Repair and review of HP/Agilent/Keysight 4263B

HP / Agilent 4263A and 4263B series LCR meter.

LCR meters and bridges are commonly used in power conversion and AC circuit applications. This bench meter able to measure lot of parameters in frequency range from 100 Hz to 100kHz, with base accuracy 0.1% at 1kHz frequency. It’s compact size allows both workbench and portable use on site. HP/Agilent 4263A is older model (Detail on vendor site) without voltage/current monitor and less informative segment LCD screen. It was replaced by 4263B with much better 40×2 character backlit LCD. This article covers only 4263B, but A-version likely to have same analog front end and measurement board.

Front panel interface and controls

It’s worth to check technical brief prior to controls evaluation.

Back I/O interfaces

User menu settings

Probe setup

All BNC shields should be connected on probe side, as it’s used as return path for signal generator and measurement circuits.

Internal construction


Firmware / ROMs / Files

Firmware with 001,002 working for 4263B

WinHEX template file for 4263B EEPROM EEPROM.tpl

WinHEX template file for 4263A EEPROM EEPROM.tpl

Firmware dumps from free_electron for 4263B

Different EEPROM screens with dumps:

Options and hacks

Hacking options on these obsolete LCRs described pretty well in here

Fully enabled 4263B with firmware version 1.06 power on message:

Performance check

HP 4263B with non-modified LCR eBay probe:
(Keithley 2002, 4W resistor with AVG filter, 10 NPLC, Nulled Rel, Math * 1000, so reading is in milliohm)

Cement 5W 0.1 ohm wirewound 5% (5W0.1RJ)

Vishay VCS101 0.02 ohm 1% 1W


Schematics for module Mx-Mx

LCD replacement to negative FSTN

Author: Ilya Tsemenko
Created: Sept. 10, 2014, 4:02 p.m.
Modified: Feb. 29, 2024, 11:10 p.m.