RAMPS died after solid year and a half of operation

Lately my RAMPS board has been acting very strangely. At random times during printing, the RAMPS will stop sending voltage to the heated bed. I tested, and I am getting 12 volts into the RAMPS, I also see 12 volts on both sides of the fuse. I just don't see 12 volts on the output of the MOSFET. My first thought was that a wire had come loose, and sure enough, pulling on the wires caused the LED on the output to light up and the voltage to turn on, so I redid all of my screw-in connections. But if happened again. This time, I pulled the board, repaired what I though looked like a bad solder joint, checked all connections and put everything together. It still failed, so I replaced the MOSFET, and it still failed. This time, I noticed that if I just seated the board a little better into the arduino, that it came on, so I thought that was it. But when I tried to print something, the bed turned off again and no amount of pushing/pulling would get it going again. I didn't know what else to try, so I went to Lulzbot and ordered a new RAMPS board. Should be here in a couple of days, but I'd sure like to know what happened to the current board.

Does anybody know of anything else I could try?

Given that you pressed on the board and it started working for a time, it could either be a damaged RAMPS board (pad or via damaged so it's intermittent), a damaged socket on the Arduino (pin bent internally), or maybe a damaged Arduino board (pad or via damaged). In any case, it sounds like it was caused by mechanical stress, probably when removing the RAMPS board.

I would redo the solder connections on the D8, D9 and D10 pins on both the RAMPS board and Arduino.

Is the 15a socket on the Ramps board discoloured from overheating which could cause bad continuity?

Also, the output of the mosfet is actually 0 volts, in other words, when it's switched to power the bed, it grounds the return path of the heater bed.

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Waitaki 3D Printer

You mean the 11Amp socket? Yes - the power connection from my power supply for the 11 Amp rail - specifically the positive side - is discolored from overheating. Other that that, there seems to be no evidence of overheating anywhere else on the board.

One further note - I needed to make a part for the local high school FRC robot, and it was going to be a 5 hour print. I was afraid to babysit such a long print, but I needed to get it done prior to this week's competition. I am in the process of making a second printer, but it is not quite ready to go, so I "borrowed" that printer's RAMPS and put it in my original printer, and it is working just fine. I still have about 2 hours to go in the print, but the temperature is holding steady.

As I mentioned above, my new board is on its way from Lulzbot, but when the dust settles, I'm going to go over the bad board more closely to see if I can figure anything out.

The connectors on the RAMPS boards sold by some of the cheaper players are well..... Crap. Same applies for clones of many of the other boards. If you're not buying from a decent company that puts reasonable connectors on the boards, I suggest you replace them.

Specifically the connectors that go to the heated bed tend to be slightly sub-par and may not even be specced for the ~10A that flows through the heated bed. I've seen many connectors that look very similar and yet differ in current capacity by a much as 7A (eg: 15A vs 8A rating). The lower the current rating, the more likely they'll fail.

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jbernardis
You mean the 11Amp socket? Yes - the power connection from my power supply for the 11 Amp rail - specifically the positive side - is discolored from overheating. Other that that, there seems to be no evidence of overheating anywhere else on the board..

Yes, 11A of course, my error. I had that problem once - caused by a slightly loose clamping screw. I managed to clean out the socket and re-wire the connection - been all good since.

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Waitaki 3D Printer

Waitaki - you hit the nail on the head. A few day after putting in the new RAMPS, I again had issues with the temperature dropping. When I jiggled the wires going to the bed, the LED came on and it started to work, so I replaced the wires. A few days later it happened again, but this time, jiggling the wires didn't help. Finally, quite by accident, I pushed on the power connector mentioned above and everything started working again. So I replaced the plug on the power connector and I have been solid for over a week now. The good news, perhaps, is that I now have a spare ramps board. As for the connector, I have attached a picture. It is quite dramatically discolored. I have purchased a few to have on hand.

Maybe a re-design is in order - or they need their own fan!

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Waitaki 3D Printer

I never have understood why they use those connectors on the Ramps. it not like we dissconnect them often. a good soild screw mount would work nicely, and I would think be a bit cheaper(pricewise).
I ended up replacing mine with one of the 4 pin power connectors from a ATX power supply, and soldered the leads to the board. the added bonus to that is adding a fan, most of them come with the inline 4 pin connector so it's plug and play( if you want it on all the time).

I would love to see a re-design of the ramps. different power connectors and get rid of those silly fuses, and replace them with a replacible fuse,again a cheaper solution.

Searching on digikey, you CAN find these connectors rated for 16 Amps. The one that melted down on me is clearly marked 10 Amps. It was operating too close to its limit for too long a period of time.

cat.farmer: You might not disconnect them often, but I do.

As for a redesign, that was sort of what RAMPS-FD was all about, except going to a Due.

There are a lot of new electronics ideas out there at the moment, so I suspect the whole landscape will change in the coming months.

FWIW: On the boards I made, I used 16A ones. Never had an issue.

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Cefiar
cat.farmer: You might not disconnect them often, but I do.

As for a redesign, that was sort of what RAMPS-FD was all about, except going to a Due.

There are a lot of new electronics ideas out there at the moment, so I suspect the whole landscape will change in the coming months.

FWIW: On the boards I made, I used 16A ones. Never had an issue.

I would expect you to be the exception. Your involvement with new designs and testing, I could see why you are changing offten. but for the average user, I doubt they touch it after it is installed, until it melts.

I'm looking forward to what is coming next. including the RAMPS-FD.

Actually on the printer in question I don't change the board at all.

What I do a lot is move the machine and the PSU is a separate item. While I can unplug it from the PSUend , I don't like carrying the printer with a cable dangling from it, so I remove it from the board end as well.

PS: I was - on average - moving it twice to three times a month for about 1.5 yrs straight - taking it to my local hackerspace.

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cat.farmer

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Cefiar
cat.farmer: You might not disconnect them often, but I do.

As for a redesign, that was sort of what RAMPS-FD was all about, except going to a Due.

There are a lot of new electronics ideas out there at the moment, so I suspect the whole landscape will change in the coming months.

FWIW: On the boards I made, I used 16A ones. Never had an issue.

I would expect you to be the exception. Your involvement with new designs and testing, I could see why you are changing offten. but for the average user, I doubt they touch it after it is installed, until it melts.

I'm looking forward to what is coming next. including the RAMPS-FD.

Actually, I remove them fairly often too. But yes, many people may have no reason to do so. I'ts not such a bad idea as it keeps the contacts 'clean'.

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Waitaki 3D Printer