MiTAC 7521 PLUS/N User Manual

116

Either on board or extend SDRAM is failure or system hangs up.

MEMORY TEST ERROR

1. Check if on board SDRAM  chips are no cold  

solder.

2. Check  the extend SDRAM  module is installed 

properly. (

J6

)

3. Confirm the SDRAM socket is ok, no band 

pins.

Test

OK?

YES

NO

Try another known good 
SDRAM modules.

Correct it.

END

YES

NO

Replace mother
board or into
board level
Troubleshooting.

Board-level

Troubleshooting for

Memory test error.

Check the following parts for cold solder or one of the following 
parts on the mother-board may be defective, use an oscilloscope
to check the following signal or replace the parts one at a time and 
test after each replacement.

Parts:

U24, U15
U18, U22
U25, U29
U19, U23
U26, U30
RP20, RP22
RP23, RP25
RP41, RP44
RP54, RP53
RP40, J6
R588, U508

Signals:

MDR[0~63]
MD[0~63]
MAB#[0~9]
MAB[10,13]
MAB#[11,12]
SCASA#, 
SRASA#
WEA#
DQMA#[0:7]

CSA#[0:3]
CKE[0:3]
SDRAMCLK[0:3]
SMBDATA
SMBCLK

Test

OK?