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Had my machine turned on, heating up the build plate for a while (it takes a bit to come to temp, especially when it's colder in the house like it is right now). Suddenly the machine blipped off and the LCD went dark, no power at all. Cycling the power switch gets a brief momentary flicker on the LCD, the fans twitch, then dark again.

Um... help?

Have you checked the Fuses on the board ?

If you find one to be blown, don't just change it, but try to find the issue that blew it off first.

The automotive fuse is good. I'm not sure what to look for on the smaller fuse (the tiny white one). It doesn't look discolored at first glance. What do I look for on that one?

The printer has been running fine for many months and this is the first distinct electrical problem I can recall. The *only* thing it was doing at the time this happened was heating the bed (target temp was around 110-120 deg, I think). It was sitting there, heating the bed, and then blip... nothing. No magic smoke, no ozone smell, no particular noise or sound when it happened, just like somebody cut the power.

GarageBay9 wrote:The automotive fuse is good. I'm not sure what to look for on the smaller fuse (the tiny white one). It doesn't look discolored at first glance. What do I look for on that one?

The printer has been running fine for many months and this is the first distinct electrical problem I can recall. The *only* thing it was doing at the time this happened was heating the bed (target temp was around 110-120 deg, I think). It was sitting there, heating the bed, and then blip... nothing. No magic smoke, no ozone smell, no particular noise or sound when it happened, just like somebody cut the power.

You need to carefully remove the small fuses and check if they good or bad with a multimeter on continuity setting or measuring resistance, a good fuse would show close to 0 ohms.

You may also have blown out your power supply.

Glacian22 wrote:You may also have blown out your power supply.

Ugh... Rewiring this thing with a new PSU is not something I'd look forward to..

I'm using the stock PSU. Any fast way to check if it's the root of the problem?

Update: Tried turning it on via power switch again.

Turns right on and runs hot, straight and normal as if nothing happened.

Is there a hardware thermal cutout somewhere on the RAMBo that may have triggered that behavior, or possibly in the power supply?

Check your power switch. Sometimes the cables come a bit loose.

Another note on the possibility of it being your power supply...what you're describing of it powering off during heatup and then being able to turn it back on later is exactly what happened when my power supply was failing. You might try blowing some compressed air through it to clear out any dust that's keeping it too hot.

Glacian22 wrote:Another note on the possibility of it being your power supply...what you're describing of it powering off during heatup and then being able to turn it back on later is exactly what happened when my power supply was failing. You might try blowing some compressed air through it to clear out any dust that's keeping it too hot.

It's looking like that's what is happening. I turned it on a few minutes ago to get ready to start a print and it just blipped on me again. I really, really do not relish the thought of rewiring the PSU - although I think I'll use an externally situated 16 amp Xbox 360 PSU this time.

The power supply will drop out of the bottom of the machine - it's easily replaced.

g.

geneb wrote:The power supply will drop out of the bottom of the machine - it's easily replaced.

g.

?

Mine is bolted in one of the interior cavities inside the lower base. Not sure I understand what you mean by dropping out the bottom?

I have a relatively early Max, just after the changeover from the side to the top mounted extruder motor.

Ah, ok.

Still, the power supply in the v1 comes out easily as well, just not AS easily.

g.

Ok - I grabbed an old Xbox360 power brick to use as a new supply, since it has a buttload of amperage on the 12v supply (16.5 amps!). Any tips or warnings about using one of these? I've got a pinout diagram for it, just want to make sure I avoid any less-obvious pitfalls.

The X-Box power supply may work for a while but although 16.5 amps sounds like a lot, the heat bed can draw 12 amps by itself.
I personally suggest the 12 volt 30 amp supplies you can find on Amazon or Ebay or SeeMeCNC as the power supply. If you want
a heatbed that gets to temperature quickly I would use a 24V min 20 AMPS as the power supply to the heat bed. It has been documented
on this forum many times and consists of the 24V power supply and an SSR to the heatbed. If you are more patient I would recommend the
power supply (12V) that SeeMeCNC is now selling, it is new and supplied with the new kits. http://www.seemecnc.com/collections/par ... supply-kit" onclick="window.open(this.href);return false;

Whoa, 30 amps?

I don't even have a circuit in my house that can supply 30 amps (they're all 20 amp service). Beyond the heated bed - I'm assuming 12amps is peak load - just how much beyond that do the hot end, electronics, and steppers need?

GarageBay9 wrote:Whoa, 30 amps?

I don't even have a circuit in my house that can supply 30 amps (they're all 20 amp service). Beyond the heated bed - I'm assuming 12amps is peak load - just how much beyond that do the hot end, electronics, and steppers need?

Well, 30amps at 12 V, is only about 3 amps at 110v from your mains supply (hence the thin little mains wires feeding the PSU, and the big beefy 12v cables feeding the rest of the printer, higher voltages can move the same wattage on smaller conductors)
30amps at 24v is going to be ~6A at 110v. Again, very approximately and not allowing for PSU efficiency etc. Or I may be completely wrong, it's late, I'm tired.

https://www.quora.com/Whats-the-differe ... -and-volts

OK... I tracked down a dedicated 12v 30 amp power supply. I pulled up the Max v2 assembly guide to check how to wire it up, and noticed the Max v2's RAMBo is different from mine.

Can I wire mine the same way, or is there something specific I should know ahead of time about how to correctly wire up that kind of PSU to the v1 RAMBo? I don't have money for a replacement board right now so I have to get this right the first time.

The RAMBo boards haven't changed in layout (significantly) since they were introduced.

Can you post a photo of your board?

tnx.

g.

geneb wrote:The RAMBo boards haven't changed in layout (significantly) since they were introduced.

Can you post a photo of your board?

tnx.

g.

On closer inspection (read: I actually bothered to go stick my nose in the electronics bay rather than going from memory), you're correct; they're the same board. I blame newborn-related sleep deprivation.

I'll follow the v2 wiring diagram. Thanks folks!

Congratulations on the tiny human, and good luck with the printer. It should go fine, and hopefully will make plenty of useful and fine things for a long time to come.

Please let us know in a few days how the new power supply is working for you.
I don't expect problems but I like to follow up and I am curious.
Happy Printing!

Will do, as soon as I can get it installed.

Kiddo #2 (the new one) is up most of the night with acid reflux and nursing latch problems (he's got what's called tongue-tie, where he can't latch onto a nipple properly). Makes for long nights and days I don't remember much because I'm asleep or close to it.

On the PSU I picked up, there is a voltage tuning knob - should I even touch that? I looked through the v2 build manual and didn't see anything mentioning it, and the photos showed the same adjustment knob on the v2 stock PSU.

GarageBay9 wrote:Will do, as soon as I can get it installed.

Kiddo #2 (the new one) is up most of the night with acid reflux and nursing latch problems (he's got what's called tongue-tie, where he can't latch onto a nipple properly). Makes for long nights and days I don't remember much because I'm asleep or close to it.

On the PSU I picked up, there is a voltage tuning knob - should I even touch that? I looked through the v2 build manual and didn't see anything mentioning it, and the photos showed the same adjustment knob on the v2 stock PSU.

It is normally not necessary to touch the voltage adjustment knob on the power supply. You would need a volt meter to set the control properly and it is not to be concerned with at this point.
In the half asleep condition that you are in, the printer should not be adjusted until you can focus on it only. I sincerely hope that your child number 2 gets better which means a better life for your family.

IT LIVES... Plugged in the PSU and it lights and runs. The Max boots and drives the delta carriage nicely. Haven't checked the heated bed yet, but I don't expect any issues - I didn't touch that wiring.

Just need to figure out how to neatly mount the new PSU in the gen 1 chassis, wire up the e3d cooling block fan, reattach the PLA layer fan leads, and remount the fan I had blowing on the stepper drivers to keep them cool.

Suppose I should tighten the heater block on my hotend too, it has some rotational wiggle after I ran it up to 300c to print weedwhacker nylon.

But hey, back in business! Thanks for the help in a long, slow, not-very-dramatic drama, everybody. : )