Using J720 parts on J728 or viceversa

I bought an used Jonada 720 a month ago 06-DEC-2008 (US$125). I think it was a very good purchase given the J720 was in excelent condition (just HP, Handheld PC and Windows Powered white logos quite erased in the cover but nothing else). It didn't come with the cradle and it had the stylus missing too. But it came with the manual, AC charger, and serial cable.

I've been testing the equipment and so far I have realized that:

1. External alarm led is not working (but the button does work to stop the alarm). Not a big deal but nice if it just worked as supossed to.

2. IRDA port doesn't work. This is a must for me because I wanted to use a cell phone with camera to transfer photos to the jornada (given that the jornada doesn't have a built in camera).

Everything else was going ok, I haven't tested the PC card slot since I don't have any card to insert there yet....I'm very happy with this handhelb PC but.....

....Today my jornada just accidentaly fall from 5 ft height and one of the plastic clips under the battery compartment just broke and the hinge get loose in the right side . I've tried to insert the clip in place but it's very difficult.
The jornada is still working but I'm affraid of things getting worse. I just figured that I must disassembly the J720 in order to attach the hinge again.

Some help here please.

Also, the store where I purchased the product had a broken Jornada 728, The salesman told me that only the screen
doesn't work (the entire equipment looks ok, it just doesn't turn on). It was not for sale but I think it could be bought.

My questions are:

1. Would it be ok to buy the Jornada 728, I think it will not cost me more than US$45 and just the second battery will pay back big part of the money (US$30 as sold on amazon)

2. Can I take off the screen from the J720 and use it on the J728?

3. Can I take parts from the J728 and repair the J720, maybe taking it to any computer service center?

4. Can I just simply exchange external cases (housing) (i.e. replacing the one with the broken clip)

5. Can I take the full J728 electronics with the J720 screen and assemble all in the J720 housing (so I will have a 720 with 728 capabilities- given the advantage of the J720 blue plastic finish vs J728 scratchable gray painted finish).

And if possible, how difficult is it?

thanks

You can use the 720 screen with the 728, and changing screens is not too difficult. (Just be careful handling the orange screen ribbon cable so you don't damage the connection - I'd bet that that cable is the fault in the 728 screen.) Nearly all the parts are interchangeable between the 720 and the 728. (I even used the screen cable from the 680 to replace the one in my first 728 when that 728's display failed similarly to the one at the store you mention. That 728 is once again working fine.)

I think that every disconnectable part is interchangable actually, isn't it? Including the ram/rom.

I wasn't sure about the RAM, because of the difference in data capacity.

Yes. Everything is interchangeable between J720 and J728. Of course, if you change 64MB RAM/32MB ROM to 32MB RAM/32MB ROM, you actually downgrade J728 to J720. You upgrade J720 to J728 the other way.

Edited by CAuser 2009-01-07 8:57 PM

If you like the 720 case better than the 728, you can put the 728 parts in the 720 shell. Somewhere on this site is a video on disassembly...all you need is a #6 torx screwdriver and strong fingernails. I also use a plastic pry-tool built for disassembling a Dell laptop to get Jornada parts loose without marring the plastics. Also, if you need additional help, the ebay seller Gumboya has static pics of the disassembly process. Also-also, if you have a backup on the 720 and want to use it with the 728 memory module, it will not restore....you need to reload programs from scratch...so my experience has been.

for jornadas, the RAM is on the ROM board. if you upgrade the ROM the RAM comes with it, no other way to do it. what data capacity do you mean?

to Hal: yeah I could not restore 720 backup to 728 either. well it restored (IIRC, who knows, it was in march of 2005 ) but some things didn't work like the wlan driver

Edited by cmonex 2009-01-08 1:29 AM

That's what I wasn't sure about - though I've taken apart a few Jornadas, I didn't recall seeing the RAM/ROM module layout.

Thanks Hal. I just downloaded and watched the video (I even bought a torx tool set)....but It looked a bit too complex for me to reach the screen (It is required to take off almost every other part that are already working fine so there's a risk on doing that).



What you said is exactly what I'm afraid of: To get something connected wrong or to damage some connections during the disassembly / assembly process. And there is a warning at the end of the video telling us that a wrong connection of the screen can cause some weird lines on the screen. But ...You can only test that when every part gets into place again to be able to turn on the jornada.

Anyway....after watching the video...I got so frustrated that I just take a shot forcing the loose hinge into place....and....bad news...another plastic clip broken!...Now the hinge is really loose on the right side of the screen. Then I had to use some transparent glue to get the thing temporarily fixed. Part of the glue is inside the battery compartment out of sight....but I had to apply about 5 mm line of glue (with 1 mm thickness) in the inner right corner of the hinge that can be seen when jornada is opened (Now I'm looking for some nice sticker to cover that. Something like "Windows Powered" or "Handheld PC 2000" would be cool but ...where to get one?.)

Right now the "disassembling and changing shells idea" is the only way to go.




hmmm...this sounds a little easier....As shown in the video I just have to take off the keyboard to reach the ROM/RAM module.

I think changing ROM/RAM module could be the start point. This is a second reason to buy the broken J728 (along with the extra 14 hour life battery).