Heated bed not heating up anymore

[Mocco1301]

Hi Guys,

I need a second opinion on this as I fear the heating section for bed heating on the GT2560 v3 is dead. I seem to have a problem on my 2 week old A10. It has been working without fault for the last 2 weeks since I received it. Tonight I tried a print and half way through the print my printer shut down and did a reboot. When it start up again my head bed temperature kept on falling. I tried heating the nozzle and that worked fine. Everything seems to be working except for the heated bed. I have tried the following,

Tried to heat the bed via the LCD - Not heating

Tried to heat it in manual mode via the PC - Not heating

Checked that both shows room temperature like normal.

Removed the heat bed from the printer to inspect the soldered connections - Looked okay

Tested with a multi meter for continuity - okay

Tested the cable for continuity - Okay

Tested the Ohms on the + and - and found = 3.4Ohms

Tested the fuses on the GT2560 V3.0 - Both fuses are okay

With the board powered the is no LED light on "D9" - Not when im trying to heat up or with heating turned off.
Tested the Mosfet for the bed heater - Heating on - 0v on pin left hand pin, 5v on right hand pin. No voltage on either pin when not heating.
Is there anything else I can try and check?
What is the next step from here?

TIA

[Mocco1301]

Yep I sent them a detailed email with all the details last night. Just hopeful more than anything. I'm still printing though...now with blue 3M painters tape and a bit of luck!

[Mocco1301]

Any of the Admins that can help with this or get someone for Technical help to contact me?

Ive had one email from them asking to check the power supply is giving 24V even after saying the printer is powering up, its been dead quiet ever since.

[_kaktus_]

Hi


Okay, I've taken an interest in your problem.
You prepared a professional description of your problem and it seemed that you would manage to solve it.

Now I can see that you need further help.

In order to consult with us, we will need a piece of the schematic diagram.
.

hotbed+hotend_conn-GT2560-v3.png (71.09 KiB) Viewed 12737 times

.
The LED D9 you are writing about indicates that the mosfet transistor is switched on and the heating is started.

You have written that you have tested the entire heating circuit. OK.
So we know it should be working.
To be sure, set the multimeter to the DC measurement mode.
Find the negative pole on the HAET BED board. Connect the current meter to this pole and the ground potential in the main power connector.
Observe the indications of the multimeter.
Important: measuring range of minimum 10A.

When everything works as I expect it will confirm that the mosfet transistor that turns on the heating could be damaged. (Confirmation of LED D9 not lit).

If you haven't understood something because my English is weak, ask.
Please let us know the results of the test.

It is important to check the "HB" connector as well.

[Pi77]

Hello everyone!

Same problem here, i've got my A10 this week and the heatbed is not working. The LED D9 is not glowing when I try to heat the bed up.

Any suggestions?

Thank you!

[_kaktus_]

Hi.


If the D9 LED remains off, it may indicate that it is off:

• Fails to power the heated bed,
• Damaged NMOS3 transistor.

Check everything in order from the list to exclude each option.

[TMeeks]

I had a similar thing happen with an A10. After printing fine, it aborted a subsequent print a minimum temp error and the display showed the bed temperature as -14. It seems now that the reading of the temperature is erratic.

I opened access to the GT2560 V3 board and right now the D9 LEAD does come on. But, it's late and I don't have the time to see if it's a cable etc. this evening. I will try again tomorrow with the top off the board housing so I can view D9 through an entire print.

[William]

Hi.


If the D9 LED remains off, it may indicate that it is off:

• Fails to power the heated bed,
• Damaged NMOS3 transistor.

Check everything in order from the list to exclude each option.

Agree with Kaktus's points

[William]

I had a similar thing happen with an A10. After printing fine, it aborted a subsequent print a minimum temp error and the display showed the bed temperature as -14. It seems now that the reading of the temperature is erratic.

I opened access to the GT2560 V3 board and right now the D9 LEAD does come on. But, it's late and I don't have the time to see if it's a cable etc. this evening. I will try again tomorrow with the top off the board housing so I can view D9 through an entire print.

Waiting for your result

[3dprintings]

I have the same problem as Mocco1301 and i checked the heatbed manually. I connected it to a PC powercable and it Works. Now i think, its a Problem With The Mainboard. What can i do?
Do i have an Chance to repair It without soldering?
D9 is Not glowing, when i try to Heat IT Up.