68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.

CRT Hack

Posted by: stilgarhammer on 2010-08-21 13:38:04 Hello, I am new here and not sure this is the right section. I was given a mac classic 2 😎 , and the motherboard is damaged bad. Seems it was waterlogged at some point. there is major corrosion, so bad that the battery has fallen off. xx( I am wondering if anyone knows how I could convert a VGA 15pin video card to run the 9" CRT. I am wanting to replace the motherboard with a mini ITX board. thanks, stilgar

Posted by: Nathan on 2010-08-21 14:14:14 Any chance of a picture? I'm kinda curious how bad it is. Not sure how you would convert the VGA to the monitor's inputs. You can try reading the pages noted over here: http://www.tuaw.com/2006/02/06/mac-mini-inside-classic-mac-update/ but you'll probably need to run them through google translate or yahoo babelfish since they are in japanese. I suspect that it would consist of hacking the end of both ends of a vga cable, soldering the one set of wires to the internal part of the vga socket (could just plug it into the vga port and only hack off the other end), and soldering the other to the crt. You'd most likely need to separate the wires into the red, green, blue, horizontal sync, vertical sync, ground signals and wire them up to the appropriate places on the CRTs analog board. Anyone feel free to correct me if they know better. WARNING - High Voltages present in CRTs and CRT circuity.

Posted by: stilgarhammer on 2010-08-21 16:29:01 Hello, I am familiar with TV and high voltage. I don't have a photo of my board at the moment, I forgot to grab it when I was at my parents house (If I could find a inexpensive replacement, that would be great). the board has white stuff over much of it, there are a series of memory chips (think it the character ROM) that has turned white and has the green and rust on the pins, and the battery has fallen off completely. the chassis where the board sits has rust. I have been searching for a schematic for awhile now, any help? I could probably figure out the video if I had a one. I borrowed this photo from http://www.applefritter.com/node/21583 and did a bit of photoshoping. thanks, stilgar

Posted by: Bunsen on 2010-08-21 18:51:28 viewtopic.php?f=2&t=6619 viewtopic.php?f=7&t=12017 Use the Search, Luke 🙂

Posted by: stilgarhammer on 2010-08-23 06:35:07 Hello, Bunsen, I did try the search. I have had trouble before not finding anything because of poor keywords. May I ask what keywords you used to find those links? and the link to the MPXplayer, is vary helpful thanks, stilgar

Posted by: Bunsen on 2010-08-23 10:30:48 Well, this is a question that comes up a lot. I remembered the author of the MPXPlayer's name, so I searched for that. But you might have luck with "classic crt vga mod" or something like that

Posted by: Gorgonops on 2010-08-23 16:30:39 The one issue with the technique the builder of the "MPXplayer" used is that he leverages the VESA feature connector on the video card to supply a custom clock, and I haven't seen a video card with the VESA connector for a long, long time. (As a counterpoint, modern video cards have more flexible clock generators than "real VGA" so you *may* be able to program a current card to supply an appropriate-frequency signal with its built-in hardware.)

1