A recent post to the Fender Forums (see: http://forums.fender.com/viewtopic.php?f=27&t=100594) contains several links to PDF's purportedly of the Fender Mustang Schematics.
Hi all,
This is my first post in Fender Forums.
I'm a 5 year owner of a Strato American Deluxe HSS, and I just purchased a Mustang IV (V.2).
In the urge of finding out the most about this awesome amplifier I came across a lot of users wanting to access the schematics of their amplifiers. Having an Electrical Engineering degree and being curious as hell, I began searching those around, and after doing some advanced Google searching I stumbled upon these:
Mustang V: http://www.fmicassets.com/Damroot/Original/10001/2300500_gamp_schematic.pdf
Mustang IV: http://www.fmicassets.com/Damroot/Original/10001/2300400_gamp_schematic.pdf
Mustang III: http://www.fmicassets.com/Damroot/Original/10001/2300300_gamp_schematic.pdf
Mustang I & II: http://www.fmicassets.com/Damroot/Original/10001/2300200_gamp_schematic.pdf
Mustang Mini: http://www.fmicassets.com/Damroot/Original/10001/230006_gamp_schematic.pdf
Mustang Floor: http://www.fmicassets.com/Damroot/Original/10001/2301060_gamp_schematic.pdf
They appear to be legit, but of course I can't tell it for sure.
Disclaimer: I'm not responsible for these files neither I have control over their availability. They are publicly available through a Google link resulting from a trivial search string.