use whites DFX SCREEN on a XLT DIY REPAIR

[juit]

found this on the web, maybe it could help some one that is on the same boat as me (Im just quoting the post):


The orginal display is a EL p98-1 display






I changed mine to LCD 128x64, draws a lot less current on the back light.







You will need a 20 pin header soldered on and change out Resistor R-108 on the board and then solder two wires for the LED back light voltage. The only disavantage is the back light control will not work on the key pad anymore going to LED. I put a resistor in line to dim the back light down and it stays on all the time but does not pull the battery down like the EL backlight.





R108 - Put a 6.8k resistor in parallel with old resistor for viewing angle to work correct.







part name: Port 12864 Module ST7920 Yellow Green Backlight LCD Display Diy Kit 128x64 Dot n




Jim Walker from facebook is the guy who shared this
he is the man!

[juit]

jim walker is the man!

[Polymer]

Thank You for posting this!

It may come in handy one day for myself or others with an XLT.

Cheers

[arizonan]

Hi there! I wonder if I can jump in. I have the XLT display issue as well, and I also have an ST7920 12864 module from an Arduino project I was planning to start.
I would like to repurpose it to fix the XLT but, I cannot see the R108 in the silkscreen, as refernced above.

I am including a picture here in the hope one of you can help me. https://imgur.com/a/bAC92qx


Any hints?

[nickel_n]

could be that the R108 resistor is part of the XLT pcb

[kt315]

could be that the R108 resistor is part of the XLT pcb

there is second pcb, 'invisible' for somebody. it stands inside LCD box.

[arizonan]

there is second pcb, 'invisible' for somebody. it stands inside LCD box.

Oh. I will get brave and see if I can detach the LCD from the main module.
I will post here the results.

[PSS]

Hello, this does not work or I had received a bad 12864 LCD display. What you are looking for R108 it is on the board labeled 505-0199-B that the display plugs into. It made no difference for me since the display did not show anything but two shades of static in two rectangles with or without the additional 6.8k resistor in parallel. Let me know how yours gose. Perhaps my display was bad.

I forgot to mention that it also is not a direct replacement as it is several MM thicker. But could still be retrofitted if it would work.

[sinclairuser]

Hello, this does not work or I had received a bad 12864 LCD display. What you are looking for R108 it is on the board labeled 505-0199-B that the display plugs into. It made no difference for me since the display did not show anything but two shades of static in two rectangles with or without the additional 6.8k resistor in parallel. Let me know how yours gose. Perhaps my display was bad.

I forgot to mention that it also is not a direct replacement as it is several MM thicker. But could still be retrofitted if it would work.

i think you had a dodgy screen, the replacement of the whites screen with a generic one is a known fix at this point and has been done, however only with the 12864 Module ST7920 Yellow Green Backlight LCD Display Diy Kit 128x64.
the fix only seems to work with this exact module, i dont know why but anyone who uses these modules will tell you they are not created equal, lots just seem to be DOA its a lottery.

[PSS]

Perhaps, but I have seen no actual 12864 LCD working just a thread that gets reposted like here that says it does with no one else backing the claim. I have attempted it with two different modern screens and both were a no go. The 2019 ST7920 LCD doesn't even fit into the DFX screen housing without grinding the plastic back that holds the screens since it is thicker than the older original model screen. Since they do not work no sense in retrofitting it first if anyone is reading this and attempting it. The old ones that I think you are remembering fit as stock but are a slightly different model.

It would be nice if someone else could actually provide the proof that this works other than just someone saying it does without actually doing it. The one picture that gets passed around is with a blue screen and I believe a different style. the green screens are now also made to same specifications just backlit green and also do not fit. It would be great to get these working since they can be had for as low as $10 US in blue. but I still can only use the older style and they are about $100 without buying in quantity. If this actually worked there would be videos etcetera and chatter about it on forums.

[Ficricchio]

I also have to change the display of my XLT spectrum so I'm going with this 3d (I don't know if I did it right, otherwise excuse me).
Does anyone have the datasheet for the phico 98-1 display? Thanks.
Many people say they replaced the display, but no one says which display they used (and how they did the replacement). By now I have tried them all, many displays, ST7920, drivers KS0107, KS0108. replaced, added in series and in parallel the "famous" R108
resistor, but without results, unfortunately.
Thanks to anyone who can give me information on this.