2. IC-746 LCD back-light repair
My main rig is IC-746. Its LCD display back-light went off last summer, possibly by aging. After a month or so period of repeating on and off, it went off completely.

How to repair it was seen in two web sites, one locally and the other in US. Though I had considered the replacement of a cold cathode lamp, both of them reported that the failed part was not in the lamp but in a transistor to supply voltage to it. Although the disassembly process looked too complicated to me, I proceeded the works by closely following the web informaiton.

1.
The picture shows the IC-746 with its casings and front panel removed.
This look itself was sufficient to let me think of the failed repair.


2.
The picture indicates the front panel and the circuit board just behind it.
At the back of the circuit board, there exists the inverter circuit housed in a metal box for shielding.


3.

Though the transistor in question is said for power supply, it is astonishingly small, about 5 mm in width. It was retrieved immediately at a first touch of soldering iron. It might have been separeted already from the board by heat.

The original transistor was mounted directly on the board. While, the replacement transistor is larger in size, and its better colling is essential. And it was to be fixed to a wall of the metal box by a screw.

Thus the drilling of 3-mm dia hole on the metal wall was required. After putting some heat dissipation silicon grease, the replacement transitor was fixed to the wall. That is all.

4.
The rig worked fine ever after.
The end.

Expenses:
Transistor　Toshiba 2SB1015A-Y: 　105 yen
Ferrite core FT-23-43: 　53 yen x 2 = 106 yen
Total: 211 yen