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Keyboard screen...cable

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New Member
Hi all, newbie:angelic:

I'm repairing a keyboard at the minute, it's a Roland GW7 if anyone's interested in instruments.
It's in two parts with the back light and the screen which is connected via a very thin cable as shown in the photo's.
I found that if I run my finger over this cable the screen will come on. So I heated it up a bit which actually fixed it!!
problem being that it only lasted about a hour before coming less tight and going off again.
(when I say going off I mean the actual text the back light is fine)

I've never seen this type of cable/film before, does this have some name?

What's basically wrong is that the glue holding the cable to the back of the board has come loose, hence me heating it to try and make it re-stick.
Does anyone have any idea's on how to fix this? can it be re-glued or can you buy this stuff and cut it to size?


Just to add, that front bit comes away from the back but is connected by the flex cable
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Well-Known Member
When this happened in certain cars, we used to use a firm piece of rubber or similar to apply pressure to the ribbon cable and make sure that when the screen is in it pushed against the rubber. A bit of a botch but cheaper than buying a new one !


Active Member
This is an iteration of ACF (Anisotropic Conductive Film) technology where an automated heat bonding is used for electrical connections. A good number of smaller products in consumer and test instruments industry have used it. While cost effective, the glue has a life cycle.
Since it is usually an automated process, once separated, it is very hard to put back together with good results. Tons of you tubes out there claiming various ways for repair.
In the past , i have had some success using a controlled heated iron. The biggest issue is reforming the existing glue or lack of it.
Here is a good demonstration from PCB to display among various applications;https://www.youtube.com/watch?v=biHFJFHpqdM

Les Jones

Well-Known Member
Most Helpful Member
Hi vtech,
It's a noce video of the process. It's a pity it does not give details of the temperature and pressure required. I had a problem with a Honeywell CM901 programable central heating thermostat display. The information I found on the web said the temperature needed to be above 130 Deg. C (It did not give an upper temperature.) and a pressure of 30 Kg per square cm for about 3 seconds. Hear is a link to my very crude device for doing the repair,

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