Tektronix 2465 Input Issues

[mawyatt]

Hello,

New here and thought about posting a success repair for restoring the Input functions on channel 1 and 2. I purchased a couple 2465 off eBay, each had their problems. I've replaced many of the usual power supply capacitors (waiting for a few others) as indicated by many others. Both channels 1 and 2 had multiple problems with ground erratic and not working, 50 ohms, range and such. After some study of the schematics and single tracing the problems were localized to the 2 input hybrid modules. Replacements were expensive, even in surplus removed from trashed scopes, so decided to try and repair the hybrid.

These were removed and disassembled (use a heat controlled soldering iron on the hybrids as it's easy to "leach" the surface and ruin the hybrid), everything seemed OK except the ceramic hybrid relay contacts were suspect. These modules use the substrate as the contact area for the input open type relays. Evidently these contact areas were oxidized and maybe coated with something, possibly tobacco smoke. Used a rubber soft pencil eraser to carefully clean the contact area, then thoroughly clean any residue.

After hybrid reassembly and reinstalled the 2465 has now be revived and back to proper working order, beautiful scope !!!

Note: Bottom image should be at top.

Best,


Mike

[BravoV]

Wow .. thanks for sharing this, really appreciate it. 

[mawyatt]

Hopefully this will help some folks, and they won't need to replace the input hybrids. Believe these hybrids are used in a few different scopes.

Best,

Mike

[jdragoset]

Also very applicable  to earlier cam-operated contacts used in vertical input attenuators in 2235's and others.
Not at all easily accessed but do-able, with patience.
Almost like working on a Jeager, Atmos clock.