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I just started a print, laid down one perimeter, then shut off. I flipped the switch off then back on, I get a quik lcd light up then goes back off. The little led light on the Rambo also flicks on then off. I honestly have less than 60hrs of print time on this thing. Ive replaced the Rambo, pulley teeth, lcd adapter, added the glass plate, and all I have to show for them is 2 ok prints and 3/4 roll of bad to incomplete PLA prints.........This sux.

When you turn on the power supply, does the fan spin up? Double check all your wiring to make sure there are no loose connections. Use a voltmeter to ensure you're getting the right voltage at each connector pin coming from the power supply.

I agree with the previous poster, most likely issue is the PSU, it could have failed, or you might have a short that's resulting in it shutting down.
Verify the fan on the PSU is running and you're getting 12V at the input to the board.

I've killed 2 power supplies in my Rostock. If you have to replace it, get one that has a higher amperage rating on the +12v rail. I think the stock supply is rated for 16 or 18 amps, so I bought one that does 25 amps and I haven't had trouble since.

bad news, its the PSU.....good news, i have another fan for the printer?

A short word of warning on replacing the PSU, not all ATX power supplies work well as power supplies for printers, some contain safety circuits that require a load on the 5V line before delivering significant current to the 12V line.
Unfortunately it's basically impossible to tell if a PSU has the circuit unless you try it.

Personally I would replace it with a none ATX 12V PSU unless you can get a referral of a known to work PSU.

Polygonhell wrote:A short word of warning on replacing the PSU, not all ATX power supplies work well as power supplies for printers, some contain safety circuits that require a load on the 5V line before delivering significant current to the 12V line.
Unfortunately it's basically impossible to tell if a PSU has the circuit unless you try it.

Personally I would replace it with a none ATX 12V PSU unless you can get a referral of a known to work PSU.

How much of a load is required? Wouldn't the 5V used to power the Rambo qualify as a load?

The RAMBo runs on 12-24 volts, or up to 35 with the 1.2 update, so not really...

dpmacri wrote:

Polygonhell wrote:A short word of warning on replacing the PSU, not all ATX power supplies work well as power supplies for printers, some contain safety circuits that require a load on the 5V line before delivering significant current to the 12V line.
Unfortunately it's basically impossible to tell if a PSU has the circuit unless you try it.

Personally I would replace it with a none ATX 12V PSU unless you can get a referral of a known to work PSU.

How much of a load is required? Wouldn't the 5V used to power the Rambo qualify as a load?

Usually over an amp is needed on the +5v rail to stabilize the power supply for the ones that need it. 10 ohm 10 watt resistors from radio shack are a common recomendation, just tie the ceramic brick to the PSU case for passive cooling.

lordbinky wrote:

dpmacri wrote:

Polygonhell wrote:A short word of warning on replacing the PSU, not all ATX power supplies work well as power supplies for printers, some contain safety circuits that require a load on the 5V line before delivering significant current to the 12V line.
Unfortunately it's basically impossible to tell if a PSU has the circuit unless you try it.

Personally I would replace it with a none ATX 12V PSU unless you can get a referral of a known to work PSU.

How much of a load is required? Wouldn't the 5V used to power the Rambo qualify as a load?

Usually over an amp is needed on the +5v rail to stabilize the power supply for the ones that need it. 10 ohm 10 watt resistors from radio shack are a common recomendation, just tie the ceramic brick to the PSU case for passive cooling.

Good point Lordbinky, those suckers would get mighty toasty warm.

lordbinky wrote: Usually over an amp is needed on the +5v rail to stabilize the power supply for the ones that need it. 10 ohm 10 watt resistors from radio shack are a common recomendation, just tie the ceramic brick to the PSU case for passive cooling.

If you tie that rail with a 10 ohm resistor, you're giving it an extremely easy return path. It will waste loads of electricity.

626Pilot wrote:

lordbinky wrote: Usually over an amp is needed on the +5v rail to stabilize the power supply for the ones that need it. 10 ohm 10 watt resistors from radio shack are a common recomendation, just tie the ceramic brick to the PSU case for passive cooling.

If you tie that rail with a 10 ohm resistor, you're giving it an extremely easy return path. It will waste loads of electricity.

What would be a better alternative? It would be nice to power something on the Rostock to load the 5V rail. Any suggestions?

Best solution would be to get a power supply that doesn't have that handicap. Failing that, try tying +5V to ground through a 100K or 10K resistor, or through an LED and an appropriate resistor. (Bonus: You get an extra light.) If resistors and LEDs won't move enough current to wake up the 12V rail, I'd just get a different PSU.

Try to think about electricity like water trying to find its own level... a 10 ohm resistor is way easier to go through than a RAMBo full of 100,000 ohm resistors and so forth. The 5V rail would wind up dumping all kinds of current through that resistor for the whole time the system is on, as though you hotwired your heated bed so that it was on full tilt all the time. You could probably stand in front of your electricity meter and watch the dials move.

Eaglezsoar wrote:
What would be a better alternative? It would be nice to power something on the Rostock to load the 5V rail. Any suggestions?

LOTS of LED accent lights! And put the whole thing on a turntable!

I think I read once you could connect an old CD drive and it would be enough load, I never tried that solution though.