Does any one know if it is o.k to run a soldering iron over the connector with the fine black traces on in the photograph attached(or below I am new to pic posting :D)? Back of an optipoint 410 screen after dissassembly

I have an office kitted out with Siemens optipoint handsets (410's and 500's for those interested) and they are having the missing lines issues, much like the original Gameboy does with it's LCD, which is apparently common with these handsets.

I would like to try and repair them but don't know if I can apply enough heat to do the job with out blitzing the connector. Anyone experiences with these type of connectors would be appreciated.

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    \$\begingroup\$ I would say "No" to that personally. It looks a very fragile connection, and the black tracks are quite fragile since they are just carbon. It's more likely the tracks themselves have degraded over time anyway. \$\endgroup\$
    – Majenko
    Commented Oct 13, 2014 at 15:24
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    \$\begingroup\$ I would keep the soldering iron away from the connector with the black stripes. Those are not soldered to the circuit board. The connector itself is glued to the board - heat will damage it, making your problem go from bad to worse. I wish I knew a way to fix those connections when they go bad - I recently had to junk a weather station with an LCD display because of a problem like you have. \$\endgroup\$
    – JRE
    Commented Oct 13, 2014 at 15:25
  • \$\begingroup\$ For those who have voted to hold my question. I know what the problem is with the device because when I press the connector in question the missing lines come back on. I was seeking information on the connector type and its susceptibility to heat\ heating from other users with more experience with this type of connector. This was never aimed at being a step by step diagnosis\ repair thread. \$\endgroup\$
    – Big_James
    Commented Oct 14, 2014 at 9:41

1 Answer 1


This type of connection utilizes a conductive adhesive coating the ribbon which appears to be heat activated (or at least heat activate-able). The active temperature is far below that of soldering.

On cheap, disposable examples, I've been able to remove it with a hair dryer (not a heat gun), and re-attach it by "ironing" with a large bent tip on a variable temperature soldering iron set to the lowest temperature. But I'd be very hesitant to tackle this on something expensive, at least not without a better way to control tool temperature - soldering iron temperature controls really aren't intended to work that low and do not seem to give repeatable results. If you had a way to monitor the temperature, you could try heating it to the desired point and then switching off the power.

I suspect industrially it is done with some sort of clamp that is quickly heated to a set temperature and then cooled.


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