Home Forum Support Dim display on KIT1

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  • #6777
    fix4all
    Participant

    Just received the KIT1 and connected on-line. All works as far as I can tell except for the hardly readable display. Noticed the PCB on the upper end/edge is bowed. If I place pressure on the upper corners of the display it seems to correct itself with perfect dark contrast. I thought that fixed the issue, yet about an hour later the display dimmed again. It appears to be an internal contact issue between the display and underlying PCB. Checked the mainboard PCB header pins, solder joints, etc and nothing stood-out.

    Please see attached pic’s..

    Greg

    #6781
    Wolferl
    Moderator

    Hi Greg,

    It seems the zebra strips (conducting rubber) that connect the display elements to the display’s PCB do not make proper contact due to the bending of the PCB.
    You can try to even out the PCB bending by heating up the connector solder joints. You have nothing to loose there.
    If all fails, there are lots of Nokia 5110 display sellers out there, just get a new display module…they are cheap too.

    Cheers,
    Wolferl

    #6794
    fix4all
    Participant

    Hi,

    So, ordered a new 5110 display for almost nothing in cost. The display PCB was substantially thicker than the stock display PCB that came with the KIT1. The display also appeared to be higher quality and slightly bigger and incorporated gold plated spring contacts unlike the conducting rubber strip of the stock one. The newly installed display would have have been perfect except that it slightly interfered with the 3D printed case. A bit of filing would have remedied that, yet decided to fix the original display to use for now.

    The problem with the stock display is the thinness of the PCB and the pressure exerted upon it from the conducting strip causing the PCB to flex, thus compromising the contact between them. I separated the display, straightened the PCB, epoxied a solid thin bar of steel on the underside of the PCB, re-soldered the header pins and remounted the display. The PCB no longer bows as it once did. Oddly, the display contrast is very high now where there is a faint dark background. Is there some control for the contrast or a resistor value that can be altered?

    It would be nice if the KIT1’s would incorporate a thicker display PCB with the spring contacts or soldered ribbon cable. Eventually, will get around to installing the the new Display/PCB unit when I have time to mod the case.

    Here is the link to the displays purchased on eBay. I purchased an extra discreet white display without the PCB and that was similar to the stock with rubber strip. The complete unit with white LED’s has a slightly larger display, thicker PCB and spring contacts. The blue LED complete unit has a soldered ribbon cable connecting the PCB to the display! Unfortunately, only a single header pin strip is provided per complete unit.
    Nokia 5110 on eBay

    #6848
    Radu
    Keymaster

    Greg, did you do any progress on this?

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