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Resolving Keyboard Issues on the Sony ICF-SW7600GR

The Sony ICF-SW7600GR , a well-known portable shortwave receiver, has built a solid reputation for its performance and reliability. I purchased this receiver 20 years ago, and it is likely the last portable shortwave receiver manufactured by Sony . I primarily use it for shortwave listening, and it has functioned continuously for two decades. However, like all electronic devices, it is subject to component degradation over time. This post outlines the diagnostic and restorative procedures I undertook to address a complete failure of the keypad on this radio. Restored ICF-SW7600GR radio. Initially, the radio exhibited a gradual decline in keypad functionality, which eventually led to a complete lack of response. I observed intermittent key input before all keypad operations ceased entirely. This symptom suggested a possible discontinuity or short circuit within the keypad interface circuitry. To investigate further, I disassembled the unit to inspect the internal components. My p...

Network cable tester

This is an automatic Cat6 / Cat5 network cable tester designed using NE555 timer and 4017, decade counters. This unit test all 8 wire lines of twisted pair network cable and indicate pass/fail status with a single LED. We design this unit to test network connectivity issues in Cat6 / Cat5 cable systems and it is capable to check both crossover and straight-through type network cables. A prototype version of network cable tester. The recommended way to construct this circuit is on PCB. Both Master and Salve units need to be built on two separate boards. To perform test one end of the network cable must be connected to the Master unit and other ends need to be connected to the Slave unit. After connecting both Master and Slave units press " START-TEST " (S1) button to perform the test. Status of the cable is indicated through LED2 ( PASS indicator). PCB and schematic of this unit are available to download at google drive and easyeda.com .