IDE Hard Drive Question

dwight dkelvey at
Fri Jun 26 08:25:51 CDT 2020

I'd measure the temperature sensor. It is most likely a typical thermistor but may be an RTD. Most RTD's are 100 ohm but there are some platinum on ceramic that are 1K ohms. Check it both directions with an ohm meter. It might be a solid state semiconductor type device. If a resistive device, it can likely be replaced by a resistor. If it is 10K thermistor or whatever just replace it with a fixed resistor.
Put it in the fridge for a few minutes to see if it is a negative or positive temperature coefficient. Once you know that it should be easy to use a value of resistor that would tell it that is was at a happy 20c.
You can likely leave the heater leads open.
The temperature sensor is the small black thing. I doubt it is a thermal switch but it might be. It is most likely to be around specific resistances of 10 ohms, 100, 1K or 10K.

From: cctalk <cctalk-bounces at> on behalf of jim stephens via cctalk <cctalk at>
Sent: Thursday, June 25, 2020 11:59 PM
To: cctech at <cctech at>
Subject: Re: IDE Hard Drive Question

On 6/25/2020 11:20 PM, Chuck Guzis via cctech wrote:
> On 6/25/20 4:12 PM, Jon Elson via cctech wrote:
>> On 06/25/2020 05:29 PM, W2HX via cctech wrote:
>>> Does ANYONE have any idea what these 4 wires are connected to and why?
>>> And anyone give any odds about whether these 4 wires will prevent this
>>> IDE-SD converter from working?
>> Temperature sensor and heater.  Undoubtedly for start-up in extreme cold
>> conditions.
> Certainly looks like that to me also.  Sits right atop the spindle motor.
> --Chuck
The drive spec I found for the Conner cfs540a (this drive) shows an
operating range of 5c to 55c.

The top of the range is useful for mil operations, but the 5c spec would
be bad if you ran the drive.

Full military just a casual google says is -55c, and extended industrial
is -40c on the bottom.  We
did -40 specs for some of our projects, but nothing mechanical. The are
at -40c to 60c for nonoperating,
so would be close to the low range if they could heat the spindle, and
let the drive heat itself up.

One issue might be that the sensor will heat up this dongle and allow
the thing to run, but there may
be a provision to spin the drive before it is expected to run.  A heat
up or warmup feature might
be performed besides what Jon suggested with the heater / sensor.

I suspect this thing has to heat up and be at temp before something in
the bios or otherwise allows
the drive to run.

The OP might look around and see if there are any of the heater strips
around as well, to allow
heating in the drive box as needed.

I may have one of these systems with some extra drives, and the good
news is they guy I bought them
from if mine are the same or of similar spec, is that he was putting
drives in the boxes from random
drive buys and they were easy to run.  He didn't recall the spindle
dongle on his drive pods though.

I'm waiting to hear for sure if the fellow I bought mine from remembers
the manufacturer.  The system
and an auxiliary box of similar size with more pods came in a deal I
couldn't pass up.  My box has
got a 486 motherboard and functional 10baseT card running in it.  I plan
to use one of the pods
to do one of these as solid state to save runtime on the physical disks.

spec I used at:

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