Brother HL-2700CN Series, Service Manual

Page: 133 / 377

V-8
2.3 DRAM Test Mode
This mode tests DIMMs installed on the main (video controller) PCB.
<Procedure>
1) To start the test program:
While holding down the Go key and + key, turn on the power. “DRAM CHECK
START” will be displayed. Press the Job Cancel key to start the DRAM check.
2) The LCD will display “START DRAM TEST”.
3) On satisfactory completion of all the RAM tests, the LCD will display: “DRAM OK!!”
4) If any DRAM error has occurred, the LCD will display a fail message as follows;
5) Enter the hidden menu mode as follows to confirm the current memory map;
i) Press the -, + and Set keys in this order while holding down the Go key.
ii) The LCD will display “HIDDEN PANEL”
iii) Select the “DRAM ADDRESS” menu using the Back and + keys.
iv) Whenever the Set key is pressed, the LCD will display the DRAM error
address on Slot 1.
6) If a DIMM DRAM has an error, replace the DIMM corresponding to the above
memory map information.
Note:
•
There may be a case where the above sequence does not work correctly due to
complete RAM failure, or in faulty assembly such as a solder bridge or ineffective
soldering etc.
•
“PRINT CHECK” may be displayed when exiting from the Test mode. It will disappear
in 20 or 30 seconds, displaying “READY” on the LCD. It is not a fault.
RAM Address
WRITE data
READ data