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As you can assume from the title my power supply is deceased (or so i think)
All the sudden when I plug the ps cord in it doesn't turn on
I can't really think of anything that would cause this, all connections look good, extension cord works by itself
I think I would have noticed if the ps died from excessive load, and the last print i did worked all the way to the end
Does anyone have ideas about things i should check, etc.
Still under warranty?
I would check the fuse?
Amazon 30 day warranty is long gone, so no.Quote:
Still under warranty?
Unfortunately my hardware knowledge does not extend far into electronics, but I'm assuming that I would have to open up the case to do this? How do I find the fuse?Quote:
I would check the fuse?
Thanks for the fast replies
Has your power supply been making any weird noises before this?
I assume you're using one of the usual 12V 30-amps or so switching power supplies that fit the mounting hole pattern on the MakerFarm printers. The vast majority of such power supplies sold on Amazon, eBay, and 3D-printer sites are low-cost knock-offs of a Mean-Well brand power supply. Presumably built with lower quality components or inadequate quality control, a few threads here have unfortunately discussed these knock-off power supplies failing.Quote:
Originally Posted by spaceorange12
While some failures might be caused by something simple like a bad solder joint that could be easily fixed, it's probably best to consider the power supply non-repairable. The original Mean Well design does have a replaceable small glass tube fuse (under the cover, on the circuit board near the terminal block) on the AC input but that would most likely burn open only as a precaution when something else has failed in the power supply. Any problem downstream from the power supply should just shut down the output, not open the fuse on the AC input. You could check it and replace it if it appears burned open or tests as open with a meter. If the fuse is good or burns open again after replacement, I'd look for a new power supply.
Every power supply must have some kind of fuse for protection. Whether its internal or external. If you open it up I'm sure you could find a fuse. Open the power supply and send a picture here on the forum and we can help identify it for you.
Attachment 8028Quote:
Open the power supply and send a picture here on the forum and we can help identify it for you.
Let me know if anything is amiss.
Yep. My guess is that my 12" overloaded the PS and messed up something internally.Quote:
I assume you're using one of the usual 12V 30-amps or so switching power supplies that fit the mounting hole pattern on the MakerFarm printers.
Can you send me a link to one you prefer? I'd probably want a 40a one just to be safe.Quote:
If the fuse is good or burns open again after replacement, I'd look for a new power supply.
P.S. Yes the fuse is completely intact if you can't tell from the tiny pic
If the fuse is OK then it should be an easy fix. Have you checked the temperature sensor for continuity, the one stuffed into the green inductor?
I lucked into a used power supply, so I don't have a vetted source to offer. Someone else might. Meanwell doesn't appear to be publishing any "how to identify a fake Meanwell" info, so I can't offer that either.Quote:
Originally Posted by spaceorange12
There have been a few threads where options have been discussed. Some have done well with the low cost knockoffs - you just have to accept the YMMV factor. Your range of replacement options depends on whether you want the power supply to mount on the printer frame. If not, some have used an ATX-type power supply. This thread mentions a server power supply that has been adapted for free-standing use - http://3dprintboard.com/showthread.p...nt-Requirement.
40 amps would put you into a 500 watt or larger power supply. Just as another option, MakerFarm at least used to suggest using two power supplies on the larger printers, with one dedicated to the large heat bed on those printers. A smaller one can be used to power the electronics, motor, and extruder heater.
My PSU died. It was a 30 amp Astron PSU that now blows a fuse from some internal short. I will go figure out how to fix it, but in the meantime, I bought this one from some of the forum recommendations. With the 12x12, it only gest a little bit warm from the whole load. Have only been using it for 2 weeks, but so far so good.
http://www.ebay.com/itm/Power-Supply...0AAOSw14xWLQEp
costs a bit more than some ATX PSUs, but it is not super huge so that is nice too.
I really don't understand why they designed these things with heavy current low voltage heaters. You can get the cartridge heaters at pretty much any voltage, the Stratasys use 120 volt ones and I have a big selection ranging from 12 up to 400 volt. Same goes for the heated bed, mains operated silicon heat pads are available for a few pennies.
Switching AC is different from switching DC but it is no more complex and you only need a couple of amps of DC at the very most to power your micros and steppers. Altogether a lot cheaper and more reliable.
I got an ohm reading of 0.00, which indicates a short if I remember correctly.Quote:
If the fuse is OK then it should be an easy fix. Have you checked the temperature sensor for continuity, the one stuffed into the green inductor?
What do I do?
It should be 0, it is a safety thing that will go open circuit at some temperature, that will be written on it.
You do get them that work the other way round but I doubt this will be one.
If the fuse is intact then it really is unlikely to have failed and is most likely a broken connection somewhere.
Check the live an neutral inputs to the fuse. C4 next to the fuse is most likely across live and neutral so one leg shuld read 0 to the live pin and one leg 0 to the neutral pin. Is it a multi voltage input (110 - 230 or so) that you select somewhere or is it a multi voltage input, that will be specified on the sticker.
Yep, both legs on C4 read 0 to their respective pins.
My power supply has a manual switch to select between 110/220v inputs, I have it on 110v which is correct for my area.
I can't really offer a lot more but I do not think there is a lot wrong with it.
Check the 4 three legged devices that are fastened to the heat sink, two top right, two bottom middle. Are any of the three legs directly short circuit (0 ohms) both ways round. If they are then they are blown. What about the other thing plugged in just under the temperature sensor, is that to a switch or something or is it another sensor?
The resistor wedged between the two black capacitors at the top may have gone open circuit, check the value. Measure it with a meter and look at the colours on the resistor, work out what it shoudl be and see if it si correct.
All of the heat sink components test correctly.
The plugin under the temp sensor leads to the case fan.
The resistor between the capacitors measures 0 ohms, supposed to be a 270 ohm resistor.
I am just as confused as you are, but I'm ready to just order another if there isn't an easy fix.
I have come to realize that the fault does not lie in the power supply. I dug up another old power supply and tested it with the printer. This ps didn't turn on either. Any thoughts on what wiring problems might prevent a power supply from turning on? Note that the problem occurred while the printer was off so nothing changed between my last print and now.
A short between 12v and ground will keep the power supply from turning on. When it detects the over-current, the power supply will protect itself by shutting down the output. Well, at least most of these switching power supplies will.Quote:
Originally Posted by spaceorange12
What electronics suite do you have (RAMPS vs RUMBA vs. ?)? Remove all the 12V connections to the electronics, and then reconnect them one at a time. In otherwords, connect power for the electronics iitself first. If that works, then connect motor power if that is separate for your electronics. Then try connecting heater power, etc.
You might want to plug in the supply with nothing connected to it and see if it produces output voltage. Some switching power supplies need a load before they will turn on so this test may not do anything. But if you have voltage on the power supply with it not connected, you can start connecting one wire at a time and see when it loses power.
I think the 270 ohm may be 0.27 ohms so may be hard to get an accurate reading for depending on your meter.
Are you sure you have the multiplier right. It may be 270 across an inductor so should read zero anyway.
As Printbus says, if there is an over current then it will shut down before you even know it has come on.
Thanks for all of the help everyone has given me. I will try to answer all of your questions
Some specs:
RAMPS 1.4 w/ LCD
12" Heatbed w/ built-in relay
12v 30a power supply (RIP)
14awg wire for power connections (RIP, maybe)
Tests I've done:
Disconnected everything from 30a ps and plugged into power (ps still wouldnt turn on)
Connected old 20a ps to stock RAMPS (ps wouldnt turn on, but worked by itself afterwards)
Connected old RAMPS to old ps using my stock 14awg power wiring (neither would turn on)
Conclusion:
I think that my power wires are bad or broken. I am replacing them with some thicker 12awg wire and testing that now.
What kind of wiring did you use before? If it was some of the highly flexible silicone insulated stuff, one thought is you might overtightened cable ties or something and over time, the insulation was damaged.
It was some stranded wire with standard insulation, bought from home depot. I checked over all the wires, no sign of any damage. Very confused as to what the cause of this is.
I want to include my experience to help the community.
I recently had a power supply that died and I noticed some signs of it dying and wanted to include them here.
It started with an electrical whine whenever I would heat up the heat bed or the hot end by themselves. Once I would heat them together the whine would go away.
After this my power supply output a lot of noise when heating up and being used, kinda like the fan was on overload. Then today I attempted to print and the power supply made so much random noise that it was not bearable to use.
So I ordered another power supply (one of the potential knock offs of the Mean Well) from Amazon today. Thanks to one day shipping I have it installed and the noise difference is incredible!
Just be on the look out everyone, these potential knock offs don't last to long. I had my previous one for a year.
I got a big 40a ps off amazon and have that running now. Everything powers on and functions as normal except for the heated bed. When I try to bring it to temp, it doesn't even get warm and I don't hear the relay "click". I have it wired up the exact same way that I did before this whole mess happened, so the problem isn't the wiring.
Again, thanks for all of the advice and responses from all of you.
Have you checked the traces on the relay? Do they look burnt?Quote:
Originally Posted by spaceorange12
Nope. In fact all connections to the heatbed look just fine. Maybe something on the RAMPS is broken?Quote:
Originally Posted by BLKKROW
If you have the relay coil connected to the RAMPS D8 terminals, make sure you're still supplying 12v to the 11-amp power input on RAMPS. Some people have thought that since their heavy gauge wiring is now going to the relay instead, they don't need to supply power to the RAMPS 11-amp input. That input, however, is still needed in order for RAMPS to output the voltage required to energize the relay.
As a test, you could remove the relay coil wires from RAMPS and apply 12V directly to the relay wires. If that energizes the relay (and the heat bed warms up), you know for sure that there's something wrong the RAMPS hardware or in the firmware.
RAMPS has three outputs (D8, D9, and D10). The normal application has the heat bed connected to D8 and the hot end heater to D10. If D9 isn't being used for a 2nd extruder heater or print cooling fan, you do have the option of moving the relay control to the unused D9 terminal. A few have done this when they've fried the D8 MOSFET on their RAMPS. I think the pin assignment scheme has changed from the older Marlin firmware I'm familiar with, but it still should be a simple change. This swap only works if the relay is used. D9 can't supply the high current for a bed directly. Moving the relay to D9 has another small advantage in that this eliminates the need to supply 12V to the 11-amp input on RAMPS.
i have 12v going to all of the power connections on the ramps
my guess is the d8 mosfet is fried, but i will try the heated bed with my other ramps to make sure
ok everyone,
i tested with my other ramps, which worked. so i remapped the heated bed pins to D9 in pins.h on the stock ramps, and the whole thing works!
problem solved - hopefully.
thanks so much for all of your help and replies, im very impressed with this forum.
guess what? theres another problem.
when i tell the bed to preheat to 75˚ it blows past and just keeps heating until it reaches 90˚ at which point I unplugged it. Some people have had similar problems except their beds immediately do this when the printer is turned on. Mine only starts when I tell it to.
im going to make a new thread for this, see http://3dprintboard.com/showthread.p...6266#post76266