WTB: LPKF E33 Mainboard - Page 1
Forum section: electronics / general

author: bartver
author_rank: Contributor
timestamp: May 06, 2020, 09:01:52 am
content: Hello,I acquired a E33 on ebay few years ago, used it regularly, but all of a sudden, when powering up it released magic smoke.....The fpga is broken, draws >1A when supplied 1V, basically a short, it smoked several powerconverters on the mainboard.So, i'm looking for a new mainboard : Circuit board SMCU IV embedded.i think it's also used in other models.I'm just a private user, the offer from local LPKF reseller is a lot of money.any help ?Regards,Bart , Netherlands

author: nctnico
author_rank: Super Contributor
timestamp: May 06, 2020, 10:52:16 am
content: Some advice: Before powering on a new board check the power supply. I think the root cause is in there. A shorted chip doesn't cause power converters to burn up; these have current limiting. Excess voltage from a power supply OTOH can do a lot of damage. I don't know which voltages come from the power supply but a good modification would be to add a TVS across the power supply connections to prevent future mishaps.

author: bartver
author_rank: Contributor
timestamp: May 06, 2020, 02:42:58 pm
content: Hello Nico,Thanks for taking the time to offer suggestions ! Just a bit of background what i already did :The E33 has an external brick 19V power supply, the motordriver part en the compute part are seperated on the board. (It's one big A4 size board that holds all)The Arm CPU and the FPGA are powered by a 3.3V buck converter, which is shorted out. (It was - don't no how to say that in english - hicking. Led just flashed every second.That is after i replaced two 1 ohm 2512 resistors that acted as a sort of fuse, the cpu part has two power circuits.I removed part of the 3v3 supply and used an external power supply for more control.The 1.5V parts, and a 3.3V LM117 are working too. There are also two 24 to 5 V AIMCO isolated dc-dc converters, generating -5 and +5, the +5V is blown, I exchanged it, and the new one died after 30seconds.When supplying power to the CPU/FPGA that draws over 1A at 1V already, and using a thermal camera i can see that only the fpga is heating up, can't see any traces or other components being affected.(it's a flir E4 - can see 0.1C differences) The FPGA heats up pretty quick - it must be the shortContemplating the route of taking of the fpga, didn't check yet if it has internal flash or not, i have no way to update it otherwise.Bart

author: IconicPCB
author_rank: Super Contributor
timestamp: May 06, 2020, 08:48:09 pm
content: A less expensive solution may be to throw out original electronics.I guess the machine uses stepper motors.Purchase/build stepper motor drivers.Get a PC runing LinuxCNC and use it to drive the motors.You may loose some of the features of original machine set up ...but then LinuxCNC offers many options.LinuxCNC is free. Itis a machine controller based on G code.

author: trevwhite
author_rank: Frequent Contributor
timestamp: May 07, 2020, 08:30:11 am
content: It probably is quite a bit of work to replace the electronics but there might be some solutions out there.I have built a CNC machine using the following board and it works great. Has all the stepper motor drivers on board and also limit switche inputs for homing. Has PWM outputs which might be required for the speed control on that machine? I do not know the current consumption of the steppers in your machine but if they do work, this board with Marlin firmware may actually work. There are cheaper boards out there but this is just a board that I have used and know works on cnc and also is sold by the company that make it so you get support as well.https://ultimachine.com/products/rambo-1-4