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View Full Version : Apple IIGS monitor compatability



sirpaul484
November 15th, 2007, 12:39 PM
Greetings. I have an Apple IIGS, with a monitor which is crapped out. I have recently noticed that the monitor I got recently with an older (pre-imac) Macintosh fits into the GS's video port. I tried hooking it up, though, and the display I got was completely garbled. Is that due to incompatability with the monitor, problems with the monitor (I noticed that the monitor I got with the GS used to do the same thing if the vertical height was way off), or what? Thanks for the advice.

magnusfalkirk
November 15th, 2007, 04:28 PM
Greetings. I have an Apple IIGS, with a monitor which is crapped out. I have recently noticed that the monitor I got recently with an older (pre-imac) Macintosh fits into the GS's video port. I tried hooking it up, though, and the display I got was completely garbled. Is that due to incompatability with the monitor, problems with the monitor (I noticed that the monitor I got with the GS used to do the same thing if the vertical height was way off), or what? Thanks for the advice.

Greetings,

The problem is that the IIGS is incompatible with the Mac monitor. The signal that the GS sends out the RGB port is an analog RGB, if I remember correctly. You'll either need to get your current monitor repaired or find another GS monitor or one of a few others that will work with the GS.

In fact here's a part of a FAQ relating to monitors for the GS:

015- Which monitors and adapters can I use to replace my IIgs monitor?

You should keep an eye out for any analog RGB monitor that can horizontally sync down to 15.75 kHz. These include:

AppleColor RGB Monitor replacement (model A2M6014, the IIgs monitor)
Commodore 1084 models and equivalents like the Magnavox Professional 80
Sony CPD 1302 MultiSynch
NEC MultiSync (original), MultiSync II, MultiSync 3D
Commodore 1902 (although most of these only do digital RGB)
Tandy CM-8 (not sure about model but it was used with the Coco3)
Atari SC1224 (used with the ST series)
Some TVs

For example, I just tried a Sony CPD 1302 multisych monitor on a GS and it works perfectly; and it has a .25 dot pixel! Very crisp picture. I used a standard cable from a Mac II (or you could check with Redmond Cable at http://www.redcab.com/ ).

The NEC MultiSync II is another excellent monitor that will sync down to 15 kHz.

The Atari SC1224 used with the ST is a ~15 kHz monitor. There were several versions, one by Goldstar, which appeared in one of the two case styles used by Atari over the years and bore the Atari logo. It works fine with the IIgs, provided an adapter cable is created. Redmond Cable can provide it.

The Commodore Amiga 1084 monitors and Magnavox equivalents (e.g. Professional 80, 8CM515) will work with the Apple IIgs.




Hope this helps,
Dean

sirpaul484
November 15th, 2007, 05:01 PM
hmm... I'll consider getting one of those adapters. If it doesn't work with the GS, then it would more than likely work with my macintosh.

Anyways, the GS monitor isn't COMPLETELY busted, I still get a signal, it is just extremely dim, even with the brightness and contrast maxed out. Do you think there is a chance I can fix it without it killing me?

Geo3
November 16th, 2007, 06:09 AM
Hi,
Yes there may be a way to fix it. or an Adjustment the will last for awhile until it drifts. Later I plan to try to fix a few with pictures problems. You can brighent the picture and sharpen the focus, from inturnal controls. But it will probably drift out over time. I did one, set the side controls in the center, then adjusted the inside controls. It took a few hours to drift to being to bright. I test things that I sell so they do not go bad if I can help it.

First it is dangerious. There are high voltages, even with it off. I and Vintage Computers assume no responability if you or anybody gets killed or hurt. Do at your own RISK!

That said, first you want to open it up. You need a place to work that free of people, kids and pets. With a bit of room. Lay the monitor down screen down (soft are folded towel carpet) remove the screw. put them is a safe place (paper cup). Now as you pull it apart you will have to diconnect the side controls, then remove the case. Then remove the side controls from the case.

Next mark and take pictures of the brightness and focus controls. I took some pictures of these. I planned doing a write up with pictures and everthing. But have too many other things going on. But I still want to do it. Email me and I will send you the pictures of these controls.
After marking taking a picture of the settings, then make a notation of how they are set. That is are they at, 2 O Clock or whatever. So that you can put them back to orignals if it does not work out.
You will need to have all plastic screw driver or tool for making any adjustments that are live. A plastic disposable knife might work( a good one) if you file down the one end to be a screw driver.

Now you connect the controls back up to the monitor, then set the monitor up right, ON A Piece Of CARDBOAD, connect it to the IIgs. Pottion a mirror on the wall facing the screen. While you work on the back side. Now comes the dangerious part. You fire up the IIg then the monitor. If you have a power strip to switch on, so much the better. You can turn it all on or all off from that point. You need somewhat steady hands. When you adjust the brightness it will change the focus. So when you tweak one you tweak the other alittle also. Make notes as to what you are doing. Like which way brightens the set, which way you have to turn the focus in relation to the brighteness. Wish I did. Next time. Like I said this is dangerious, I assume no responibility to anything that can hurt or kill anyone or thing. You do not want any kids, pets or anything around when you are doing this. Do this at your own risk! Figure this is your first time it will take a few hours.

Hope this helps, there is a write up in the FAQs but no pictures. I will be replacing caps later to find out which is drifting in value to fix the problem. I plan to let it run for several hours then power down and cool one cap at a time then to power it up with in a few seconds and see if the picture improves. Then to repalce the bad part and see if it holds. All with picturs on how to do it.

BTW you may want to try the IIgs on any LCD or Plasma TV that has a composite output. There has been some success. I also plan on doing it and keep a list of which ones work with the IIgs.

Take Care

Vlad
November 16th, 2007, 06:46 AM
Being careful cannot be stressed enough in this case. The general rule of thumb voltage wise is a monochrome monitor operates at around 10,000 volts and a color monitor at around 25,000. Thats more than enough to cause a heart fibrillation or cardiac arrest. When CRT's finally give out, its usually much, much safer to try to find another one.

Druid6900
November 16th, 2007, 11:22 AM
Or find someone with a B&K (or other) CRT rejuvinator.

Rule of thumb is when working with a monitor, work with one hand in your pocket. That way, you can't take a jolt across the heart.

Another good idea is to remove rings and watches as RF will heat up the metal in them faster than you can get them off.

So, yes, monitor repair CAN be done safely, but keep all the safety procedures in mind at all times because it only takes a second to get tossed across the room.

Micom 2000
November 16th, 2007, 11:53 PM
Damn never even knew such things existed. Check out this.
http://cgi.ebay.com/B-K-MODEL-400-REJUVINATOR-FOR-CRT-RESTORING-NICE-LOOK_W0QQitemZ300171866850QQihZ020QQcategoryZ1504Q QcmdZViewItem

Right in my own back-yard, but I have too many unfinished projects as it is.

Lawrence

QUOTE=Druid6900;51787]Or find someone with a B&K (or other) CRT rejuvinator.

sirpaul484
November 17th, 2007, 11:41 AM
hmm.. That rejuvinator might be nice.. Only 2 problems with it. First, I'm pretty much strapped for cash at this moment. Secondly, I wouldn't have any idea what to do with it. Thanks a ton for all the advice!

Druid6900
November 17th, 2007, 09:42 PM
Boy, that's damn tempting, and I could no doubt get one or both of them working, but I don't get enough old monitor work in to make it worth while.

What it does, basically, is rebuild the cathode on a mono tube and the colour gun cathodes on a colour tube, burns off shorts, and, as the name implies, rejuvinates the CRT so you get a few more years life out of it. You might even get a second rejuv out of it, but, the more you do it, the less time you get out of it between jolts.