Shaun Merrigan's Information Pages


Category: Test Equipment


HP 3562A ROM Repair

Posted by Shaun Merrigan in Electronics, Test Equipment. Comments Off on HP 3562A ROM Repair

26th December

Early in 2018, I purchased an HP 3562A Dynamic Signal Analyzer for an excellent price on Ebay. The display looked great and it was physically in good condition. However, the unit failed the power on self test as follows:

HP 3562A Error Message on boot

This error code indicates a ROM IC failure.

HP3562A Diagnostic LED’s indicate Hex code 4 4 (0100 0100)

This code indicates a failure of ROM Chip U105:

HP 3562A Rev B ROM board. The problem ROM chip is the fifth chip down in first column (U105)

HP 3562A ROM Board Rev B

This ROM board is an older version using 32kx8 chips in two groups (Low Byte & High Byte) of 18 chips each. I had access to a second 3562A, and swapping ROM boards confirmed that the ROM board was the problem. Now I needed to:

Locate a suitable set … Read More »


Tektronix CG5001/CG5011 Pulse Rise Time Measurement

Posted by Shaun Merrigan in Electronics, Oscilloscopes, Test Equipment. Comments Off on Tektronix CG5001/CG5011 Pulse Rise Time Measurement

25th September

Tektronix CG5001/CG5011 Pulse Rise Time Measurement

I wanted to measure the rise time of the normal and fast edge pulses in a new acquired Tektronix CG5011 calibration generator.  The equipment line is as follows:

Tektronix TM5006 mainframe

Tektronix CG5011 Calibration Generator

Tektronix CG5001 Calibration Generator

Tektronix/Tegam 015-0611-01 Pulse Head

HP 83480A Communications Analyzer

HP 83483A Electrical Sampling Module (20GHz)

Background:  The original 015-0311-00/01 pulse head was used in combination with the CG551AP and CG5001 calibration generators. The 015-0611-00/01 pulse head is the later version  used on the CG5010 and CG5011 calibration generators.   The primary differences between the later 0611 and earlier 0311 are:

The 0611 has faster edge rise time of <150 ps or < 160 ps for the Tegam version
The 0311 has slower edge rise time  of <200 ps
The 0611 is larger (taller) than the 0311
The 0611 made by Tegam has an SMA output connector
The 611 made by … Read More »


Tektronix 7904A S52 Pulse Response

Posted by Shaun Merrigan in Electronics, Oscilloscopes, Test Equipment. Comments Off on Tektronix 7904A S52 Pulse Response

20th August

Tektronix 7904A S52 Pulse Response

This post documents my investigations into the following vintage electronic gear:

Tektronix 7904A Mainframe (500 MHz Bandwidth)
Tektronix S52 Pulse Head (tr<25ps)
Tektronix S4 Sampling Head (tr < 25ps)
Tektronix 7S12 TDR/Sampler Plug-in

Here is the test setup:

Tektronix 7904A using 7S12 with S52 and S4 heads. 34ps system rise time. She’s working Captain (MS)

 


HP 8903B Audio Analyzer PCB Pad Replacement

Posted by Shaun Merrigan in Electronics, Test Equipment. Comments Off on HP 8903B Audio Analyzer PCB Pad Replacement

18th August

HP 8903B Audio Analyzer PCB Pad Replacement

Visual inspection of my recently acquired HP 8903B Audio Analyzer revealed that the polymer pads on the bottom side of the main PCB were seriously deteriorated:

 

HP 8903B Deteriorated Pads Overview

 

HP 8903B Deteriorated Pads Closeup

 

HP8903B Deteriorated Pad Macro Lifted

Besides making an unsightly mess, this residue may form corrosive products which, over time, could damage the PCB.  Also, the pads no longer perform their bottom cover to PCB isolation function.  So all the old pads and residue had to be removed and new pads installed.  Lintless wipes, isopropyl alcohol, and nitrile gloves were the chosen tools.

 

HP 8903B partly cleaned PCB

 

HP8903B Board Cleaned and Pads Replaced Overview

 

HP8903B Board Cleaned and Pads Replaced Macro

The residue cleaned up completely, and new pads were installed. I won’t need to … Read More »