Need Help: bq Prusa i3 Hephestos - heated bed upgrade not working

[elGordo]

Hi - posting in a separate thread although similar issue to the previous posting.

Purchased the heated bed and power supply upgrades from printme3d.com so I assume that they are kosher upgrades.

Power supply seems fine, but the heated bed won't warm up at all.

The bed is definitely functional, but does not get switched on by the printer (no voltage at D8). If I briefly short out the pins of the MOSFET then the bed starts heating, but I'm not sure whether that indicates that there is a problem with the MOSFET or whether the problem lies elsewhere, e.g. with the thermistor and the connections to the board. I believe that is it connected correctly, next to the thermistor pins for the extruder. Following another suggestion elsewhere, I just swapped the thermistor around for the extruder thermistor on T0 and it looks like it is definitely working, but doesn't appear to be on T1.

The printer has been flashed (using Cura and the latest BQ download) to 1.4.2 #247.

Whenever I attempt to print off something requiring a heated bed, the screen shows the nozzle heating up and also states that the bed is heating, but nothing happens to the bed. It stays the same ambient temperature.

Note - the LCD display does not show a temperature at all for the heated bed - I have seen this shown on pictures of other screens, but I'm not sure whether I should be seeing it with the bq firmware - there are no values or 'H' shown at the upper right of the LCD screen. Is this correct for the latest version of the software or does it indicate that I am not running the correct version?

Hope you can help, I've now spent two days on this and searching various forums, but nothing seems to work. Very frustrated.

many thanks

elGordo(n)

[Raptorfx]

Hi. If it is not even displaying the temperature I assume that it is not enabled in the firmware. Is there any special download at BQ which includes heated beds?
I compiled Marlin myself for my I3, so not sure on what BQ offers.

In you host software (Reptier/Pronterface/Octoprint/...), what does it return when you execute "M140 S55" ?

[elGordo]

Many thanks - bq themselves got back to me too. Looks like the advice I received from printme3d was incorrect - they advised to use Cura flash the latest download from bq. However, this didn't have any of the settings for heated beds.

bq themselves advised to use https://github.com/bq/Marlin/releases/tag/1.4.2

and manually change:

#define TEMP_SENSOR_BED 0 <== change the valor to 1

Verify that #define MOTHERBOARD have the valor 33.

They also pointed me towards this for full details on how to do it:

"Here you can find an article that may helps you but, regrettably, it's only in Spanish: http://www.mibqyyo.com/articulos/201...a-3d-prusa-i3/ "

In summary, it turns out in the end I'd built everything correctly, but that I was running with the wrong firmware. I lost a day due to dodgy advice.

A pointer towards my problem - if you're running on the correct firmware and also got the heated bed switched on, you should see a temperature for the heated bed showing in the upper right of your console - there will be and 'H' followed by two values, the current temperature and the target temperature, similar to what you see for the extruder nozzle.

Hope that helps for anyone experiencing similar pain.

thanks

Gordon

[Raptorfx]

Glad you worked that out that quickly. And with only one day you are quite fast for solving this actually!

[geab]

Which Cura version are you using? and could you make the firmware available to download - I am not so good at spanish :-)