Damaged Lcd Display Korg Electribe SX-1

[yekuku]

hi guys, i d appreciate some qualified help in this one.
just got my second-hand Korg Electribe SX-1 from ebay and i noticed that the Lcd Display does not work properly.
when previewing names/options on the display the 6th letter is always missing.
it seems that the pixels of the 6th column refuse to turn black in order to show the appropriate letter. plz check the attached picture.
does anybody have exprerience with fixing small lcd displays?
is there sth i can do in order to fix it?
i am not a professional technician but i have experience with audio related repairs. Unfortunatelly i dont know anything about LCD displays.
thanks

 

[Albertb]

Like you I'm no expert at LCD display electronics, but if the entire letter is missing this could suggest something wrong with a commoned path, (assuming that the method of illuminating each pixel type block in the letter is to control one terminal and common the second with all of the other pixels in that letter.)

If that is the case it may very well be a manageable fix. Is there any evidence of anything contaminating the board or components. From what I understand LCDs are more electrostatic than anything else and any tiny current drain across tracks could affect their action.

 

[yekuku]

hi albertb and thank u very much for your input.
i took a very close look at the unit and realised that in fact it is not actually a letter missing from the 7th pixel block but the 2 last pixel from the 6th column and 4 first pixel from 7th column. plz check pic.
i thought that there could be a problem with the contact that is responsible for the 7th pixels block, but it seems that i am wrong.
i ll open up the unit ,i ll take some pics and i ll let u know.
thanx for reading guyz

 

[yekuku]

well, i opened up the unit and for my suprise the LCD display is broken plz check the pics
there is a small crack at the bottom right corner.
But it seems that no vital parts have been damaged.
i got this unit 2nd hand and i dont know if the display problem is due to the crack or due to sth else.
i checked the lcd display contacts and they seem to work ok .
any ideas?
if the broken display is the problem does anybody knows how can i replace it ?
thanx

 

[pinkmouse]

I would imagine it's a Korg custom part, so you would have to source a replacement from them. As for repair, I suspect if you have checked for the obvious dry solder joints and suchlike, there is nothing else you can do. Contact Korg tech support.

 

[yekuku]

thanx for the input pinkmouse,
yes i ve checked for dry joints and suchlike but they seem to work ok.
i d like to have some ideas about this from experienced users before i order the replacement part.
just to make sure that the crack causes the problem.
in this pic it is shown clearly that the crack does not affect vital components. ( at least i think so...)
any ideas about this would be very much appreciated.
thanx for reading guyz

 

[pinkmouse]

Impossible to say. The crack may be related, it may not. Looking at the number of pins, (unless there are more hidden underneath), there are not enough for a matrixed display, so the display probably has an on board processor to translate serial or parallel data into pixels. If this has gone wrong, there is nothing you can do about it. Do you have a scope?

 

[yekuku]

Do you have a scope?

Unfortunatelly not.
i dont have a clue about LCD displays, i am just an audio technician
Also i cant see any pins and how the display is connected to the board.
there are 2 rubber (?) rows ( the pink ones, up and down ) that hold the display and probably are responsible for the communication to the board.
here is a pic of the back side of the display.
thanx for your help.

 

[imix500]

That type of display has no on-board drivers/controllers, everything is external. The thin black stripe on the top and bottom- that is the conductive strip that transfers electrical signals from the pcb to the lcd. It's a bit of black magic going on there as the traces on the lcd glass can't be seen easily. The crack in the bottom corner is certainly breaking traces going into the lcd. Also, from the picture the conductive strip looks a little bent down from the breakage, this is probably enough to throw it out of allignment. The lcd is probably not repairable, but certainly replacable.

 

[pinkmouse]

That makes sense. Well spotted.

 

[yekuku]

The thin black stripe on the top and bottom- that is the conductive strip that transfers electrical signals from the pcb to the lcd. It's a bit of black magic going on there as the traces on the lcd glass can't be seen easily. The crack in the bottom corner is certainly breaking traces going into the lcd.

thanx for sharing your knowledge
this info was really useful in order to understand how the components of the display work.
i guess then that it is not repairable
Thank u all very much for your help, i really appreciate it

 

[pinkmouse]

If you can't get a replacement, you might be able to fix it using a powerful microscope and electroconductive paint.

 

[yekuku]

can u plz, recommend me a quality electroconductive paint/glue?
i ll probably order a replacement LCD, but i d like to give it a try first.
thanx