Thread
Another crazy portable hack of mine
Yup, and at a much lower current than EL.
EL runs at a low voltage, and higher current.
The reason why EL inverters are larger than CCFL, is the frequency. EL frequencies are anywhere from 400hz to 800hz or so. while CCFL runs well above 18khz. maybe even 20 to 30khz.
Easiest EL inverter is taking an old wall transformer, you know, the old 120v to 12v or 9v, and use it in reverse with a 555 timer and switching transistor.
EL runs at a low voltage, and higher current.
The reason why EL inverters are larger than CCFL, is the frequency. EL frequencies are anywhere from 400hz to 800hz or so. while CCFL runs well above 18khz. maybe even 20 to 30khz.
Easiest EL inverter is taking an old wall transformer, you know, the old 120v to 12v or 9v, and use it in reverse with a 555 timer and switching transistor.
Is it possible to make an EL inverter small enough to fit inside the Portable?
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Probably. But we gotta see if it can deliver the current to the EL without overheating
Wow. I like this!
Small pie fan?
Well, The results are bittersweet.
Here is the result after assembly: Looks nice! BUT... and I mean a big BUT...
If you look at the LCD, After its been on for at least 15 minutes, it begins to "develop" the film pull lines as if it were tunnel vision:
These displays are sensitive to this I suppose. I didnt use much heat when pulling the transflective film off, But I did pull hard. I am wondering if I damaged the LCD from doing this, it looks like I did.
Was worth a shot I guess. Next time, I just have to use more heat and pull slowly. be VERY careful. I was pulling on the sheet, HARD.. the tunnel vision "creases" appear to be at the points where I rested after pulling.
Oh well....Its not really affecting it that bad.
there is also a black line that develops on both sides of the LCD as well around the same time. This could have happened before I took the LCD apart ,as I have no idea if this LCD was good or not. I got it for parts, and started with it. This could have been a problem before I even started. I dont know.
Its not affected whether the EL is on or not, it still shows up after awhile. Just like tunnel vision.
Here is the result after assembly: Looks nice! BUT... and I mean a big BUT...
If you look at the LCD, After its been on for at least 15 minutes, it begins to "develop" the film pull lines as if it were tunnel vision:
These displays are sensitive to this I suppose. I didnt use much heat when pulling the transflective film off, But I did pull hard. I am wondering if I damaged the LCD from doing this, it looks like I did.
Was worth a shot I guess. Next time, I just have to use more heat and pull slowly. be VERY careful. I was pulling on the sheet, HARD.. the tunnel vision "creases" appear to be at the points where I rested after pulling.
Oh well....Its not really affecting it that bad.
there is also a black line that develops on both sides of the LCD as well around the same time. This could have happened before I took the LCD apart ,as I have no idea if this LCD was good or not. I got it for parts, and started with it. This could have been a problem before I even started. I dont know.
Its not affected whether the EL is on or not, it still shows up after awhile. Just like tunnel vision.
Not sure what you mean by black lines, but my 170 has some odd black lines/edges. Looks like it was just part of the production process - primitive back then.
As for the creases, you maybe can try massaging to see if they go away. Also did you clean the display back with alcohol or something? My other though may be that its residue.
As for the creases, you maybe can try massaging to see if they go away. Also did you clean the display back with alcohol or something? My other though may be that its residue.
Nope, screen is clean.
I think the LCD is actually bad. Take a look at this:
That was after about 45 minutes or so? of being on.
Just powered it down, and it seems to have the creases and if you look very carefully, the About Finder "burned in" to the screen.. With the memory etc still present. The LCD panel itself seems to be holding a residual charge which isnt normal.
Thats definitely a bad LCD. Since this is an active matrix LCD, there are little PolySilicon transistors on each pixel. There should also be a ground plane in the panel to dissipate the charge when its not in use, etc, but its not functioning for some reason.
I think the LCD is actually bad. Take a look at this:
That was after about 45 minutes or so? of being on.
Just powered it down, and it seems to have the creases and if you look very carefully, the About Finder "burned in" to the screen.. With the memory etc still present. The LCD panel itself seems to be holding a residual charge which isnt normal.
Thats definitely a bad LCD. Since this is an active matrix LCD, there are little PolySilicon transistors on each pixel. There should also be a ground plane in the panel to dissipate the charge when its not in use, etc, but its not functioning for some reason.
I am sure you do not want to take it apart again, but I wonder if the EL sheet is causing the ghosting issue?
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.
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.
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.
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.
All I can say is Mike is a genius!!! He is the man!!!!
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.
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.
Good to hear!
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...
And I mean the two on the back of the LCD display of the non-backlit... a 10uf 16v and 220UF 10V
i am beginning to see that apple used elecrolytics because they are much more tolerant to things like voltage spikes and reverse bias. because even apple knew then the possable dangers of tantalum caps.
https://youtu.be/u1Gsf9Lzkyg
https://youtu.be/u1Gsf9Lzkyg
https://youtu.be/u1Gsf9Lzkyg
https://youtu.be/u1Gsf9Lzkyg
i guess youtube videos are not auto inserted from a link.
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.
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.
Oooooooo! That's cooler than I imagined. 
If you can put together a bit of hardware to make it plug-and-play, this would make an awesome kit to sell.
If you can put together a bit of hardware to make it plug-and-play, this would make an awesome kit to sell.
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?
Maybe, but I do know the LCD is proprietary.
Very good work!
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.
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).
awesome mike, have you done any battery life tests? do you think this will consume much less then a 5126 back light setup?
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.
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
Now I want to make a tiny Apple logo where the badge is normally, then make it glow. :O
This makes me regret not getting that portable at a computer meetup for $15 in 2012. 