Shaun Merrigan's Information Pages

Tag: HP3562A

HP 3562A CRT Replacement

Posted by Shaun Merrigan in Electronics, Oscilloscopes, Test Equipment. Comments Off on HP 3562A CRT Replacement

28th December

Based on my own observations and reading, the CRT in the HP 3562A is a marvelous piece of engineering. However, it literally fatigues over time and at some point the deterioration cannot be compensated for by the range of adjustments. The solution is to replace the ageing CRT display with a modern LCD. It turns out that SimmConn Labs has such a kit:

Terry at D-Lab Electronics did a good video on how to replace the original CRT with the LCD Kit from NewScope:

Terry does a great job of documenting the replacement process, so I will focus on the before/after results. I will start with original CRT images, followed by LCD images and by split screen comparison images. Since I also purchased the RGB to VGA adapter cable from SimmConn, I will conclude with an … Read More »

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 »