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KX-MB2061CXB/KX-MB2061CX2/KX-MB2062CXB
This may be repaired by replacing the IC, (DRAM etc.). However, the real cause may not have been an IC malfunction but a sol-
dering fault instead.
Soldering faults difficult to detect with the naked eye are common, particularly for ASIC and RA (Resistor Array). But if you have
an oscilloscope, you can easily determine the problem site or IC malfunction by checking the main signal lines.
Even if you don't have such a measuring instrument, by checking each main signal line and resoldering it, in many cases the
problem will be resolved.
An explanation of the main signals (for booting up the unit) is presented below.
What are the main signals for booting up the unit?
Please refer to General Block Diagram (P.14).
The ASIC (IC300) controls all the other digital ICs. When the power is turned on, the ASIC retrieves the operation code stored in
the ROM (IC402), then follows the instructions for controlling each IC. All ICs have some inner registers that are assigned to a
certain address.
It is the address bus by which the ASIC designates the location inside each IC. And the data bus reads or writes the data in
order to transmit the instructions from the ASIC to the ICs.
These signal lines are all controlled by voltages of 3.3V (H) or 0V (L).
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Troubleshooting
