CTC printer Heated Bed will not heat up

Tony1170 · 2017-02-26T17:18:52.000Z

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 · 2017-02-26T17:55:03.000Z

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 · 2017-02-26T20:34:12.000Z

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.

vici_meter_-_copy.jpg717×1275 736 KB

meter_2.jpg928×1650 1.12 MB

slippyr4 · 2017-02-26T21:31:39.000Z

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 · 2017-02-26T23:03:29.000Z

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?

thermistor_check.jpg717×1275 678 KB

ThreePegasus · 2017-02-27T15:24:37.000Z

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 · 2017-02-27T15:26:47.000Z

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

Tony1170 · 2017-02-27T16:36:01.000Z

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 · 2017-02-27T17:19:41.000Z

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 · 2017-02-27T18:07:00.000Z

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 · 2017-02-27T20:19:04.000Z

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 · 2017-02-27T20:55:03.000Z

Ha, snap, I fly R/C too.

Hope the new HBP fixes it for you.

Tony1170 · 2017-02-27T21:05:27.000Z

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 · 2017-02-28T08:26:58.000Z

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

Tony1170 · 2017-02-28T10:19:25.000Z

Hi Ian,

Thats very kind! Im in knowsley, Near Liverpool.

Suggy · 2017-02-28T15:37:38.000Z

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

Tony1170 · 2017-02-28T15:43:09.000Z

Very generous offer anyway. Thank you.

Tony1170 · 2017-03-07T00:08:27.000Z

Just a follow up on the problem I was having with the HBP not heating up and giving false temperature readings.

As promised I have found the **culprit to my woes** in the form of a capacitor on said HBP after de-soldering and cleaning the pads on which it sat ,I measured the capacitance with a meter and got a reading of 1007uf ( Now Im no electronics wizz and I have only picked up tips from people kind enough to help me ) So don`t take the capacitor value as accurate if possible measure it yourself or get someone in the know to help.

Having said that I re-soldered the offending item back onto the HBP and hey presto it worked! ( well for a good few hours anyway).

Whilst it was working I found it to be very accurate temperature wise. I checked this with a laser temperature gun.

It was very worthwhile changing the thermistor for the 100K NTC.

I think the problem was a dry joint together with a faulty capacitor as it has since died.

I have now received a new replacement HBP from CTC so, it pays to be tenacious, only got one by going back through ebay; CTC won`t reply to you if you try to contact them directly.

This new HBP also needs the thermistor changing as the temperature is way off.

I will repair the old HBP with a replacement capacitor and I`ll then have a spare.

Hope this information is useful to others who may experience this same problem; simple fix when you know what the problem could be.

Suggy · 2017-03-07T00:27:00.000Z

Glad to here you have got it sorted. Forgot to mention when I upgraded to my home build HBP I also upgraded the power supply. I’m in the middle of building a XL ctc but running on Arduino and ramps 1.4 (still struggling with firmware (not been well back trouble put me in hospital for 2 week)). My work shop is in the loft with ladders as access so it’s been put on hold until I’m well enough. Pic so far.

20161213_211943.jpg5312×2988 3.43 MB

Tony1170 · 2017-03-07T12:23:18.000Z

Hello Sir,

Thanks for your comment. That looks a great machine have you cut the cabinet yourself; acrylic is it?

Just trying some ABS having problems sticking to bed, Im using a glass bed with glue sticks think my problem is the new heat bed not reaching 110C. I have not yet fitted the new thermistor and the original supplied on the board just dosnt do the job.

Still practising. Sorry to hear you are unwell I know what back trouble is like suffer from it myself not long had an epidural ( Don`t recommend as it did me no good at all) Hope you recover soon.