Otari MX 5050 B II HD, PREAMP ASSEMBLY BOARD#PB9A168C

[freeeflow]

I have a Quick Question and hoping you might be able to point me in the right direction.
I've read every forum and just can't find the details.

Scenario
- I've inherited reels of my musician Father and bought an Otari to get everything digitized for legacy/posterity
- the reapir shop i'm using is awesome and skilled with repairs but cant find the schematic or service manual which includes the "PREAMP ASSEMBLY BOARD#PB9A168C ".
* we have them for the Otari MX5050 BII HD, BUT they never include this part number 8-( http://www.tubesrit.com/audio/thumbnails.php?album=14

Question
- do you know where i can find the schematic or user manual with the specific "PREAMP ASSEMBLY BOARD#PB9A168C " included?

[Listens2tubes]

I'll try to dig into my BII-HD to see if the board matches.