Ramps 1.4 Mk1 heatbed atx power supply stops

So have Prusa mendel..
RAMPS 1.4 Arduino...
Mk 1 Prusa heat bed..

Whenever I set temperature through pronterface, (either by mac or linux), the atx power supply stops.. ie fan stops everything stops...

The wires going to the heatbed come out of D8.. the 11A going in to shield as normal.. ( Have checked polarity etc..)

Prior to it stopping red LED behind mosfet lights up.. No LED on heatbed at all.. Thermistor for heatbed temp is plugged in.

Have directly connected the bed to 11A power supply and don't get the problem.. i.e. LED on bed lights up and it heats...



Any advice most welcome

Cheers Will

Enough amps in psu too supply bed? What wattage is the psu

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Check my rubbish blog for my prusa i3

up and running
[3dimetech.blogspot.co.uk]

It is 500 W Eagle Voltas..

It heats up the bed when directly connected, i.e. not going through the RAMPS..

Have now tried it with a lower bed temperature aim ie 30 oC but it still trips the power..

Think this is now solved..

I didn't have any load on the 5V rail. The ATX monitors it and shuts down if no load

. Now stuck a 12V, 20W halogen on that rail so it lights up and I can see visually..

Sometimes just asking the question helps in providing the solution..

Cheers Will

Hello,

I am facing same problam. have 450W SMPS, can you please explain how can i solve this issue with images if posible.

Regards,
Chandru.

You may do better starting a new thread as opposed to latching onto a dead one.

By SMPS do you mean an industrial +12V only supply or do you have an ATX supply intended for use in a PC? If it’s an industrial +12 only supply rated at 40A it should run anything on a printer with ease. Your problem is likely the 5A PTC fuse cutting out rather than the supply. On a multi output ATX supply there can be some odd issues that are very specific to them.

I am using power supply intended for use in a PC, a multi output ATX supply.

If you are running an ATX supply, 450W probably isn't big enough. You need a supply with at least a 22A rating on the 12V rail(s). A rating of 30A would be better. If your supply is cutting out, it's not able to put out the current you need. I would suggest spending the $45 that an industrial 12V 30A supply costs.