Bright Future: Jornada 720/680 CCFL to LED upgrade

Did you use natural or cold light here?




Edited by FBustamante 2024-04-10 8:34 PM

I'm in love...

That's the warm white IMO a bit yellow not as crisp look, haven't tried natural yet. This post written in the J720 shown in photo via pcmcia ethernet card+ ethernet2wifi adapter+ WRP proxy running on home mini-pc/server... quite amazing actually!

Puppy Love my friend... cosmic infatuation sin dudo!

I will be working on a dimmer cicrcuit for this 5 volt buck converter later, as well as a full revision of the 9 volt boost converter/ rigid blue dominant spectrum LED strip alternative that I began this thread with. I am getting a handle on buck or boost converters, studying the MC6406 driver chip, etc...............again this post is from my J720/ethernet2wifi/WRP combo.

Just realized I finally passed the 1000 posts milestone!

This is amazing work @Joval!

I have 2 720's and a 728 and the CCFL in all of them is starting to dim so I will be looking at doing this replacement/upgrade now that I know it is possible

I also love your wifi work around as it is a real pain trying to get old palmtops online with newer wifi networks!

Also congrats on reaching 1000 posts!!!! Hope you get a badge for that!

Edited by fantablium 2024-04-11 8:50 AM

@Joval congrats on 1k. It's an elite club with only 22 members

I look forward to seeing the final technical diagrams for this, perhaps you'd consider posting a video showing the process - I would be happy to help produce it if you needed it.

Are you able to quantify at all the impact on battery life at all yet?

Keep up the great work, I wish I had a better handle on electrical engineering to play along in the circuit design.

Thank you... Elite Club! oh my my. Been out of town past week, but yes hoping to deliver on all this issues mentioned above. It feels good to be needed!

Here is a photo of the warm vs cool white 5 volt FlexLED options. I much prefer the cool white, image is crisp, colors more natural. Let me know what all of you think. This upgrade is so easy... although No Dimmer function... yet. But I'm aiming to get there.

Actual Screen images look better than these photos, please ignore birefringent artifacts.

Best regards...

Edited by joval 2024-04-21 2:25 AM








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cool 5vFlexLED.jpg (1368KB - 0 downloads)
warmvscool (1).jpg (329KB - 0 downloads)

I also prefer cool white.
I think warm white is too warm.

The problem will come especially when you change the original CFL, because they tend to 'red' once they wear out. So it's possible that your eyes have already got used to those colours and you notice the change strange.

Thank you very much for the photos!

I've taken several dozen photos of the ccfl and ballast power module location, removal, and Flex LED strip replacement procedure without the LED power driver installation (yet). They can be woven into a movie of sorts but need to be cropped, oriented consistently, and reduced in size before uploading here due to upload restriction. So it's in the works. What does "help produce" mean? Any help with details and presentation welcomed and much appreciated... not my forte.

Edited by joval 2024-05-05 5:46 PM

The best outcome would be to record you doing a conversion. If that isn't an option and it's just stills, then you'd have to record a voice over, or if it's better suited, we just release it in the support section as a guide and skip the complexity and time of production.

When the time comes, I can send you an upload code, so transferring is not an issue.

Hi guys, amazing what was accomplished here. May I ask a quick questions? Is the original (larger) ccfl power supply completely replaced with the buck converter? Can it be removed? I tried to ascertain from reading the posts above but it is still unclear to me.

Thanks

loonix

Yes, remove and discard the original larger 200-400? volt ccfl converter, just held in place with double sided foam tape. On a few J720's I scavenged the small brown flip connector to connect the new 5 volt buck converter input to the J720 ribbon power cable... others I just solder directly... some I added recoverable micro-fuse as well. Led strip soldered directly to buck converter output.

No dimmer circuit in most recent 5 volt buck prototype, but expect to implement this function soon, hopefully. Works fine as is but too bright in dark setting, might get better battery life with dimmer option too. I predict success in that arena.

I have abandoned the 9 volt rigid strip presently, dimmer works but in reverse, also has issues with overvoltage when 12 volt power supply plugged into J720, has numerous funky add-ons therefore complex, and color is too blue white so reds display poorly. Also costs more.(Addendum: Just located one of my 9 volt LED conversions with dimmer... very sharp crisp display, dimming is definitely nice... and gets very very bright or dim to dark... way more dynamic range than any ccfl ever, IMO. Think I'm too hasty with my earlier statement... I will do a design optimization on the circuit later and get the dimming reversed to normal).

In time I will probable make a 5 volt upgrade "kit" available to anyone interested... hey, C'Amie... can we raffle a few these off for donations? ( Eat your heart out Crait!! Sob, sob!! )

best,

Joval

Edited by joval 2024-05-08 1:35 AM

Thanks joval -

Really appreciate it.



I am definitely interested.

Thanks

loonix



Edited by loonix 2024-05-08 7:32 PM