Mindboards

Yesterday I used a soldering iron on 4 NXTs. 3 of them had non-functional screens. After the soldering all three of those started working again. How long they will last will be interesting to see. The 4th NXT had a very dim screen but it was mostly functional. It has had button issues in the past that I have fixed via taking it apart and cleaning the circuit board with some rubbing alcohol. It is my oldest NXT. After trying the soldering iron repair on it the screen now shows nothing.

I have a pre-production EV3 that I broke by taking it apart and (apparently) damaging the ribbon cable to the LCD. The brick still works but nothing shows on the screen. With the standard EV3 firmware it will not be possible to use a remote screen viewing utility like my NXT Screen tool. I am looking into what I can do to remedy that situation.

John Hansen

Thanks, I'll maybe have another shot at repairing mine.

Used a conical point on the iron, maybe didn't get enough heat on last time - was afraid of frying the components.

Bought a brick off ebay (complete with power pack for just under £70 so at least I have a spare again and can risk the repair.

Had a complete set but gave it away to my great grandson just before I discovered my 'spare' brick was malfunctioning.

It's true what they say, no good deed goes unpunished!

I had less luck with that, on one NXT whose screen flickered. After trying all the "tricks", the situation is more or less the same. Fortunately with NXTScreen utility it's not completely useless...

I've done the resoldering capacitors trick, and it's worked, marginally. Sometimes the screens lasted for months, sometimes just a few minutes. I've done it several times on two NXTs. I finally called LEGO about it and they replaced them, so you could try doing that.

I did ask LEGO USA, who referred me to LEGO Europe.

No LEGO sales record, no repair, and I bought all my sets second hand.


"The NXT products come with 2 year warranty.

If I can trace that you have placed the order with us in that time then we can arrange for a replacement to be sent out to you free of charge.

Please provide me with approximate date of our order, full address for invoice and delivery and order number (if you can find it).

Otherwise, I am afraid we do not offer a repair service."

These problems all have a similar cause. The contacts for the four push buttons are on the same board as the connector to the screen and some capacitors. Pressing a button stresses the board and, in the end, cracks the solder of the capacitors or connector. It would be interesting to know if Lego improved on this design issue of the NXT. Is the print for the push buttons also used for other purposes? If so, I have the LEDs in mind, then also these might prove vulnerable in years to come.

The NXTs in the 1.0 had a separate daughter board with the buttons and LCD on it. I haven't heard of a NXT from a 2.0 set having its screen die, but I don't remember what they did to fix the problem.

Hadn't thought that pushing the buttons could cause this problem.

I think I will try to use touch sensors to make selections in the future.

There was a revision that moved the contents of the daughter board to the main board. Also, the buttons which were about 1/2 inch tall, were extended to two or three times as big, so they could reach to the main board. I don't know the exact dimensions of the buttons, so don't worry about correcting me.

I think the problem was the type of solder that was used. So I suspect if you could remove and replace the solder, things would work better. I have many that have bad displays, and many that I've fixed.

Steve

Well. I finally tried to repair the NXT screen by re-soldering the caps.

Got some lines on the screen but that was all, then I noticed it kept changing as the screen was moved so perhaps it is the connector strip, not the caps.

Saw someone advertising the fitment of a new strip for £25 on ebay - is there anyone else out there who offers that service?