[sdiy] Name this part (Or: got a MPC3000 service manual?)

[Jeff Farr]

I've finally got the time this weekend to get my MPC3000 opened up and
get a good look inside to find out why it died back in July.  I've
checked out the PSU and all the voltages look fine, +-12v, 5v, 9v are
all there.  It seems now to be a problem with the power supply that
feeds the LCD screen, which no longer turns on at all which isn't a
suprise given that there is no voltage being fed to it.  However, the
setup for feeding the LCD is not so simple, the 5v comes off the PSU
onto the PCB with the MCU's and MIDI interface on it and is then sent
off along with -12v to the contrast control before returning to the
PSU board where it appears that there is a big honkin' regulator there
before it finally gets fed back to the LCD.  This doesn't make a whole
lot of sense to me, but that is what I see.  Can someone tell me if
this thing is in fact a regulator?  It's got 3 pins, wired up like a
input/common/output and it's got 5v being fed to it, nothing coming
out.

http://i136.photobucket.com/albums/q187/smeffasystems/MPC020.jpg