6.2DRAM Test

(1)To start up the test program:

While pressing the Switch (RESET switch), turn the power on. ”DRAM CHECK” will be displayed. Then press CONTINUE switch to start DRAM checking.

(2)The LCD will display "START DRAM TEST" and the DATA lamp or ALARM lamp will be flashing.

(3)On satisfactory completion of all the RAM test, the LCD will display: "DRAM OK!!".

(4)If any DRAM has an error, the LCD will display:

RAM address

WRITE data

READ data

The following table is the reference.

Table 6.1 Video Controller DRAM Address Corresponding Table

Address

Part replacement

 

 

 

 

 

 

Lower order

 

 

 

address

 

 

 

 

 

 

$08000000

0, 4, 8, C

#32

 

-$081FFFFF

1, 5, 9, D

#30

*1

 

2, 6, A, E

#27

 

 

3, 7, B, F

#22

 

 

 

 

 

$08200000

 

Replace with SIMM

 

-$099FFFFF

 

corresponding to

*2

 

 

memory map.

 

 

 

 

 

*1: Replace the DRAM on the Main PCB.

*2: Replace the SIMM.

Note1: There may be the case that the above sequence doesn’t work correctly according to the contents of RAM failure, or in faulty assembly such as soldering bride or ineffective soldering etc.

Note2: ”PRINT CHECK” may be displayed when getting out from TEST mode. It will disappear in 20 or 30 seconds, displaying ”READY” on LCD. It is not a trouble.

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Brother HL-1260 service manual Dram Test, Video Controller Dram Address Corresponding Table