• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Another crazy portable hack of mine

techknight

Well-known member
Its not. does the same thing if I leave the EL sheet turned off. Although it is not out of the realm of possibilities, considering the EL sheet is a big capacitor essentially, and its not grounded to the chassis (inverter is seperate) 

Ill just leave it alone, its not like its going to be on 24/7. 

I do have another spare LCD that I might go ahead and destroy, Maybe. 

The LCD I used was from a parts machine that was busted up in shipping, shredded ribbon cable, (that I had to fix), and a bad motherboard as well. I bought this portable last week just for hacking. I was going to convert it into a modern machine considering I already have a 5120 and 5126 for my collection. This third one was specifically for hacking. 

But since this one has cracks that I had to glue all back into place, I decided to not proceed with the PC conversion. Instead, I decided to use this as my hack/mod/hotrod machine. So the first thing I started with was the backlight mod. Of course, it was missing the battery when I got it, and they nearly destroyed the machine by removing the HDD. they basically shredded the floppy, and LCD ribbons. somehow. I had to rebuild the LCD ribbon, and replace the floppy ribbon. 

Regardless, i had no idea if the LCD was even good to start with. But I have a whole upper display head assembly that I got from Uniserver a couple years back for testing/parts. It seems to work perfectly fine. 

I could mod it like i mentioned, and use this first LCD attempt as a test LCD for benching logic boards and leave it at that. 

 
Last edited by a moderator:

unity

Well-known member
Maybe if you try another, bake it for a while first to get overall heat up. Then with a helper, that pulls evenly, use a heat gun again. Heck, with the right oven temp one may not even need the heat gun. Just a thought.

 

techknight

Well-known member
Well you cant get it too hot. Because the reflective material film is sitting on top of the polarizing film. Trick is to remove the reflective material without damaging the polarizer. 

 

techknight

Well-known member
It was the LCD panel for sure. 

I grabbed my Test screen which i know for a FACT is good. Performed the same proceedure peeling the film off, and cleaning the adheasive. 

Works fine. no tunneling. 

 

aplmak

Well-known member
Techknight... can those two caps on the back of the non-backlit be replaced with tantalums??? There are other tantalums on it.. not sure why they used electrolytic... I would assume there has to be a reason?? No?? I know I've asked you this question before but since you were pulling apart a 5120 LCD I figured you'd see those little guys on it and know what I mean...

 

aplmak

Well-known member
And I mean the two on the back of the LCD display of the non-backlit... a 10uf 16v and 220UF 10V

 

uniserver

Well-known member
i guess youtube videos are not auto inserted from a link.

 
Last edited by a moderator:

techknight

Well-known member
Lots of factors. Price, Availability of that value, etc.. can factor into the choice between ceramic, electrolytic, and tantalum. 

Also, all 3 types of capacitors have their own parasitic effects as well. For example, the Ceramic capacitors will vary their capacitance based on the voltage applied across the dielectric. This effect may be undesirable for that part of the circuit. I do know this wrecks havok in vertical deflection circuits, it distorts the waveform. 

 
Last edited by a moderator:

olePigeon

Well-known member
Oooooooo!  That's cooler than I imagined. :D

If you can put together a bit of hardware to make it plug-and-play, this would make an awesome kit to sell.

 

olePigeon

Well-known member
I have a question... can the LCD form a Macintosh Portable be used with a CRT Macintosh?  If so, can you make a backlit LCD 128k?

 

olePigeon

Well-known member
Ooo.  Someone with a spare Portable and a Compact care to examine the innards?  A cool lit LCD 128k or 512k would be pretty darn cool. :D

 

techknight

Well-known member
I have a 512x256 Planar EL display i was going to interface, but the lack of some vertical resolution sorta killed the project before I got started. There has to be pixel/timing room for the front porch and back porch periods of the sync pulse. (blanking interval). 

 

uniserver

Well-known member
awesome mike, have you done any battery life tests?   do you think this will consume much less then a 5126 back light setup?

 

techknight

Well-known member
I dont know, and no I havent. I have to design a new inverter that can run between 6 to 7VDC. The one I have is for 12V only. 

 

olePigeon

Well-known member
Man that stuff is cool.  I just Lycosed it on the tubes, and found out that you can almost cut it like vinyl, then run jumper wires between the little pieces.  Make illuminated signs. :)

Now I want to make a tiny Apple logo where the badge is normally, then make it glow.  :O

 
Top