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any tips on unsoldering the tiny jumpers

Posted: Mon May 11, 2015 8:32 pm
by ghost2501
I have a new display I want to turn to i2c tll communication. The jumpers are so small and when I tried to heat them up it didn't seem to work. do you think it would be ok to use side cutters and cut them off adn then unsolder the remains. They are so small.

Re: any tips on unsoldering the tiny jumpers

Posted: Tue May 12, 2015 9:10 am
by Clark
Hi Ghost,

I understand you'd like to move your protocol select jumpers from RS232 to I2C communication. Are you still working with your LK162-12, or is this another display?

First, I would recommend using caution, any damage caused during modification may not be covered under warranty. That said, I would say side cutters should be used as a last resort.

Using a soldering iron, I would recommend using flux and a temperature of 720F to 750F. If you are working with your LK162-12 Rev2.2 unit, you will have solder connections only. If that is the case, you might try using a wooden toothpick to separate the solder blobs once they heat up.

Cheers,
Troy

Re: any tips on unsoldering the tiny jumpers

Posted: Wed May 13, 2015 11:19 pm
by ghost2501
I have 2 brand new lk202-25-v and would ideally like to have one as i2c and one as TTL serial. I am just nervous about using that much heat on jumpers so small I will have trouble grabbing them. I just cant let all these displays sit here anymore if I ruin them then oh well. 10 matrix orbital displays here and not one is able to be used with my arduino. On the one I managed to unsolder all the tabs I spent 2 months trying to get it working and the labels were backwards in the manual so I imagine I bricked it alone one of those tries So I am just never getting anywhere until i remove these rs232 jumpers.

Re: any tips on unsoldering the tiny jumpers

Posted: Thu May 14, 2015 8:48 am
by Clark
Hi Ghost,

With your brand new LK202-25-V units, you'll have 3 x 0603, 0 ohm resistors to remove from the RS232 protocol block, and 2 x 0 ohm resistors or solder connections to make on the I2C block. Two soldering irons would definitely help here, but one will do the trick. The resistors will typically stick to the iron once they are loose, so you shouldn't have to worry about grabbing them. Please be sure to use a little flux, and a temperature setting with which you feel comfortable and you should have no problems.

With regard to your LK162-12, both the Rx and Tx ports of the controller should be 5V tolerant, so swapping them while in TTL mode would not brick the unit. There may be some life in that old display yet.

Cheers,
Troy

Re: any tips on unsoldering the tiny jumpers

Posted: Tue Nov 17, 2015 1:43 am
by diyhouse
I see this has been a long standing post,... but for ref purposes,.. some good de-solder braid works a treat!!

It allows one to pull off the excess solder and the zero ohm resistors should just fall off,.. if they don't, using a wooden tooth pick seems to be a good idea.

..But under no circumstances use wire cutter to break the link,.. as this will almost certainly pull the pads of the board and cause irreversible damage, and although not necessarily bad,.. for the final application, this level of board "modification" can never be good for the final app..

Re: any tips on unsoldering the tiny jumpers

Posted: Tue Jul 19, 2016 4:30 am
by delshay
If you are unable to do this yourself, take device & print-out manual to an expert. Do not risk your hardware.