[comp.sys.mac.misc] The PMMU Socket on older Mac II's

news@excelan.COM (The News Manager) (09/15/90)

Reply-To: barrey@ka.novell.com (Barrey Jewall)
Organization: Novell, Inc., San Jose, Califonia
From: barrey@ka.excelan.com (Barrey Jewall)
Path: barrey

In article <1990Sep14.203635.12895@ccu.umanitoba.ca> umcarls9@ccu.umanitoba.ca 
(Charles Carlson) writes:

>In article <1990Sep14.005454.3917@bpdsun1.uucp> rmf@bpdsun1.UUCP 
>(Rob Finley) writes:

>>Ok.  Here is the scenario:

>>I am sitting in front of a disassembled MacII with the Motorola 68581 
>>memory management chip and I remove the fake mac chip expecting
>>to be ready for the next release of Finder, et al.

>>GAACK!
>>Where did the rest of the ic pins go in the socket?  They match the
>>fake one but not the real one... B-)

>>Aside from desoldering and replacing the WHOLE socket, how is Apple
>>planning on getting the rest of the connections to the MMU?  
>>Offer a '030 retrofit?  Swap motherboards?  Instant old computer?

>Same situation when I bought my used Mac II.  Apple offers a free board
>swap if you have that older Mac II board. <Mine was done less than 2 months
>ago so it is still valid!>   I'm not sure what Apple repair guidline it
>fell under, but keep trying dealers until you find one who is willing
>to do some digging.  Thats what I had to do.  In fact, most of the service
>techs I talked didn't even know what a PMMU was. <where do they find
>these knowledgable board swappers anyway?>  
>Oh, and don't let them tell you that you have to buy the PMMU and show them
>proof that you have it before they do the swap.
>It was nice buying a 3 year old Mac II on the used market and getting
>a new motherboard put in it.


>Charles

Here's the scoop, from the horse's mouth, so to speak...

MACINTOSH II HMMU/PMMU SOCKET UPGRADE--OMR2560
(Announced August 89)
 
OVERVIEW
A limited number of Macintosh II CPUs were manufactured with an HMMU-unique
socket that does not allow the CPU to function properly if a PMMU upgrade is
installed.  Customers who install a Finished Goods PMMU Upgrade Kit in a
Macintosh II with an HMMU-unique socket are entitled to a Macintosh II Logic
Board exchange at no cost.
 
HOW TO IDENTIFY AN HMMU SOCKET
To identify whether the system contains an HMMU-unique socket, look at the
underside of the Macintosh II Logic Board.  (Refer to your Module
Identification manual for the location of the HMMU/PMMU on the Macintosh II
Logic Board.)
 
* HMMU sockets, which accommodate HMMUs only, contain 70 gold contacts soldered
  through the board in a random pattern.
 
* HMMU/PMMU sockets, which accommodate either component, contain 132 gold
  contacts in a 13 by 13 pin pattern.
 
When a PMMU upgrade is installed in a Macintosh II CPU containing an
HMMU-unique socket, many pins do not connect and the system will not boot.
 
REPAIR EXTENSION AUTHORIZATION
To obtain Labor, Parts Credit, and Parts Margin reimbursement,* return the
Macintosh II Logic Board to Apple and record the part number on the SRO form.
In addition, record the repair extension authorization code "OMR2560" in the
Warranty Information section of the SRO.
 
If a logic board with an HMMU-unique socket is covered by AppleCare and meets
the criteria for this program, list the exchange transaction under the Repair
Extension Program on the SRO, not under AppleCare.

That number is what Apple Dealers need to get paid for the exchange...

(OMR2560)

Good Luck- Barrey

--
+ Barrey Jewall                 ++ "My opinions are my opinions" +
+ barrey@novell.com	        ++ (rather self-evident, eh?)    +
+ Novell, Inc.- San Jose, Calif.++				 +