LCD design, is this good enough?

[frodonl]

While I don't need it yet - my pc-1 only has a VERY small, nearly invisible, bit of leakage in the top-left corner - I sure plan to order one of these displays once they become available. After all, one never knows what might happen in the future.

Great job!

[robertbaruch]

Yay! The LCDs have come in and are now available for purchase.

This is the end to a very successful project and learning opportunity. I've reached break-even already, and now I'm looking for the next LCD problem child. Suggestions welcome!

--Rob

[TERRA Operative]

Maybe some of the older HP bench multimeters.
They tend to fade and one LCD design could possibly do multiple models.

[robertbaruch]

I'm actually surprised, I didn't know there were that many PC-1/PC-1211 enthusiasts out there. Of the original stock of 200 LCDs, I've sold half of them already. Possibly I'm in the long tail now, but I honestly thought I'd sell maybe 20 or so.

[james_s]

I wonder if there is a company that can do custom VFDs in similar low volumes? I know there are various instruments out there with worn out displays. I remember some time back someone did a hand made LED display replacement for a Fluke 45. Actually an LCD version of that might look quite good too.

[JCCyC]

I'll have two!

[demod]

Thanks, just ordered one!

[demod]

Finaly had a chance to look at my PC-1.  Definitely has an LCD problem.  Before the new LCD when I power up it I get a display like it is trying to enable all pixels.   I don't think this is a LCD problem.  Has anyone seen this before?  I can't see any obvious issues.

After a reset it changes slightly, and very occasionally it will have a constant beep tone, until reset again.  (see attached pics)

Not sure I want to change the LCD when it is like this, might be a waste of time.

(is there somewhere people are discussing repairs to these units?)

[aldweb]

Hello,

So, I could replace one LCD to one my devices, with success, wonderful. I left a positive review on robertbaruch's Tindie page, he so much deserved it for his work!

When finalizing a second device LCD replacement, still with success (LCD working with full contrast), I had an issue in the final step when you want to remove the wiper on the contrast pot to get the right contrast, because the pot just broke apart (white plastic part to old?)

Reading back this thread, robertbaruch wrote back on April 9th: "A qualified success! Qualified because (a) I still need to reproducibly replace an LCD without several tries, and (b) you have to replace the contrast adjustment with a 240k resistor."

So, would it be enough to unsolder the plot, replace it with a 240 KOhm resistor?
What resistor would you recommend? Would this one ( https://www.conrad.com/p/metal-film-resistor-240-k-axial-lead-0207-06-w-1-1-pcs-421022 ) work for instance?
If you had any picture of the final result, this would help me, thanks.

Thank you for your help,
aldweb

[aldweb]

Hello,

I will answer myself, in case somebody else would be interested in doing the same thing as me when you find yourself with a defective contrast pot or fail to remove the wiper as explained in robertbaruch's instructions.

So, I replaced the contrast pot with a 240 KOhm resistor.

I removed the contrast pot and cleaned the area from any remaining soldering --> see first picture
I then soldered the standard 240 KOhm resistor --> see second picture

After that, the replacement screen worked like a charm 

Cheers,
aldweb

[tabajaralabs]

Any updates on the LCDs? I have a pair of PC1211s waiting for them =)

[Keatah]

Is it possible to use the yellow-tinted polaraizer with these replacement LCDs?