Geeetech

Posted: **Thu Jun 11, 2015 4:57 pm**

Hi,

I contacted the seller on aliexpress where i bought a Geeetech Prusa i3 Pro B, he said i needed to ask here for quicker help, from an engineer.

My question to him:

My heatbed is not functioning normal. Didn't use it since the Sanguinololu got way to hot, and with PLA it's not necessary.
But now i wanted to start with ABS, but i can't because the heatbed makes the controller way to hot (even with a 30*40*40mm server fans which has 5 times more airflow then the provided one).
If i search the forum of geeetech i see it should be at least 1.2Ohm:
http://www.geeetech.com/forum/viewtopic ... 418#p24186
I measured mine and i get only 0.2Ohm, so it draws 6 times more current then it suppost to do (i checked for short circuits, but can't find any)! Can u sent me a replacement?
Kind Regards,
Stefan

I can give you my ordernumber, but don't know if i should post that in public...

Posted: **Fri Jun 12, 2015 8:52 am**

Normally, when heating the bed, the temperature of MOSFET will be very high even you have a fan.
How did you test the resistance of the bed? Is it like this:

: test hot bed resistance1.png (395.11 KiB) Viewed 8101 times

: test hot bed resistance.png (355.08 KiB) Viewed 8101 times

Posted: **Fri Jun 12, 2015 3:12 pm**

Yes i did it exactly that way, i saw your pics in an other topic.

I read out between 0.2 and 0.25Ohm. I can make a picture if you want, but at the moment i have a 12+ hours print job so i can do it later on...

Posted: **Sat Jun 13, 2015 9:06 am**

If it is the value you get after you unplug the heating wires, this hot bed is abnormal. Please contact the customer service, let them re-send you a good one.
How are other parts? Are they fine?

Posted: **Sat Jun 13, 2015 10:10 pm**

zhangxueyou wrote:If it is the value you get after you unplug the heating wires, this hot bed is abnormal. Please contact the customer service, let them re-send you a good one.
How are other parts? Are they fine?

Yes other parts are great, i'm printing a lot and all goes fine...

Wicht department should i mail? And can i refer to this topic?

Posted: **Mon Jun 15, 2015 10:22 am**

Tell the people who sold you the printer. Ofcourse you need to refer to (quote )this topic. Let them know this hotbed is not good indeed.

Geeetech

Heatbed not functioning normally (MOSFET overheats)

Heatbed not functioning normally (MOSFET overheats)

Re: Heatbed not functioning normally (MOSFET overheats)

Re: Heatbed not functioning normally (MOSFET overheats)

Re: Heatbed not functioning normally (MOSFET overheats)

Re: Heatbed not functioning normally (MOSFET overheats)

Re: Heatbed not functioning normally (MOSFET overheats)