Thanks for great Customer Service !

[cropwell]

I take my hat off to Sam Courtney at Wanhao UK. My 4DS was very poorly and not printing well. Also it was resetting itself at random during a print.

Sam gave a lot of advice and also offered to send parts out, with the promise of a refund if they were returned as not needed (i.e. didn't solve the problem).

In the end I found two faults.
Muck in the card reader was possibly causing mis-reads and hence the resetting and freezing. This appears to be sorted with the air blower.
A faulty X motor cable (broken conductor - it is the only cable that flexes). I had a spare, so replaced it.

Now it is as good as new and is happily printing.

Cheers to Sam and Big Thank You!

Regards,

Rob

[cropwell]

Well, it looks as though I will be seeking further help from Wanhao UK as the machine will not get past the first couple of layers without resetting itself and stopping in its' tracks. It was going so well for a few weeks and then started playing up again. I have checked the connectors to the mainboard, so it is looking more like a mainboard fault, which will be a titser at £150 to replace.

Any ideas what I could test, bearing in mind that this fault only shows itself after a few minutes printing ?

[cropwell]

Fun and games time ?

[magicniner]

What's the board?
I replaced the cheap Chinese Arduino on my i3 clone with an official one, but only to keep the original firmware on the board shipped with the printer and run my modified Marlin compilation on a separate board.

[cropwell]

Hi Nick, TBH I don't know. It is an 'arduino', but it has all the bells and whistles needed on the board. I would rather just replace the board if I knew that was the fault. the chip is SMD and I don't want to mess with it. It has been working fine for 3 years and now there is just a lot of hassle with things going wrong. I will probably end up sending the board to Sam at WanhaoUK.

https://www.wanhaouk.com/collections...-4-motherboard

It is this one. You never know , it might be just a smidge of conductive shite between the reset pin and ground. My next move is to blow off any dust, but I am not hopeful of a result. I am not in a financial position to say sod it and buy a new machine like the i7.

Cheers,

Rob

PS there is an interesting bit about rafts on another forum

[magicniner]

PS there is an interesting bit about rafts on another forum

:D
Sadly it's going the same way as CNC Zone's own spinoff 3D printing forum went, too much BS from sellers, many of them from India and Admins that don't care too much ;-(

[Doddy]

Any ideas what I could test, bearing in mind that this fault only shows itself after a few minutes printing ?

It's a bugger.

So, it used to work, but is now intermittent? So something has changed.

Thoughts:

Dry-joint and thermal expansion causing the joint to break when the microcontroller starts to warm up. Reasonably possible - examine the SMD device under magnification; if you're handy with an iron (and have a reasonable good iron) then a splash of flux across the SMD pins and walk a ball of solder over the pins and clean-up with desolder wick/braid then clean the board with IPA etc.

or...

Another person had a problem with a failed crystal - a 16Mhz crystal costs pennies and is a 10 minute job to replace. It could be that it's failing under vibration of the printing.

or...

Power Supply failure?, might be worth scoping/triggering on the supply level dipping a bit. More unlikely than the above, and would need a scope to fault-find. Could be caused by a faulty stepper driver drawing too much current.

(that's a thought - can you drive each axis to see if any one is causing problems?)

Have a look at the caps around the switched-mode PSU - any sign of leakage or bulging - worth replacing (you could be getting spikes on the logic supply).

Other noise?, that micro is likely all configured for I/O with only the supply lines and reset lines likely to cause problems.

Actually, could you swap the drivers around?, see if the problem follows a driver?

You mention conductive crap... possible, and there's nothing wrong with a bit of compressed air (just don't poke it down the buzzer). But definitely worth an inspection under magnification.

AvE (youtube) has a plausible theory that thermal issues account for the majority of problems - have a poke around with a finger whilst the printer is running - anything getting hot?

Basically... lots of things to look at and definitely worth spending 30 minutes really going over the board.It's a low density board, quite workable, but much depends on your dedication to not spending money (I'd have a bloody good go at it before forking out £150)

[cropwell]

Thanks Doddy,

Before I get too involved, I have a couple of things to try. I always print using the SD card and a faulty reader could be the cause, so first I am going to try printing via the USB link. Also I will get a new card reader from Wanhao UK on a return basis. If no difference, it can go back. The same for the mainboard, but I may end up sending that to them to check out in another 4DS machine

Sticking a finger on components is difficult as they are all under the main deck and difficult to access when the machine is running.

I thought about the PSU glitching, it is a 24v SMPS unit, so I might just put some sort of voltage drop detector on it using my little scope, but that would be a pain and so is down the list.

Likely suspect is the card reader or the cable from the reader to the mainboard, I had trouble with it before as it got sh1t in it, so maybe the pins are messed up.

I haven't got £150 to shell out on an off chance anyway, so I would have to be damn sure first.

Cheers,

Rob

[Doddy]

Certainly worth trying the easier things first.

I think yours is similar to mine (a Qidi - looks externally very similar, I've had it apart in the past but can't remember the board) - certainly appreciate it's awkward to get to - but set it on a couple of blocks with the bottom off, you can poke a digit or two.

The SMPS - I was actually looking at the SM regulator on the corner of the card - that'll drop the 24V to 5V for the logic, that's the one I'd scope.

Ironically, my previous 3D printers (a RepRap) - it was the USB that was the weak point with ground loops/noise and the card reader more robust (until I tripped over the cable and yanked the micro USB connector off the main board and replaced with a BlueTooth UART, which solved all the problems).

[cropwell]

I have just ordered a new card reader. I will see if that sorts it out later in the week. Connecting via USB is a PITA, getting the coms driver working is not for the faint hearted.

I think I am going to forget the 3D printer for a day or two and cut some ali on my router. If that doesn't bugger me about !!!