Chapter 6 Troubleshooting; Diagnostics; Overview - Lexicon 960L Service Manual

Chapter 6 Trou b leshooting
Check the Lexicon web site and Customer Support Knowledgebase for the latest software and information:
http://www.lexicon.com
http://www.lexicon.com/kbase/kbase.asp

Diagnostics

Overview

The purpose of this document is to describe the diagnostic tests in the 960L. The diagnostics in the 960L
are utilized to verify performance and functionality. The 960L and LARC2 are a high end, digital audio
effects system. The 960L and LARC2 system is a multi-channel digital audio effects processor that can also
be configured as a single channel processor. The LARC2 provides full control of 960L through a 50-foot, 9-
pin cable. The 960L and LARC2 system is composed of the following printed circuit assemblies
manufactured by Lexicon:
1. NLX backplane
2. I/O backplane
3. I/O Clock
4. Analog In
5. Analog Out
6. Reverb
7. AES
8. LARC2 Main
9. LARC2 Meter.
In addition there are 6 OEM devices:
1. NLX PC processor card (motherboard) with Celeron CPU Processor
2. NLX/ATX power supply
3. 3.5" floppy drive
4. CD-ROM
5. MIDI Card
6. Hard Disk Drive
960L Diagnostics:
The 960L has 3 sets of diagnostics, power on, functional, and troubleshooting. The power on diagnostics
are executed every time the 960L is powered on. The power on diagnostics verify basic reverb card
functionality, checks which cards are present in the I/O cage and communicates with the LARC2.
The functional diagnostics are used to verify the performance of the digital circuitry of the 960L. The
functional diagnostics test the following:
1. MIDI port
2. Serial 2 Port
3. Reverb Card, which includes
a. 56301 to Dual Port Ram
b. Z80 to Dual Port Ram
c. Z80 to DRAM
d. Z80 to SRAM
e. Lexichip3 WCS, (Writeable Control Storage)
f. Lexichip3 ADF, (Audio Data File)
g. TMIX
h. Serial Audio, (all the Octal Audio Data lines)
Lexicon
6-1