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So today I switched on my printer like I have for the longest time.

And the LCD flashed on, then went dead, and stayed dead.

The fan on the Power Supply keeps spinning.
I think I can connect to the Arduino part of the board via serial, but i'm not sure.
The electronics show no sign of function.
The main power line to the board shows 12v on a multimeter.
The fuse on the board is not blown.
I didn't hear any popping sounds or see smoke.
The temperature probes do not appear to be showing temps.

Suggestions? I can;t test another power supply without cutting away the cables to use the connector that came with the Rostock Max.

Thanks

Try reuploading the firmware I guess? Sounds a lot like a blown fuse though... and there is more than just the 1 big one on the board. Not sure exactly how many smaller ones there are though.

Ok, the fuse at F3 blew.

I moved the good fuse at F2 to F3 and turned the printer on, it immediately blew.

I have a wait of a week for new fuses, idea what to do so I don;t blow them?

Thanks

If it's blowing immediately, you have a short somewhere, most likely the Hotend wiring.

Polygonhell wrote:If it's blowing immediately, you have a short somewhere, most likely the Hotend wiring.

I suppose that's possible, but doesn;t make any sense. The hotend has been working perfectly.

How can I test this?

I feel rather helpless, I don't know what else i'm going to need, or what I can test.

Thanks

Do you have multimeter or simple wire tester?

Hotend shows 4 ohms, heated bed shows 1.2 ohms.

Look at the board layout diagram and it'll tell you what things are routed through the F3 fuse. Check everything it lists.

g.

The F3 fuse controls the logic on the newer cards meaning that if it blows the card leds etc will not light but it also controls the hotend and the fans.
My guess from what you have written is that one of the fans has a short on the wires.

When I changed out a failed PEEK fan, I noticed the insulation on its leads was scraped away where it rubbed on the melamine when the PEEK fan shroud was inserted or removed. It hadn't caused any problem yet, but was hidden from view.

You can disconnect the hot end wiring (heater, thermistor, PEEK fan, and layer fan(s) from the RAMBO and then use a multimeter to check for short circuits within each item or between them.

Earthbound wrote:When I changed out a failed PEEK fan, I noticed the insulation on its leads was scraped away where it rubbed on the melamine when the PEEK fan shroud was inserted or removed. It hadn't caused any problem yet, but was hidden from view.

You can disconnect the hot end wiring (heater, thermistor, PEEK fan, and layer fan(s) from the RAMBO and then use a multimeter to check for short circuits within each item or between them.

First, just do a good visual inspection of everything before you start pulling connections. If that doesn't yield anything, follow the instructions above and test each connection against all others looking for continuity where it shouldn't be. Try not to move any wiring more than necessary though as you could separate the shorted points making it much more difficult to find.

For that i would recommend starting at the rambo side.

Remove the connectors one by one and put a continuity meter to them.

I got some new fuses, and removed the hotend and fans from the Rambo.

f3 still blows.

Suggestions?

Thanks

Lasivian wrote:I got some new fuses, and removed the hotend and fans from the Rambo.

f3 still blows.

Suggestions?

Thanks

Check the connections at the Rambo ? A strand of wire may be making sparks with it's neighbor.

Did you check for continuity across the cooling fan wires that are soldered to the board to make sure those aren't shorted?

Have you checked ALL the wires? Taking the Rambo in and out tends to put some wires in awkward positions. The suggestions here are good. Follow them. I just went through a F3 fuse blow situation myself. Mine ended up being easy to find. Good luck with your search!