Lexicon MPX G2 Service Manual

Lexicon
5-3
Press the Store Button, which will start a walking 1’s pattern that is applied to the Address and Data
busses of the CPU to help in troubleshooting the problem.
4WCS Test:
This test verifies the program memory space of the Lexichip-2 (U85) is working. The memory space is first
filled with the value 55 hex (1010 1010 binary), and then each memory location is read back to see if it
contains the 55hex value. If 55 hex is read back, the memory is then filled with AA hex (1010 1010 binary)
and the test is repeated. It is then filled with 0’s and repeated again. Upon completion, an address test
verifies all address lines are active and the memory is filled with 0’s.
Before the test is executed, a 4 is displayed in the rightmost 7-segment display on the MPX G2.
If a failure occurs, an E is then displayed in the leftmost 7-segment display along with the 4 on the MPX G2,
indicating an Error E 4 has occurred.
If an error occurs, there are two options:
Press the Program Button on the front panel to continue the Power On Diagnostics sequence.
or
Press the Store Button, which will start a walking 1’s pattern that is applied to the Address and Data
busses of the CPU to help in troubleshooting the problem.
5 2186 SRAM Test:
This test will verify the memory spaces of the ADSP2186 (U88) and SRAM (U89). The memory space is
first filled with the value 55 hex ( 1010 1010 binary ), then each memory location is read back to see if is
contains the 55hex. If 55 hex is read back, the memory is then filled with AA hex (1010 1010 binary) and
the test is repeated, it is then filled with 0’s and repeated again. On it completion an address test verifies all
address lines are active and the memory is filled with 0’s. The address range for this test is 2000-27FF.
Before the test is executed, a 5 is displayed in the rightmost 7-segment display on the MPX G2.
If a failure occurs, an E is then displayed in the leftmost 7-segment display along with the 5 on the MPX G2,
indicating an Error E 5 has occurred. The display will also read the following:
2186 SRAM Test Failed
If an error occurs, there are two options:
Press the Program Button on the front panel to continue the Power On Diagnostics sequence.
or
Press the Store Button, which will start a walking 1’s pattern that is applied to the Address and Data
busses of the CPU to help in troubleshooting the problem.
6 Lex-2186 Test:
This test will verify that the serial audio communication between the ADSP2186 U88 and the Lexichip U85
is working. The ADSP2186 sends a value to the Lexichip then reads the value back and then verifies the
data it sent is what it received back. The Lexichip is loaded with an I/O program that feeds the value it
receives back to the ADSP2186 unprocessed.
Before the test is executed, a 6 is displayed in the rightmost 7-segment display on the MPX G2.
If a failure occurs, an E is then displayed in the leftmost 7-segment display along with the 6 on the MPX G2,
indicating an Error E 6 has occurred. The display will also read the following:
Lex-2186 Test
Failed
If an error occurs, there are two options:

Lexicon MPX G2 Specifications

General

Brand	Lexicon
Model	MPX G2
Category	Recording Equipment
Language	English