Dram Test - Brother HL 2060 - B/W Laser Printer Service Manual

6.2

DRAM Test

(1) To start up the test program:
While pressing the
"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:
(5) Enter the hidden menu mode as follows to confirm the current memory map;
i) Press the Form Feed, Mode and Continue buttons at the same time in the off-
line status.
ii) The LCD will display "HIDDEN PANEL"
iii) Select the "DRAM ADDRESS" menu using the scroll buttons.
iv) Whenever the Set button is pressed, the LCD will display the DRAM error
address on the Main PCB, Slot 1 and Slot 2 in turn.
(6) If a SIMM DRAM has an error, replace the SIMM corresponding to the above
memory map information.
If the DRAM on the Main PCB has an error, replace referring to the table below;
Table 6.1 Video Controller DRAM Address Corresponding Table
Lower order address
0, 4, 8, C
1, 5, 9, D
2, 6, A, E
3, 7, B, F
*1: Replace the DRAM on the Main PCB.
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.
Switch (RESET switch), turn the power on.
RAM address
VI-25
WRITE data
DRAM chip to be replaced
#30, 31
#16, 17
READ data
*1