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IT Question - old Monitor problem - LISA


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OK - I have been going through a bunch of old stuff I have … and repacking some - tossing others and just trying to organize.  I have an Apple Lisa .. and the last time I was dinking around with it (started it up) before I put it into storage the last time… I had a monitor problem.  This is a small like 9" (guess) monitor (b/w old pre-mac basically).  The OS is fine but the monitor is "rolling" or not coming into focus right.  Like an old TV where it would show like 2-3 copies of the same image…?  Anyhow only the one image is right… because I poked around at icons with the mouse and I figured that much out.


ANYHOW - I am not IT techie… I don't know what this issue is really.  Is it a bad monitor… a bad card/controller or something else?


The Lisa is in great shape otherwise ( I got it from the original owner about 15 years ago).  I have the external HD.. and printer that came with it as a set.  My current idea is to rip the monitor out… and put in an LCD - and either mini mac hardware (running a flavor of linux) or even an iPad lol.  Maybe something else… there is plenty of room in the box.  But having seen some of these Lisa's go for 10's of thousands of $ on ebay from time to time - I had thought about possibly selling it at some point if it was fully operational.


Anyhow - anyone have a clue as to where to start with this monitor issue?  … or should I just remove it… and hack the box?




ps. here is a Lisa… 




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+1 for DC's warning.  CRT (Cathode Ray Tubes) depend on a series of capacitors that can retain dangerous charges (like kick you across the room with your own body spasm kind of dangerous).  There is a specific component on the board for the monitor that controls the vertical hold.  Some monitors will actually have a small dial that can be used for V.hold adjustment, called a Variable Resistor Pot or Trimpot.  Sometimes this dial is externally adjustable, sometimes not.  Aside from the adjustment, the replacement of the Vertical Output Integrated Circuit would be a possible solution to the rolling screen issue.   


Looking a little deeper, Apple did not provide the part number for the VO IC in the LISA service guide, and generally recommends the replacement of entire boards/assemblies, rather than individual component repairs.  


Lisa Troubleshooting Guide Rev. 1-6-84:




Blurred screen:

Adjust focus

Unable to adjust focus:

Replace power supply
Replace videoboard
Replace CRT
Check connections
Replace flyback

Rolling screen:

Adjust vertical hold

Unable to adjust vertical hold
(Picture keeps flipping or will
not flip at all):

Replace videoboard
Replace CPU board
Replace I/O board
Replace motherboard


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well after a bit of clean up - and letting things warm up in the room.  I plugged it in to see how it faired in storage ( I moved it 2 weeks ago)... and well... nothing.  It sounds to be coming on - then failed in a few seconds.  I unplugged it and clean it up some more.  The monitor seems to be out at this point... and I think the power supply as well.  I think the last time I was messing with it - it was just starting to go ... and at this point its probably done gone.  


So...  now I will just store it until I get a chance to hack/mod it.  Pulling out what I can to make room for something small without having to take out too much.  But that means I will have to replace the monitor with possibly an LCD.  The screen is right around 11" dia.  I think a iPad size screen would fit nicely.  But I would like it to be more than and iPad dock.  lol.  I will take extra care when I remove the monitor.  Any ideas how best to go about removing a CRT?  at least as far as de-energizing it?



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  Any ideas how best to go about removing a CRT?  at least as far as de-energizing it?




Not sure what it says about me, but this is one of the scariest tasks I've ever done on the job.  It's frighteningly simple, but I'd hate to relay in a post form, and I'm not sure I'd actually follow my own advice at this point.  :)  There are specific tools and procedures that can be researched and used to do it safely, it is not hard to do, and it's over in less than a second.  Also, see rule #1.



This is from section 3.5 in the manual linked above, kids, don't try this at home, or at work:  I forgot about the imploding part!



CRT Safety Rules


1. Do not work on a monitor alone.


In case of accident, it could save your life to have

someone else nearby. Apple recommends that your staff

be trained in Cardio-Pulmonary Resuscitation (CPR).


2. Remove rings, watches, bracelets, hanging necklaces, and

other jewelry before performing repairs on a monitor.


Metal jewelry is an excellent conductor of electricity.

Removing jewelry will reduce the possibility of electric

shock .


3. Never use a grounding wriststrap or heelstrap or work on

a grounded workbench mat when discharging a monitor or

when performing live adjustments.


Grounding wriststraps, heelstraps, and mats are used to

protect sensitive components from the damaging effects

of electrostatic discharge from your own body or

clothing. Even though they contain a one-megohm

resistor and are designed to conduct only small

electrical charges, we recommend that they be used only

when working on "dead" (uncharged) equipment.


4. Wear safety goggles when working with a CRT.


The CRT contains a high vacuum. If cracked or broken,

it can implode (collapse into itself, then explode). To

protect your eyes from serious injury, always wear

safety goggles when working on or near a CRT, and be

careful of other people in the area.


5. Before working inside a monitor, turn off the power and

disconnect the AC power cord.


Certain parts of a monitor chassis are hot (electrified)

when the monitor is under power. Except when you must

have the power on (for example, when making live

adjustments}, never work on a plugged-in monitor--even

if you have the power turned off .


6 . Keep one hand in your pocket or behind your back when

working on a live monitor.


This practice reduces the risk of current passing

through your heart, should you accidentally contact high

voltage .




Lisa 2 Video Take-Apart rev. Jun 87 page 3.3




7. Always discharge the anode before touching anything

inside the monitor.


The anode of the CRT maintains a charge of about 15,000

volts DC {even when the power is off). Before touching

any internal components you must discharge this voltage.

The anode can regain some charge, even after it has been

discharged. If the service procedure takes more than 30

minutes, the anode should be discharged again.


8. Never touch the anode connector or the anode aperture.


Normally the anode aperture has a connector plugged into

it (Figure 1, #2). When a CRT is replaced, the anode

connector is removed, exposing the anode. The anode can

maintain a charge of several thousand volts (even after

the power is of f ) .


9. Do not pick up or handle a CRT by its neck.


To prevent an implosion, take every precaution against

breaking the tube. Be especially careful with the neck,

the area where the tube is the thinnest.

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ok - well thats why I have never done it … LOL - I think I will move forward and just store the Lisa for another year or three.. as a conversation starter lol.  After I get a plan about EXACTLY what I will be doing with it (mod in something) then I will probably seek help LOL.


thanks again!



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