Path: utzoo!attcan!uunet!lupine!infopiz!athertn!hpda!hpcuhb!hp-ses!hpcea!twakeman
From: twakeman@hpcea.CE.HP.COM (Teriann Wakeman)
Newsgroups: comp.sys.mac
Subject: Re: How to mount SIMMS in Mac+ ?
Message-ID: <430084@hpcea.CE.HP.COM>
Date: 27 Feb 89 19:55:29 GMT
References: <934@swisun.swivax.UUCP>
Organization: HP Corporate Engineering - Palo Alto, CA
Lines: 47

Just a suppliment to the previous how to install RAM reply.

RE: the static wrist band- This is a conductive bracelet & conductiveline
that has an allagator clip {or equiv.} at the other end.Somewhere between
the wrist band and theclip is a 1 meg resistor or equiv. The object is to
equalize the voltage potential between you & the circuit that you are working
on with a low level of current {hense the large resistance}. Dosn't matter if
you buy one or make one. You will need it as soon as you remove the enclosure.
Put the bracelet on your wrist & connect the other end to the chassis.
Once the board is removed, you will want to move the clip to a ground point
on the board, probably one of the metal flanges. Revers procedure when       
replacing board.

RE: the resistor to be clipped. The plus has coordinates marked on it.
The resistor to be clipped is R8 located at C1. It is in a white rectangle
drawn on the board. It is a 150 carbon comp resistor {colour bands brown,
green, brown, gold{5% tolerance marking}}

On a SE, the 150 ohm resistor is R35, & I believe it is located near the 
RAMS. Look for a white rectangle labled RAM size.

RE: repacing the SIMMS.  The SIMMs are latched into their sockets. There are
socket pins sticking up through holes in the SIMMs {one on each side} and
a clip arm on eather side of the SIMM holding it into the socket. What you
need to do: Carefully slide each arm of the socket off the side of the board.
the SIMM will pop up with the arms off. remove the SIMM. Lay the new SIMM
into the socket woth the SIMM holes over the socket pins & gently press
down. Clip the arms over rhe edges of the SIMM board & its in. The socket
is spring loaded with the socket pins acting as the spring. Be careful with
the arms, Force them too hard & you will need another socket. If you have
SMT SIMMs there should be no fit problems. Problems may occur with DIP
SIMMs. Here leads go through the board & are soldered on the bottom side.
The pins closest to the socket may interfere with the SIMM socket & not allow
the SIMM to fit low enough in the socket for the arms to lock. This has been
a problem with MacProducts USA SIMMs for instance.

RE: What the previous peply did not say:  Disconnect the power cord before 
opening the Mac. There are some capacitors that may pack a powerful jolt
inside the Mac. You can avoid the problem by letting it sit overnight with
the power off before opening the Mac. Otherwise, stay away from the
board on the side of the Mac.
Put the enclosure back on before turning the Mac back on unless you are an
"expert" and know what can hurt you & how to avoid it.

Best of luck!

TeriAnn