Emax

I need some help !

I bought the Emax Plus Rack I was talking about earlier. It's a "Plus 
SE with SCSI", serial number 002 (!).
The sampler works but it has a display problem and quite a strange 
SCSI chipset:


1. The DISPLAY Problem
----------------------

First of all this machine has a problem with the LCD display. 
After pushing some buttons, the contrast on the second line goes to 
zero and the contrast on the first line goes to the maximum.
There's also an annoying high frequency noise coming from the main 
board (invertor ?) and also from the display (this only when the 
problem occurs)

Now I also have a spare Emax-II rack with a perfectly working 
frontpanel PCB board & display. 
I compared the two boards and they look almost the same:
- board in Emax Plus = 'Emax Rackpanel version 2 1986' PC328 REV B 
ASSY REV A (AF133)
- board in Emax II   = 'Emax Rackpanel version 2 1986' PC328 REV D 
(no assy)  (AF133)
The two capacitors on the board however have different numbers - 
these are actually the only two components on the board which are not 
buttons, sliders, display, lights or chip :-)

My question:
Do you think it's safe to switch these boards ? Maybe it won't work, 
that's no problem, but I just want to be sure the Emax Plus won't get 
damaged by this experiment.
Anyone who can give me some advice ???


2. The STRANGE Thing
--------------------

I also want to add an external SCSI port to the sampler. It's not 
fitted on the board, and there's no hole in the backpanel either.
Now I checked the specs from the sampler:
- it's a PC333 Rev B main board
- the SCSI 5380 chip is installed on IC6
- the IP379A HD/Plus TIM PAL chip is installed on IC49
...
- but on IC13 there's a 24-pin IP349C chip instead of the IP355 
mentioned on www.emulatorarchive.com. 
However, it is installed on an 28-pin socket. There's also an IP349 
Rev 3 'piggyback' board installed at the left of the main PC333.

This is a situation not described in the SCSI Upgrade instructions on 
www.emulatorarchive.com. 
According to the upgrade instructions either the 3 chips have to be 
installed or all 3 chips should already have been factory-installed.
If they're not installed, the IC13 should have no 28 pin socket yet. 
But mine has...
I really don't know what machine I bought, it seems like a prototype 
of the Emax Plus...

Anyway: can anyone confirm that the specs are sufficient, so that I 
just have to add a DB25 SCSI port and a flat cable ?
Or should I simply try & check ?



Thanks !!

///E-Synthesist