SoliForum - 3D Printing Community — Heated bed does not heat up anymore

Re: Heated bed does not heat up anymore

null@example.com (kszwab) — Wed, 25 Mar 2015 22:05:51 +0000

I could not get a solder hold, so I cleaned a larger area, soldered, failed, then glued it as tight as possible and soldered a short wire to the initial failed point to relieve the mechanical stress. Figured the downforce from the glass will hold it in place, hopefully.

Re: Heated bed does not heat up anymore

null@example.com (carl_m1968) — Wed, 25 Mar 2015 02:23:50 +0000

kszwab wrote:

Open circuit measuring from the wires side with the board disconnected.
I took the glass bed off and I can see that one wire is off since they used HUGE blob solder points instead of spreading the twisted wires on a wider area and doing an elegant spread solder to maximize the contact area, better current flow and better mechanical leverage.
I guess in time the pretty high current cooks off the thin copper at the contact point and falls off.
Too tired to fix it tonight, will take it off tomorrow slowly to do it right and try to resolder it on a wider area to avoid the problem in the future.

There is a reason behind the blob solder. The heater substrate is acetate film it will melt if the heat of a soldering iron is kept on it long enough to actuallt flow the solder. So they do a quick tack and hope it is enough to hold.

Re: Heated bed does not heat up anymore

null@example.com (kszwab) — Wed, 25 Mar 2015 02:20:12 +0000

Solder does not stick to the heater bed filament. I used rosin core solder, but...

Re: Heated bed does not heat up anymore

null@example.com (kszwab) — Tue, 24 Mar 2015 04:00:50 +0000

Open circuit measuring from the wires side with the board disconnected.

I took the glass bed off and I can see that one wire is off since they used HUGE blob solder points instead of spreading the twisted wires on a wider area and doing an elegant spread solder to maximize the contact area, better current flow and better mechanical leverage.

I guess in time the pretty high current cooks off the thin copper at the contact point and falls off.

Too tired to fix it tonight, will take it off tomorrow slowly to do it right and try to resolder it on a wider area to avoid the problem in the future.

Re: Heated bed does not heat up anymore

null@example.com (kev0175) — Sun, 22 Mar 2015 22:27:15 +0000

In the back of the bed there are 2 wires both should be black and if you open the back of the printer you can see the wires on the left side of the board just look for the 2 screws with the black wires.

Heated bed does not heat up anymore

null@example.com (kszwab) — Sun, 22 Mar 2015 20:35:21 +0000

Never ending story of good Davinci products. Suddenly on one of my Davinci 1.0's the heated bed does not heat up anymore. Stays at 31C. Printed fine, then next print never heats up the bed.

Doing a calibrate does not heat up the bed, either.

Loose connections ? Can the wires feeding the bed heater break because of the up/down movement ?

Which wires do I need to check ? The black ones going to the bed ?

I do not see a connector, do I need to trace it to the board and disconnect from there ?

What should be the resistance of the heating element ?

Is this a common issue with the heated glass bed or an issue with the driver from the board side ?