NeXT Computers

NeXT Computer, Inc. => NeXT Work Logs => Topic started by: barcher174 on December 27, 2014, 01:45:47 am

Title: MegaPixel LCD
Post by: barcher174 on December 27, 2014, 01:45:47 am
Hi All,

I did a little arts and crafts today and integrated a soundboard directly inside an LCD. Power now comes directly from the next and uses the original 19pin cable. I needed to step down 12V --> 5V for the internal monitor logic board. The soundboard easily fit in the space left over from removing the original power supply.

Everything fits and mostly functions. I'm still trying to track down an issue where there is a slight "wave" in the picture which I'm thinking is a problem with wire length for vsync and hsync.

For now it functions well enough. I had the spare monitor and sound board so this was mostly just to see if I could.

Gallery here:

https://www.dropbox.com/sc/ncz2b7bzm24on7y/AABCogevJe2HowZlFLkNa7g_a

I'll do a write up after I get the remaining issues sorted out, but wanted to put this idea out there for those considering doing a bare board conversion and have no case.

--
Brian
Title: MegaPixel LCD
Post by: pentium on December 27, 2014, 04:31:35 am
WOW! It's so clean too. Just put a lablled bezel over the connectors and it would be amazing.

Write that up and submit it to Hackaday because that there is a winner of a project. Also, try looping the sync and video wires in a ferrite bead. You could be picking up interference from the backlight inverter.
Title: MegaPixel LCD
Post by: barcher174 on December 27, 2014, 06:58:34 am
Thanks Pentium. The rolling turned out to be a ground issue. I grounded the Dsub shell to the chassis and that seems to have solved it. I didn't really take a lot of time on making the ports look pretty because it's not visible when upright.
Title: MegaPixel LCD
Post by: barcher174 on December 27, 2014, 08:56:31 am
Guide is available here:

http://www.asterontech.com/Asterontech/next_lcd.html

--
Brian
Title: MegaPixel LCD
Post by: barcher174 on December 27, 2014, 09:22:25 pm
Well looks like you were right. It made hackaday. :)

--
Brian
Title: MegaPixel LCD
Post by: pentium on August 20, 2016, 03:42:21 am
Fuelled your success I'm about to undertake the same mod and see what I can get out of the NEC Multisync LCD 1545V. According to the internet it can't handle a NeXT resolution but it seems to do 1280x1024 so it should be able to scale down a little. I got nothing to loase as the LCD was free.
It has a nice and deep back which you can fit the digital board inside the monitor with and it seems the main LCD controller can be flipped over and just barely fits out of the way. The only downside is it's a 5V monitor, so a regulator is needed to step the 12v from the NeXT machine down to a voltage the inverter and digital board is happy with. Again though, lots of space in here. I'll try and get pics tomorrow after I finish mounting the boards.
Title: MegaPixel LCD
Post by: barcher174 on August 20, 2016, 04:30:33 am
Awesome. Excited to see it.
Title: MegaPixel LCD
Post by: pentium on August 22, 2016, 01:00:22 am
As promised.

(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5642.jpg)
(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5649.jpg)
(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5657.jpg)

I discovered that the Panasonic 16v 1500uf capacitor had begun to leak when I removed it. You have to reposition it on its side or the board will not fit in the monitor.

I also realized I forgot to buy the regulator I need to power everything.
Title: MegaPixel LCD
Post by: barcher174 on August 22, 2016, 06:43:14 am
Looks super clean. Awesome!
Title: MegaPixel LCD
Post by: pentium on August 23, 2016, 01:03:30 am
Something isn't perfect yet. While the panel worked flawlessly in testing (no point modding a defective panel) now that we have most of it assembled if I power it with 5v off the bench while the LCD runs fine the backlight immediately kicks out. Either it doesn't like the extra long ribbon cable that links the LCD's digital board (there's two wires that presumably control the backlight) and the inverter, or I missed something when analyzing the old power supply and the inverter wants something other than 5v.

If all else fails though this makes the panel an excellent candidate for a full conversion from CFL backlighting to LED. (http://www.ebay.ca/itm/320mm-LED-Backlight-Strip-Kit-Update-15-15-inch-CCFL-LCD-Screen-To-LED-Monitor-/322104996256?hash=item4afef431a0:g:LAYAAOSw~oFXMuvF)

Also, if anyone is curious I am using NEC's LCD1545V 15" display. It's available in both black or white trim and while supposedly its resolution is 1024x768 I saw it running at 1280x1024 so hopefully it will be happy with the oddball resolution NeXT used that's somewhere in between.
Title: MegaPixel LCD
Post by: barcher174 on August 24, 2016, 03:56:00 am
The backlight runs on 12V. Full service manual here: http://www.manualslib.com/download/871055/Nec-Multisync-Lcd1525v.html
Title: MegaPixel LCD
Post by: Rob Blessin Black Hole on August 24, 2016, 01:01:08 pm
Very cool!
Title: MegaPixel LCD
Post by: pentium on August 28, 2016, 04:32:43 am
Quote from: "barcher174"The backlight runs on 12V. Full service manual here: http://www.manualslib.com/download/871055/Nec-Multisync-Lcd1525v.html
That is the 1525. Even in the photos the backlight inverter is of a different design.

Say Rob. Would you have any small NeXT logos? I could slap on this once I've gotten the unnecessary NEC silkscreening off.
Title: MegaPixel LCD
Post by: Rob Blessin Black Hole on August 29, 2016, 06:26:53 am
Hello Pentium: Yes, I have a small logo how about $5 and I can probably drop it in an envelope to Canada for $3  Best Regards Rob you can just paypal me and I'll send an invoice just need your paypal address . Send it to sales@blackholeinc.com
Title: MegaPixel LCD
Post by: pentium on September 01, 2016, 04:20:09 am
I will keep tabs on that once this is finished.
Title: MegaPixel LCD
Post by: pentium on September 13, 2016, 02:06:35 pm
Progress: slow.
I got dragged into helping someone buy two cars so I had to write most of the last two weeks off. When I did have the time I noticed that yes, the inverter and the A/D board do not both use 5v. The A/D uses 5v while it seems the inverter side wants 7v so that 2V difference is probably making the inverter upset. I gotta varify that is the voltage is correct but if the load is light enough I can just add a 7807 with a heatsink and we should be good.
Title: MegaPixel LCD
Post by: gtnicol on September 14, 2016, 08:02:12 pm
I've often thought of trying to find an LCD panel to replace the tube in the standard NeXT monitors. That might be another fund project.
Title: MegaPixel LCD
Post by: nextchef on September 14, 2016, 08:35:35 pm
Quote from: "gtnicol"I've often thought of trying to find an LCD panel to replace the tube in the standard NeXT monitors. That might be another fund project.


Add a intel NUC or other small pc inside and run previous or another emulator on it to create something like the original iMac.
Title: MegaPixel LCD
Post by: pentium on September 18, 2016, 06:29:02 am
Further research found that yes you were right and the inverter wants 12v and the A/D board wants 5v. Okay that is something I can more easily work with because then the inverter ties in before the regulator and the A/D after. Once all but the video signal line was soldered in the inside looks like this:

(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5893.jpg)
(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5907.jpg)
The next issue was that I had lost inverter control. When the screen went to sleep the backlight remained on and the brightness controls no longer responded. Investigation found that NEC had crossed the wiring and on the way between boards a grey wire became a brown wire and vice versa. Swapping them around made the screen entirely functional. Once I confirm the screen doesn't do anything funny running on the bench I'll tack down the video line that will cause all three color signals to be tied together and plug it into a piece of black hardware.

(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_5911.jpg)

I know that RCA jack is the microphone but does anyone know where the speaker plugs in?
Title: MegaPixel LCD
Post by: barcher174 on September 18, 2016, 07:36:39 am
The speaker hooks into the 2 pin header next to the MIC jack.
Title: MegaPixel LCD
Post by: pentium on September 18, 2016, 07:43:15 am
Should of guessed. Both traces from the header go into a nearby TDA7052 mono amplifier. Now to source a small but loud enough speaker to put inside.
Title: MegaPixel LCD
Post by: barcher174 on September 18, 2016, 09:03:44 am
I've found these to work pretty well:

https://www.amazon.com/gp/product/B00H8VXQ8M/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

They are thin and have an adhesive strip for easy mounting. I also use them in my modified sound boxes.
Title: MegaPixel LCD
Post by: pentium on October 21, 2016, 11:44:02 pm
Should of expected it. While the monitor is displaying an image because the monitor SUPPOSEDLY can't do up to 1280x1024 the image is stuck partially off the screen and all the controls are locked out so manual geometry adjustment is not possible.

(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_6215.jpg)
(http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_6216.jpg)

That being said we ARE at least getting an iamge and it's powering itself directly off a piece of black hardware. :D

So a 17" monitor is likely your minimum as it seems the majority of 15" displays max out at 1024z768 and end up doing the above when fed video.
Title: MegaPixel LCD
Post by: barcher174 on October 22, 2016, 02:37:39 am
I wonder if you could buy a new controller for the LCD? Although it could be cheaper just to get a different monitor.
Title: MegaPixel LCD
Post by: pentium on October 22, 2016, 04:41:50 am
It's going to be cheaper to get another NEC monitor. A 17" model should work however then being the weird perfectionist I am, I need to track down the right frame. Nothing with rounded edges. Flat surfaces. Square.
A Multisync 1760nx should work. It is designed to handle 1280x1024 @75hz.

(http://d2ydh70d4b5xgv.cloudfront.net/images/3/a/nec-multisync-1760nx-17-lcd-monitor-1280x1024-100ebc1f565b3b35a0b1b03a2deb84d2.jpg)

Also, I am now aware that the brightness keys on a piece of black hardware actually fiddle with the signal intensity. It was never the computer fiddling with the brightness circuit within the monitor.
Title: MegaPixel LCD
Post by: barcher174 on October 22, 2016, 05:24:15 am
Yeah, I guess I never mentioned that. The brightness controls work with mine as well.