Lexicon MC-1, Service Manual

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Lexicon
5-1
Chapter 5 Trou b leshooting
Check the Lexicon web site for the latest software and information:
http://www.lexicon.com
The Lexicon Home Theater Products downloads page:
http://www.lexicon.com/downloads/ht_index.html
The Lexicon Support Knowledgebase:
http://www.lexicon.com/kbase/index.asp
V4 Release Notes
The MC1 software has been updated to V4 which includes Surround EX. This is a list of the bugs that were
fixed in V1.1 which have carried forward to V4.
V1.00 bug descriptions:
1. Decorrelation does not work in AC3 THX 5.
2. Right rear output sometimes mutes in DTS THX 5.1.
3. Video signal bleedthrough when in Standby with SECAM Format selected.
4. Bass levels are too loud in Music Surround, Music Logic and TV Matrix effects.
5. The Bass Enhance parameter clicks when turning it on or off and may overload in the right front channel.
6. The Side Rolloff and Rear Rolloff parameters do not work in the Music Surround effect. They have been
replaced by one Surround Rolloff parameter.
7. The Center Bass Split crossover frequency points are too high, causing low frequency information to leak
into the Front Left and Right speakers in AC3 effects.
8. The Auto Azimuth parameter is not working in Logic7 and TV Matrix effects.
9. The level meters are not working correctly in AC3 and DTS effects.
Diagnostics
There are two sets of MC-1 Diagnostics: Power On Diagnostics, and Extended Diagnostics. The Power On
Diagnostics are automatically executed each time power is applied to the MC-1 via the rear panel power
switch. Extended Diagnostics are not automatically executed, but can be invoked by the user for specific
purposes. Extended Diagnostics include additional tests to verify front panel controls, inferred
communications, and audio and video performances, as well as those used to troubleshoot the MC-1.
In normal use, the MC-1 is left connected to AC power and its operation is controlled by the front panel
ON/STANDBY button or by the remote control. When controlled this way, Power On Diagnostics are not
executed.
Diagnostic Reporting
All diagnostics functionality is reported to the front panel Vacuum Fluorescent Display, and to the front
panels LEDs. These identify the test being executed, and pass and failure information. The LEDs are
utilized to report diagnostic status in the event that the VFD is not functioning. More information is available
on the diagnostic reporting operation of the VFD and the front panel LEDs in the VFD display, and front
panel LEDs section.
In the event of diagnostic failure, additional information, such as data sent, data received, address location
etc, is listed in an error log can be found in the Error Log.
Diagnostic status and data is also available to a external PC or terminal, via the Serial Port Debug Port
(RS232) on the rear panel of the MC-1.