Failure Analysis Of Dsp, Flash Rom And Ram (Base Unit) - Panasonic KX-TGP500B04 Service Manual

KX-TGP500B04/KX-TPA50B04

10.2. Failure Analysis of DSP, FLASH ROM and RAM (Base Unit)

It is difficult to find the defective parts causing operation failure in this unit because DSP, FLASH ROM and RAM are connected
to the same bus line.
This unit has two ports as the means to watch the operation of DSP, FLASH ROM, RAM, etc. during the start-up process. The
following conditions can be confirmed with these two ports.
1. The FLASH ROM in which the Program is written is working correctly.
2. RAM is working correctly.
3. The Boot of DSP is working correctly.
4. Being connected to another Bus line, the FLASH ROM in which Data is written is working correctly.
The operation from turning ON to the final judgment with a normal unit is given below.
OK Waveform
Note:
(*1) Refer to Circuit Board (Base Unit_Main) (P.113).
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