CTC printer Heated Bed will not heat up

[slippyr4]

What’s that “Bed temp” thing on the case?

[Suggy]

Don’t know if this is aimed at my machine but I guess it is

It’s so I can alter the bed temp on the fly.

ie I some time have a separate temp meter taped to the bed and if I get different readings from the display screen I can alter the temp without restarting the print. Control panel only lets you alter the temp on the hot end and not the bed.

Hope this make sence?

[Tony1170]

Hi Jon,

Sorry but you`re comments just gone straight over my head!!

Can you clarify? Further progress with CTC seems, they have agreed to send out a new HBP shows dogged persistence may pay off. Dont know if a new HBT will cure the problem but, I would still like to discover the culprit behind this fault whether that be something I am doing wrong or indeed a manufacturing problem in the hope that this could help anyone else who suffers the same in the future. That is if youre still agreeable? Don`t know when they would send out the new part or even at this point if I will actually receive it, only just received the email seconds ago.

Could the problem be within the capacitor on the HBP ? I am lead to believe that if that is faulty it could give erroneous reading from the thermistor.

If all else fails and even a new HBP wont fix the problem, I may if it is possible have to use a separate heat bed system completely independent of the motherboard. I would imagine this is possible as I have seen this:- MakerBot Replicator 2x Build Plate Heater KEENOVO Silicone Heating Pad 130W 24V | eBay? MakerBot Replicator 2x Build Plate Heater KEENOVO Silicone Heating Pad 130W 24V.

Only seems to have four wires though and I`m not sure as to how it would be wired I assume I would need a method of controlling the temperature and a way of monitoring via some sort of separate display. Now am I getting carried away with myself and just talking rubbish!

I think if I am right that the bed temp thing you may be talking about is just a normal home thermometer it was pictured just to show the ambient room temperature nothing else. It is not part of the original CTC printer or any addition.

[slippyr4]

What is the voltage between the 5V and GND pad on the HBP when plugged in?

(Ignore previous comment; mixed up with the photos)

[Tony1170]

Hi sorry for the delay in replying had to go out.

Just took measurement:

Meter set at 20v dc measured from 5v to ground on HBP this gave a reading of 4.9v I assume that`s about right! I imagine that the fault if there is one could be further down the line.

Dont know what the capacitors role in the circuit is?

Am I just jabbering junk please feel free to say so; just trying to use logic could be completely wrong!

[slippyr4]

The capacitor is just for decoupling, it’s not significant (unless it’s faulty, unlikely).

Unplug and measure the resistance between the 5V and the SIG pads, and also the resistance between GND and SIG. You’ll want your meter in the ~100K range.

[Tony1170]

Hi Jon,

My Meter has`nt a 100k range so took readings set at 200k

Then borrowed another meter so I will give two sets of readings one from each as I am not familiar with meter reading I have attached photos of both types of meter as well as settings used.

First meter Vici set in kilohm range Reads as follows: (This is More of an auto reading meter also has a auto range but I set it to kilohms hope thats right!)

5v to Signal = 4.694K

Signal to Ground yellow wire = 0.518K

Signal to Ground green wire = 0.511K

Readings from second meter set at 200K as follows:

5V to Signal = 4.7

Signal to ground yellow wire = 00.5

Signal to ground green wire = 00.5

Not sure but both meters seem to agree I think!!!

HBT Disconnected from machine when readings taken.

Hope these are correct settings

Ignore display on meters just notice settings if that makes sence.

[slippyr4]

There you are then. Your NTC is either knackered, or the wrong sort. It should be around 100-120 K ohms at room temperature, and its reading 0.5k.

[Tony1170]

Well thats a surprise! I purchased and fitted the new one when the HBP wouldnt work with the original as I had read and seen on you tube that the original should be replaced due to inaccuracy issues. Is it possible that BOTH original and replacement thermistors are faulty How unlucky is that!

I purchased the 100K NTC 3950 Thermistor from ebay (" Ideal for 3D printers ") obviously NOT!!!

I can`t thank you enough for the time and effort you have put into diagnosing this problem!

I will send for a new thermistor difficult to find a genuine supplier can you recommend?

I will keep you informed should I get a new part and fit. Hope our little adventure is also helpful to anyone else who ends up having a similar problem; GOOD to know there are people like yourself out there prepared to help people with little or no knowledge and wish to pursue new hobbies ect.

Thanks again.

PS. Curiosity killing me! So Ive cut off the thermistor and taken a reading straight from the component legs Ive taken a picture of the result ??? Am I wrong or is that near 100K?

[ThreePegasus]

Can you get the printer on at all? If so you can go to the general settings and do a factory reset on the printer it will reset all to defaults including the firmware. Also if its not working you can try and contact the seller you bought it off and get replacement parts as it should have a years warranty i got a new motherboard when my USB chip blew in mine for free.

[slippyr4]

Factory reset just wipes EEPROM, it won’t restore the original firmware.

[Tony1170]

Yes the printer operates all except the HBP have already tried what you have suggested and comments from Jon are correct!

CTC have agreed to send a new HBP when it will arrive not sure.

[Tony1170]

Hello sir,

Just for you to ponder Last night after removing the thermistor I re-took meter readings from the HBT this time without the thermistor fitted! So open at all four tabs both for old and new thermistor positions results are:-

5v to Signal = 4.964

Signal to ground yellow wire = 0.498

Signal to ground green wire = 0.497

I used probe clips on the meter this time as to not have any influence from my body, I noticed that at first the readings for:-

Signal to ground yellow and Signal to ground green took some time to settle as both at first produced fluctuating readings from the 0.550 range up to 0.950`s then back down again several times until finally settling at the figures above. Is that normal would have thought the readings would have been stable from the outset?

Sorry for imposing upon you feel free to drop this mystery anytime, I would totally understand.

Would I be right concluding it can only be one of three things:

1. Since the fault was apparent from the start its a hardware problem.

The HBP or the main board?

2. I`m a prat and have done something wrong! ( Although all I have done is print using a cold HBP and I know how to turn on and off the HBT within display settings.)

3. This is some kind of software problem caused by the sailfish 7.6 firmware I upgraded ( If this was the case why did the HBP not work with original firmware?) Is it worth trying to reinstall said software and have I used the correct firmware and selected the correct board? See info as displayed on LCD Information:

SAILFISH REPLICATOR1 (cannot see if any other characters are on this line or is it complete?)

Free SRAM 800 ( This line seems to flicker )

Thing 32084 r1220M

Firmware Version 7.6

One more change Ive noticed is that since upgrading firmeware the bed levelling procedure dosnt use the four or five positions it offered originally ; press menu to move to different locations and measure. Now the head just goes to the centre of the HBT and thats it! Then press M to exit. All other new menus and sub menu`s seem to be fine just not sure if this is relevant.

Thought I`d mention in case this pointed to possible firmeware issue.

[slippyr4]

It could be the capacitor is faulty and has some resistance, or it could be a faulty PCB. It’s a bit hard to diagnose via a forum. Your HBP is definitely faulty though, I don’t suspect that the mightyboard is.

The firmware has had nothing to do with it. Sailfish is much better than the stock firmware, don’t waste your time going back.

You are right that the sailfish levelling wizard is different. It’s better though. When it moved the carriage to the bed centre, it disables the X and Y steppers so you can move the carriage freely by hand. You can then move it so that the nozzle is directly over each of the screws, and adjust, in turn. Then you can check the middle. And repeat. It’s good.

[Tony1170]

This has been a great learning experience for me, all due to your teaching skills.

I had done some research about the sailfish firmware and everyone has the same opinion (It`s better).

I had noticed that moving the head was easier that`s presumably the X and Y stepper motors being disabled as you said.

Thought this might be the case and printed out a dial support for bed levelling a little while ago; much better way of doing levelling. Thanks to Thingyverse.

Seems we have reached an impasse as regards the cause of the mystery and with as you say the difficulties of trying to diagnose via the internet not having the actual components in front of one is a challenge to be sure.

I will as promised post the outcome of fitting the replacement HBP when it arrives. rather than leaving people wondering whether the problem was ever finally resolved.

I have learnt a good deal from yourself and thank you again.

Hope I may assist others in the future when I become more familiar with this hobby.

I hoped to apply 3d printing to my other hobby radio controlled aircraft although getting a bit long in the tooth now eyesight not as great as was, feel a bit of a fool when the plane your flying ends up actually being a SEAGULL!!!

[slippyr4]

Ha, snap, I fly R/C too.

Hope the new HBP fixes it for you.

[Tony1170]

Well whats the chances of that! Like minds on the web never thought that would happen in a million years.

Just venturing into quad copters.

I like have ago at all different crafts not that I`m great at any.

[Suggy]

Just a thought. A location may have been helpful. If you where near me you could have tryed my spair

[Tony1170]

Hi Ian,

Thats very kind! Im in knowsley, Near Liverpool.

[Suggy]

A tad too far I’m in Wakefield, near Leeds