		and rated	Load. Measure Vtg.
		across O/P	+Ve and Capacitor
Leaky Summing Capacitor C4.		+Ve Adjust that Vtg. between 4.5V
Y		to 5V with Preset VR1 ( 5K ) on
Y		PREG PCB.

Replace It.

1.Check whether Device Drop is between 4.5V to 5V. It might not be proper.

2.Leaky Summing Capacitor C4 on PREG PCB.

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Contents BK Precision Limited Two Year Warranty Table of Contents Section General Information Description Output ON/OFF SwitchLimit Setting Remote Programming With External 5K PotSection Specifications Section Installation Input TAP Selection for 230V Operation Repackaging for ShipmentSection Operating Instructions Readjust the current limit in the remote sensing mode Reverse Current Loading Output CapacitanceReverse Voltage Loading Terms in this Manual Terms AS Marked on Equipment Operators Safety SummaryUSE the Proper Power Cord Do not Service Alone Servicing Safety SummaryFor Qualified Service Personnel only USE Care When Servicing with Power onServicing shall be done only by Qualified personnel Section Service Instruction GeneralTrouble Shooting Techniques Repairs & Maintenance Page REF. PCB no PIN no Parts Ordering & ReplacingPage Page Fuse Blows Fault Finding ProcedureFuse Blows Unregulated O/P Voltage Unregulated O/P VoltageNo Output Voltage No O/P VoltageNo DPM Indication No DPM IndicationDPM not Read Unit not Take Current Unit not Take CurrentUnit Directly Goes to CC Unit Directly Goes To CCNo Current Control No Current ControlPoor Line Regulation Poor Line RegulationPoor Load Regulation Poor Load RegulationCV, CC, LED not Glow External Programming Not OK External Programming not OKRemote Sense not OK 1KPF/100V, Disc Section Part List & SchematicsL1791-FP-CNT-0603 PCB Assy 2P2W SW Push ButtonSW1 Grey Colour CAP for Push Switch SW2 SW3 PS-PREG-1791-0503 PCB AsslyDPM/01 REV 01 X PS-AUX-DC-L1791-0503 PCB Assly PS-PWR-L1791-0703A PCB AsslyBack Trough Assly Front Panel AsslyMain Chassis 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 Service Information Precision CorpPrecision Corp