Gen 7 heat bed connector melted?

Hi, I have a 1.3.1 gen 7 board. The heatbed lost connection and there was a burning smell from the board. After closer inspection I found the white plug has melted through and the pin isn't making connection anymore.. Is this a known problem or is it the 34 degrees C ambient temperature I am printing in causing heat issues with the board?

Suggestions for larger plug or more heat resistant plug?

This connector is very close to it's capabilities, so a bit dirt can make the connection poor enough to make it overheat.

- Make sure the crimp connectors are clean and soldered to minimize electrical resistance.

- If this still doesn't work, consider a screw terminal. The holes in the PCB are already there.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Phizinza Wrote:
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> After closer inspection I found the white
> plug has melted through

Do you mean the connector for the power source or the output connector?
In my case i use screw terminals. They should work up to 10A.

Output from the board to the heat bed has melted.

I'll have to get a screw terminal as I soldered it and it is clean.

Thanks.

I used wires and a 12A spec two contact connector from radio shack, thinking about using screw terminals for the next board myself
terramir

I have had the same problem with my Gen7 board and heated bed connector. I would like to replace the present headers with screw terminals, but can't find any of the correct pitch (3.96 mm). I can find screw terminals with 3.81 mm or 4 mm pitch - but not 3.96 mm. Obviously using a 4 mm pitch header in this context wouldn't be any problem, but it seems slightly perverse (and might cause problems if there were a larger number of contacts).

I've tried Farnell and Radionics - digikey / mouser have too high postage costs / minimum orders.

P.S. The alternative heated bed connectors suggested on the Wiki ( [reprap.org] ) have the incorrect pitch. (I'll try to fix if I have time.)

Edited 1 time(s). Last edit at 05/28/2013 10:30AM by dslc.

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Semi-commercial engineering | Reprap diary

gen7 1.3.1 has enough pad width that you could drill holes are a 5mm distance in order to put a screw terminal and replace the header in question.
Also look into upgrading ( cutting traces and adding wires in order to have the thermistors be powered my 5V vsb :p
terramir

I put screw terminal on the heatbed output, I also did the standby power mod for the thermistors. Not my only problem is I sometimes have a lose connection on the hotend. I've used chocolate block terminals to connect it, but even they are getting so hot it is melting a bit... Still, with this new lot of ABS I have I seem to be able to print it at 20degrees less, so not having as many problems with that.

While the difference between 4 mm and 3.96 mm is neglibile, there should also be holes 0.2" inches (5.0 or 5.08 mm) apart. Look from the bottom side, they're close enough to the 4 mm spaced ones to be covered by the header.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

@Terramir: Cheers. I went with the 5.08mm as per your / Traumflug's suggestion and have a safer electrical setup with 17.5 A screw terminal headers as s result.

@Traumflug: You're quite right: the holes are indeed there (I'm embarassed I missed them). The only catch is that I needed to widen the diameter of the holes to accept the through-hole leads of my new headers. That was no big deal though - a 1.2mm drill bit did the trick in my case. Good job and thanks for your help!