CTC clone help needed

[Don]

Hi,
I'm new to 3D printing and bought a CTC dual clone off eBay and am having trouble(s). The seller is useless and will not help so I'm on my own.

It worked very good for two days.
Then the #2 (left) extruder quit. #1 (right) extruder still working.
Then ReplicatorG gCode said it looked for 2 tools but could find only 1. I checked my drivers and have "replicator dual" selected.
Next I started having temperature problems and received "over temp" warning.
Now... every time I start the printer it goes into "high temp, please shut down". and will not re-set.
I disconnected the thermocouple wires from the "hot end" and ohmed them out for continuity, they are not "open". While disconnected machine still gave over temp warning.

I do know a little about electronics (model railroader) and have meters and such but know nothing about 3D machines.

I need help and advice on what to look for next and where to purchase replacement parts.

Thanks,
Don

[Don]

A little follow up....
I got brave and unplugged all the connections from the mother board except the "power in" and the LCD display. It still beeped and said "over heated".
I have to think it's a bad mother board...but where to find one ??
Don

[Mjolinor]

It probably will say that without a temperature sensor in there.

[curious aardvark]

well replug all the things back on the board and see if it's started working.
9 times out of 10 these things are a loose connection.

[Don]

I found out that the temp sensors are built into the motherboard.

[Don]

No luck on that "fix" tried it all, no luck.
I did find a USA based company that will help. I described the problem and was told it is a bad motherboard. I ordered a new one.

[Mjolinor]

The temperature sensors cannot be "built onto the motherboard". It is not possible to measure the head and bed temperatures with a sensor on the motherboard.

You need to address this methodically not go spending money on new bits without finding what is wrong.

Post a picture of the motherboard so we can work out what type it is.

[Don]

OK, here's the pictures.
DSCN0740.jpgDSCN0741.jpg Don

[Don]

It's hard to see in the pictures but in the top left corner is where the temperature sensor wires connect. These wires are attached to the hot end with a screw, each attachment screw has two wires that run down and attach to the board. I have ohmed them out and they are not "open".
I have been told that this is the "old" way, the newer ones have a little sensor that is inserted/attached to the hot end. My unit is defiantly the "old" system.
On the bottom row of green plugs, just above the third plug a small red LED lights up continually. The word "overheat" is printed under it and stays on even with all the plug in connectors removed from the board.

[Mjolinor]

OK so it looks to me like a Mightyboard or a copy of it. The head temperature sensors are thermocouples, you can clearly see the amplifiers at the top left of your picture. In this case you need to measure the voltage they are putting out on their own without being connected to anything.

The full schematics are available so you can easily check what the problem with your board is. I am sure the problem will have been seen before so Google will find a solution I am sure.