New A5 Reboots when preheating bed for leveling

Milk_And_Ammo

Hey all...
Just received my A5 and it was packaged nicely... took more time unwrapping than assembling..
FYI: new A5 actually has a removable black diamond glass plate... its no long perm attached...

Watching videos and preparing myself for the machine... we were told to warm up the bed prior to leveling...  nozzle warms up great and fast...
I set nozzle to 0c and went to up the heat bed... if I turn up heat past room temp... I see a red light reflection from underneath the machine... then... poof... machine turns off and reboots...

I then placed my hand on the bed... the temp rises a degree or two on the screen...  thermistor appears to work...  plugged in my MacBook and ran print run...  after downloading the drivers and rebooting my mac... printrun found the usb connection...  set proper baud rate and the A5 performed everything I asked through print run...  looking at log when upping bed heat...  Im not noticing errors... unless they aren't blatant... 

I took apart machine today and checked for damaged wires... A5 no longer uses the wire track...  I cut the zip ties and looked at wires before securing and assembling again...  WHAT AM I MISSING??

Samuel Pinches

It sounds like you have received the latest revision of the printer. JGAurora replaced the high quality meanwell power supply in recent machines, with a similar power supply of the same power rating, from an unknown manufacturer. My suspicion is that this new power supply is not of sufficient quality.

There is also the possibility that there is a fault with the motherboard. You could unplug the bed heater, and the nozzle heater, and put the nozzle heater into the bed heater socket. (Leave the bed heater unplugged, the nozzle heater socket is not rated for the high bed current). Then, swap over the two themistors TH1 and TB, so effectively when you tell the printer to heat the bed up, it is heating the lower load of the nozzle instead.

If that still causes the printer to restart, then it would likely be that you need a new motherboard. If it doesn’t, then it is most likely an issue with the power supply instead. I’ve linked the high quality meanwell power supply on the wiki spare parts page.

Hope this helps you troubleshoot. It’s not really fair for a brand new product, but this is part of what happens when JGAurora cuts corners unfortunately.

Samuel Pinches

I would also be interested to know if the bed really is removable, if you take off those clips. My current understanding is that they still used the adhesive as well.

Samuel Pinches

You could also inspect the soldering of the heated bed connector, or see if there is any damage on the underside of the heating PCB tracks. If you have a multimeter you could measure the resistance of the heated bed over the power cables too, and check that it is not too low.

Milk_And_Ammo

I actually unclipped and totally removed the glass... had the glass set aside while I took the machine apart.  Its very true lol

I have the machine running now.  While dissecting it... I pushed in wires and unplugged and plugged in things...  

Bed seems awfully warped... even had the calipers out...  I did the firmware update and mesh bed leveled... 

Used the A5 profile from Github (which is same as one you reference, coincidentally) ... sliced a “Benchy” to flash drive, inserted it into A5 and ...  nada...  think it was my flash drive...  I just formatted the flash drive for mac journaled as I hacked my way into installing High Sierra on my unsupported mac...
I tried to FAT flash it back... A5 won't recognize any files on my flash drive... plugged in the drive that came with A5...  not sure what the sample object is...  but the code showed a square bed with a tube up from it...  sliced “Benchy” to the included flash drive from A5 box...  A5 recognizes that drive. good...  but still won't recognize my reformatted larger thumb drive...  ugh..

Anyways...  “Benchy” starts off... crappy...  lays zero lines down... almost like its not extruding while it circles around...
stopped it
Tried JG’s sample file.  It started up and actually laid down material. BUT, only 3 layers up, the base warped from right to left... had to cancel. Presumably due to first layer settings off. It’s a learning process, I know. 

Milk_And_Ammo

I’ll post pictures of the removed bed glass tomorrow for ya, Pinches

Samuel Pinches

Thanks - good to know.

Just remember that you only need 3 points to constrain a plane... with 4 screws its easy to cause a warp, as the design is overconstrained.

Milk_And_Ammo

holy sh!+, Pinches. How’d you even read my previous posts...  Edited them just now. Easier reading, I hope. 

I wanted to thank you for this site and your time helping us. Solid man you are. 

Samuel Pinches

Cheers mate. Hope you get it sorted. 👍

Samuel Pinches

FYI Fat32 has a limit of 32GB, so if you use larger than that you'll probably run into issues.

Milk_And_Ammo

As for the warped bed. I reset the bed screws 5-6 times and got them within a hundred thou before proceeding with bed leveling. back left, back right and front right were smack on... but front left would be a mm or 1.5mm too far away from the hot end.  i’d give in and adjust that... then the back left would be pushing on the bed... vicious circle. I can almost see by eye the left rail slightly bent downwards just after the opening for the bed heating wires/connector. 
Unsure if that can even be replaced or if it would come with a bed swap

Samuel Pinches

I haven't looked into the bed mechanics / assembly much myself... if things are bent I know it gets frustrating quick trying to compensate for that with levelling... a straight edge and calipers are your friend to check the squareness of everything. The bed supporting frame is a little too weak by design in my opinion, but you can probably bend it back by hand if you need to make corrections.