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7L5/Repairs: Difference between revisions
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=Intermittent | =Intermittent Rotary Encoder= | ||
The "Dot Frequency" and "Reference Level" rotary encoders can become faulty so that they either do not work at all or just cause random unpredictable changes when operated. The good news is that they are mechanical switches constructed from hard gold contact traces on the front panel PCB, and all elements are held together by screws. They can be accessed by separating the front panel from the 7L5 and removing the front panel overlay. Simply cleaning the gold traces on the PCBs with isopropyl alcohol and carefully bending the contact fingers slightly outward to reestablish contact force will restore operation. See the figures below. | |||
=Front Panel Disassembly= | =Front Panel Disassembly= | ||
to | The [[7L5]] is constructed of two main modules and the front panel assembly. The left module hinges outwards once a few screws are removed, and with further screw removal the complete front panel assembly comes off. When further disassembling the front panel not the unconventional "Frequency Span" and "Time/Div" switches. These are entirely build into the respectable knobs and can be pulled off from the front panel after removing two fasteners at the back. Note that the "Time/Div" switch has very thin metal contact fingers that fit into a socket on the front panel PCB. To guide installation there is a little plastic spacer with conical holes for those pins. Make sure to install this spacer in the right orientation before attempting to reinstall the "Time/Div" switch. | ||
=Pictures= | =Pictures= | ||
==Front Panel== | ==Front Panel== | ||
<gallery> | <gallery> | ||