32,934
edits
No edit summary |
|||
Line 34: | Line 34: | ||
==Pictures== | ==Pictures== | ||
<gallery> | <gallery> | ||
Tek 432 1.jpg | |||
Tek 432 2.jpg | |||
Tek 432 3.jpg | |||
Tek_432_internal_1.jpg|This shows the area around the BNC input connectors for channels 1 and 2. This photo was taken when the owner was cleaning the vertical gain rotary switches which had become flaky after 45 years. | |||
Tek_432_internal_2.jpg|View from the rear. The vertical gain attenuator switches are under the metal covers. | |||
Tek_432_internal_3.jpg|When the metal covers are removed, one can see the shaping/compensation capacitors. These can be unplugged, each one has 6 legs. | |||
Tek_432_internal_4.jpg|Another view of the shaping capacitors. Work on one channel at a time to avoid mixing these up. Carefully clean the legs with isopropal alcohol and paper towels. | |||
Tek_432_internal_5.jpg|In order to access the rotary gain switch fingers, one must first remove these BNC connectors, which means unsoldering the central wire (connects to a resistor/inductor feed-through) plus a debouce capacitor and lead going to the x1 x10 indicator lights. | |||
Tek_432_internal_6.jpg|Close up view of BNCs | |||
Tek_432_internal_7.jpg|Close up view of BNCs | |||
Tek_432_internal_8.jpg|Close up view of BNCs. These need to be unsoldered for removal, but nothing else must be unsoldered to access/clean the vertical gain rotary switch. | |||
Tek_432_internal_9.jpg|View of the input preamp. This board needs to be unplugged only, but not removed or unsoldered. It has four 2-pin connectors. Then it can be removed, still attached to the compensation capacitor carriers. | |||
Tek_432_internal_10.jpg|Lifting off the assembly consisting of the 2 compensation capacitor carrier plus the vertical preamp board plus the push-button switch board for CH1/CHOP/ALTERNATE/CH2. The switch board has two plug connectors below that must be removed. It helps to have long fingers or a good pair of needle nose pliers. | |||
Tek_432_internal_11.jpg|Second view under the assembly being removed. | |||
Tek_432_internal_12.jpg|The rotary switches exposed. Each one has four contact fingers underneath. They are cleaned using small (5mm) wide strips of paper soaked in isopropanol alcohol (2-propanol). | |||
Tek_432_internal_13.jpg|One can just see the four contact fingers peeking out. You can get paper under them using small tweezers. Patience and calm are required. | |||
Tek_432_internal_14.jpg|A view of the variable-gain potentiometers. Note that the bodies are both cracked in the same place. Both had been noisy, but the noise was largely eliminated by sweeping them back and forth a dozen times. That may have scrubbed off the oxide. | |||
Tek_432_internal_15.jpg|A view of the contact fingers underneath the capacitor shaping blocks. Each channel has 8 NC and 8 NO fingers (the other half are on the bottom). These are easy to reach and clean as described. So each channel has a total of 20 contact fingers to clean. | |||
</gallery> | </gallery> | ||
[[Category:400 series scopes]] | [[Category:400 series scopes]] | ||
[[Category:Specifications needed]] | [[Category:Specifications needed]] |