hotbed/extruder is not heated up(GT2560/GTM32/sanguinololu)

[William]

I checked again and noticed that a component on the chip is damaged (see pic).I checked the gt2560 circuit diagram, but couldn´t find anything labeled Q4. Might be a circuit breaker? Any idea´s? Also i don´t know if this component cuaused the overload or the overload caused this thing to fail... Anyway, if anybody knows what kind of component this is and if it´s fixable, I will be thankfull for any help. Meanwhile i think I better order a new gt2560

Hi,
The component is a FET(Field Effect Transistor) which is named for A5SHB,the details about its specifications:
SOT-23,AP2305AGN,PMOS
You can buy a new one and solder it on the board.

[Esteban]

Hi,

I just bought a M201 I3 3D printer. I have problems heating up the hotbed. Basically it doesn't heat up at all. I have been following this thread and checking the machine. I have encountered that when reading the MOSFET when NOT heating the hotbed up is 1,1V. When I turn up the heating manually it stays as 1,1V. I have no problem with the hotend, when not heating up the MOSFIT reads 1,1V and when heating it up it reads 4.8V. It is a different behavior than the described in this thread (for a GTM32) but it heats up the hotend.

Also, the thermistor (NTC) of the hotbed is marking 0 degree. I exchanged the connection on the motherboard for the one of the hotend, but the thermistor of the hotbed continued on 0 degree while the one of the hotend showed the right temperature.

Any help appreciated! Cheers.

[Esteban]

Hi,

I just bougth a M201 I3 3D printer with GTM32 board. My hotbed is not heating up. I've been following the steps on the this thread. When I measure the voltages in the mosfet (as indicated in the thread) I read 1,1V when not trying to heat it up. When I try to heat it up the mosfet still reads 1,1V.

The hotend does heat up nicely, but I have a different behavior than the one described here. When I measure the mosfet without trying to heat it up it reads 1,1V, when I heat the hotend up the mosfet reads 4,8V.

Also, the thermistor for the hotbed shows 0 degree on the LCD. The thermistor for the hotend works well. I swapped the thermistor's connector on the board and the one connected to the hotbed still shows 0 and the one connected to the hotend shows the right temperature.

Any help welcomed, best regards,
Esteban

[William]

Hi,

I just bougth a M201 I3 3D printer with GTM32 board. My hotbed is not heating up. I've been following the steps on the this thread. When I measure the voltages in the mosfet (as indicated in the thread) I read 1,1V when not trying to heat it up. When I try to heat it up the mosfet still reads 1,1V.

The hotend does heat up nicely, but I have a different behavior than the one described here. When I measure the mosfet without trying to heat it up it reads 1,1V, when I heat the hotend up the mosfet reads 4,8V.

Also, the thermistor for the hotbed shows 0 degree on the LCD. The thermistor for the hotend works well. I swapped the thermistor's connector on the board and the one connected to the hotbed still shows 0 and the one connected to the hotend shows the right temperature.

Any help welcomed, best regards,
Esteban

Hi,Esteban
You mean the thermistor for the hotbed showed 0 degree before,and after the swapping it still reads 0 degree(now the port for hotbed connects to the thermistor for hotend)?
If so,your thermistor didn't have a good connection to the connector of the board,that is to say,the thermistor wasn't detected by the board.You should check the board by making the thermistor open circuit and short circuit,refer to the post for GT2560:
http://www.geeetech.com/forum/viewtopic ... 23&t=17030

[Esteban]

hi William,

Thanks for your response.

what is happening to me is the following>

In the initial connection I have:
HotEND thermistor connected to hotEND port on the board
HotBED thermistor connected to hotBED port on the board
On the LCD display: hotEND termperature "18/0"; hotBED temperature "0/0"
I swap the connections on the board:
HotEND thermistor connected to hotBED port on the board
HotBED thermistor connected to hotEND port on the board
On the LCD display: hotEND termperature "0/0"; hotBED temperature "18/0"

Please your comments.

I will review the post you recommended me.

Thank you

[ggg666]

Hi,Esteban
Two findings:
1.You slots for the thermisters on the board is OK.
2.The thermistor for heatbed has a short circuit,you should check if its two pins are connected.BTW,the thermistor is at the bottom of the heat bed.

[rotormansa]

One other thing to check is the power supply voltage. My power supply was set to 11 volts. My hot bed took over an hour to heat 100. Increased the voltage to 12.8 volts and now 105 is reached in 10 minutes. Had to only make small adjustment to the trim pot on the power supply. All works well and the 2560 vreg is good to 26 volts. The fans do run a little faster, but it shouldn't be an issue

[Gupu]

I have a similar problem as commpoly3d...
When I turn on the power supply and board, the green LED for heatbed turns on. Then, if I manually set a temperature for the heatbed, the green bed turns off. The red LED near the heatbeds pins never turns on but the LED embedded on the actual heatbed flashes once.
Is this a problem with my power supply?? The fuse and MOSFET seem to be fine.

[rotormansa]

@Gupa.... check the voltage at the hot bed. You should measure 12V (or close) when the embedded controller LED turns on indicating the hot bed is heating. You state the LED on the hotbed flashes briefly when the embedded controller indicates the bed should be heating. If the voltage isn't near 12v when the hotbed should be heating then you may have a loose wire or bad wires causing a large voltage drop to the hotbed. You could swap the wiring to the extruder and hotbed; both circuits are the same, then manually turn on the extruder from the front panel, you should see the hotbed turn on.. if it doesn't then the wiring/connections or hotbed is bad.

[ggrshelton]

I purchased my Geeetech Aluminum Prusa I3 A Pro 3D printer & 3-in-1 control box on EBay from "geeetech-official" (Order #232045068959) and received it on March 3rd. So far I have printed about 0.75 kg of PLA filament. Yesterday my Hotbed stopped heating. When I took apart the control box, I discovered that the 15 Amp hotbed fuse connector was burnt. The fuse is ok, but connector is burnt. The connector is surface mount to PCB, so I can't solder on a new one. I have sent e-mails to the EBay seller "geeetech-official" and Geeetech Order Service. Is Geeetech willing to send me a replacement GT2560 control board? How can I repair the printer?