Cpu /System Memory Inspection - Pioneer PDP-42A3HD Service Manual

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7.1.5 CPU / SYSTEM MEMORY INSPECTION

CPU /System Memory Inspection

A
Error Occurs During S/W Installation or Update through BOOTROM Board.
System Stops During Initial Booting or Operation.
Preliminary Checkpoints
If the system does not respond even though no problem was found after basic inspection,
you need to check the flash memory that contains program codes for the proper system operation,
Flash Memory Control signals that look similar to below waveforms will be repeated.
The main cause of the problems related to System Memory (i.e.Flash and DDRSDRAM)is the soldering of parts.
Therefore, first check the soldering condition and the power supply of IC.
B
C
Check CPU
and Flash Memory
(Incorrect insertion, poor
soldering, etc.)
D
OK
Re-check the basic inspection
items
E
Useful Tips
1. Check CE, OE and WE of Flash Memory when system does not operate or cannnot update for new software.
2. When the system will not operate even though the basic inspection results were normal, check Flash Memory which
contains channel data and program contents.
3. Additionally check for Local ADDRESS buses between CPU and Flash Memory.
4. Check the Memory interface of DDRSDRAM if the Flash Memory is not defected.
5. When replacing parts, be careful of static charges from the tip of the solder iron that can easily damage the parts.
Also, check for assembly condition, soldering condition, or for incorrect or reverse insertion of parts.
F
6. If the problems are caused by CPU, change CPU board and download Serial Number.
T18
94
1
2
Error Occurs During S/W
Installation or Update
through BOOTROM Board.
NG Check Flash Access
signal CE(Pin 14), OE(Pin 54)
PDP-42A3HD
2
3
Waveform 5
OK
NG
Waveform 7
Ch:DDR0A0
CH:DDR0D0
3
4
Check the Data and
Addresses of DDR-SDRAM
OK
Check for other defective
modes
T18
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