Lexicon MPX 110 - LED Test (10); Lexichip3 External DRAM Test (11)

MPX 110 Service Manual
5-14
mode or from the PC's command line.
LED TEST (10)
This test will verify all LED’s (8) are working. When selected, the Binary LED’s will read the following:
Edit Bypass Store Tap
O O O l
MSB LSB
Pressing the STORE button will execute the test.
When the test is executed, the Front Panel LED’s that are assigned to the current position of the
PROGRAM Encoder will be lit. (See below)
PROGRAM Encoder
Position
LED Assignment
Plate, Gate All LED’s On
Hall, Chamber Left Clip On
Ambience, Room Right Clip On
Tremelo, Rotary Left Level On
Chorus, Flange Right Level On
Pitch, Detune Edit On
Delay, Echo Bypass On
Special FX Store On
User Tap On
Flange - Delay All LED’s Off
Pitch - Delay All LED’s Off
Chorus - Delay All LED’s Off
Delay - Reverb All LED’s Off
Flange - Reverb All LED’s Off
Pitch - Reverb All LED’s Off
Chorus - Reverb All LED’s Off
The STORE button will be active to exit the test. The PROGRAM Encoder will be active to test the LED’s.
Referring to Table 2, each LED is assigned to a position on the PROGRAM Encoder. When a position is
selected, its assigned LED will light. There's also a position where all the LED’s will light and a position
where all LED’s are off.
When the test is executed the VARIATION Encoder, BYPASS, TAP, ADC Pots and footswitches (2) are
inactive.
LEXICHIP3 EXTERNAL DRAM TEST (11)
The DRAM test is a modified checksum test executed by the Lexichip3, and is designed to exercise all 24
of the DRAM data bits. During the test, a unique value is written into each memory location, a modified
checksum which alternately adds or subtracts successive values is then calculated and stored in the
Lexichip3’s ADF. The checksum calculated from all the DRAM memory locations is then compared with the
checksum stored in the Lexichip3’s ADF. The test passes if the DRAM checksum equals what is stored in
the Lexichip3’s ADF. The DRAM test takes approximately 12 seconds to complete.
Note: Interrupts are disabled during the test which effect the normal operation of the Front Panel LED’s.
The Front Panel LED’s will return to normal operation when the test is completed and the pass/fail result is
displayed.
When selected, the Binary LED’s will read the following: