thanks both of you kind folks for the information. Knowing the thermistor is a 10Kohm helps heaps. I can now experiment and see what works best. I'm a retired technician fixing TV's VCR's DVD's etc. and have lots of spare parts. I have both brand new NTC and PTC thermistors of various values so I'm confident to come up with something that works. Sure, I could simply buy one from one of those online stores you kindly linked, Korth, but where's the fun in that? LOL.
BTW i'll post my finding once I evaluate what type of thermistor works on these mobos… they should all use the same type I'd say.
Meanwhile, if anyone reading this has purchased a temperature sensor and has some basic knowhow on how to use a multimeter, one could simply read the resistance of the sensor by probing the two wired plug that plugs into the external temperature sensor header on the mobo [while it is not connected to the mobo, of course], and read the resister value at room temperature or about 20C. Then hold the thermistor end in one hand to warm it up and take another reading. If it reads a high value when it has warmed up then it's a PTC thermistor, if it's a lower value then it's a NTC... any tech-head takers out there :cool: ?
update: I checked the online store [
https://www.adafruit.com/product/372] and it clearly states 10K "NTC". QUESTION answered and problem solved. Thanks again Korth for the links and Namoi too