ZWO ASI 071MC-c Pro heating by 20+ celcius above ambient rather than cooling?
After years of really solid performance from my four in use ZWO cameras - rather unsual behaviour from my ZWO 071MC-c Pro camera today; rather than cooling down its showing about 30 degrees above ambient!
I tried running it and my ZWO 1600MM-c side by side to take darks - in SGP couldn't get the 71MC-c Pro to 0 degrees (and its on a huge lab power supply). The ambient was 15 degrees - SGP reported it at 56 Celcius!!!
Then I tried APT - the first run it said it cooled to 0 in 5 mins, the second and it wouldn't get below 44 celcius. I tried TSX controlling the camera too - 44 was the lowest it could get to - about 20 degrees above ambient.
Is this the sign of faulty hardware or dying equipment? It is a few years old now and never given me a problem until today. It's all permanently mounted in my astro lab ánd connected by high quality USB3 cables tthrough a powered, high quality USB3 hub. I have had no gear or software changes for over 6 months and day in and day out this gear has all been rock solid until this afternoon.
The 1600MM-c behaves exactly as expected by all programs - but the 071MC-c seems to be heating rather than cooling. I tried switching off its power supplies - and checked them on a multi-meter and left it off and unplugged for 5 minutes - all brought no joy.
Thoughts / suggestions anyone? I did let TSX get to 80% power - still only got the 71MC-c Pro down to 44 celcius.
Yes - fan is spinning - everything looking normal - lab power supply is spot on 12V. So it all looks fine - just the driver reporting it's a toaster not a fridge.
Am powering everything down for a few hours to see if a hard on and off changes its behaviour...
I have no idea with the cameras but in most applications where I do know I'd hazard a guess there's thermal compound in the mix and it's gotten old and failed.
Again, I have absolutely NO IDEA if this is relevant to astronomy cameras.
Be worth looking into.
Keep in mind that this gear is designed to work on 12v battery systems and not 12v. You will find the camera specs allow a much higher voltage and that 12v is at the low end of the range. If any voltage drop in the cables, then the camera might be at too low a voltage. Try 13.5v and measure voltage at the camera.
Perhaps build a very short. Say 100mm cable with a socket at one end and a plug at the other. Scrape some insulation off the wires along the 100mm section but not opposite each other and attach some multimeter probes.
Measure the voltage when cooler is at max current.
Thoughts / suggestions anyone? I did let TSX get to 80% power - still only got the 71MC-c Pro down to 44 celcius.
G'Day,
with a problems like that, there are a few possibilities, try narrowing it down by changing the operating conditions for the camera and see if you get any change that could then lead you to a more specific diagnosis...
I'd try....
Changing the camera driver
Changing the PC or laptop you are using
Disconnect the camera from the hub and try it directly
Operate unit with 1 ultra short USB cable, perhaps the one supplied by ZWO
Try other imaging software, perhaps the ZWO supplied
Check heatsink temperature - if the sensor is 20-30°C above ambient then the otherside of the peltier cooler (the heatsink side) would be VERY HOT. maybe even use an non contact thermometer if you have or can borrow one, just to get a sense of whether the reported sensor temperature is ridiculous or plausible.
You checked the DC voltage from your power supply. Also check for any significant AC component on the output
If you have a lab power supply with an adjustable current limit, what was it set to, whilst experiencing these issues? On the rear of the camera ZWO specifies 12V @3A as required, but in other ZWO literature I have also seen 11 to 14V at 3 to 5A recommended. See ZWO details here....
In respect of the power supply, that of course doesn't explain why things may have been OK in the past, but not now, .... but who knows, something has changed.
May pull apart the beast just to see if there is any obivious internal fail - else see if ZWO say send it back to us for a repair.
I run a total of four ZWO cameras on three side by side or piggybacked Williams Optics refractors - my two cooled cameras are both powered by the same lab power supply - voltages measure with two multi meters at the power plugs ends that attach to the camera. They both use the supplied 2 metres ZWO USB 3 cables to connect to a high quality, powered USB3.1 hub that connects via a high quality 3 metre cable to the astrolab PC.
I tried swapping power supply cables betweem the cooled cameras - with either the 1600MM-c works fine but the 071MC-c Pro next to it heats up rather than cools.
As stated no software changes in 6 months bar a Windows 10 Service pack upgrade the other day. Cameras tested in TSX, APT and SGP - all show the same thing - which matches what the driver is reporting.
Just spoke to Bintel where I originally bought all my cameras - they said fill in a service form - and they will look at it and/or deal with ZWO - brilliant - that is my next course of action then - and buy a replacement whilst this is getting sorted!
A long shot, but if for some reason the polarity of the power lead is accidentally swapped, ie becomes negative tip, the Peltier will happily reverse and the cool side will become hot.
A long shot, but if for some reason the polarity of the power lead is accidentally swapped, ie becomes negative tip, the Peltier will happily reverse and the cool side will become hot.
Wonder if the camera would also emit the magic blue smoke?
There's no magic involved in the blue smoke. I have no idea why so many people refer to it as such.
I guess they haven't spent years replacing blown components and tracks on circuit boards.
I used to repair motherboards back in the early 90s (286/386/486) at a component level. Video equipment and TV's/radios prior to that.
Now I can't even see the components on motherboards.
I'm glad I can't see so well now, add in the missing mind that went with age, life is so much simpler.
I'd look at the Peltier plate. They can crack through thermal stress and can turn into a big resistor so your 3-5 amps "cooling" current turns into a few watts of heat.
If it turns out to be too expensive to repair through ZWO it might be worth checking the Peltier plate yourself.
It may be magic for people with plenty of money and people others don't take their stuff to to get it fixed, for me there's no magic involved, just incorrect polarity, current or voltage (or shorted alligator clips which I've had happen with temporary circuits).
I run a total of four ZWO cameras on three side by side or piggybacked Williams Optics refractors - my two cooled cameras are both powered by the same lab power supply - voltages measure with two multi meters at the power plugs ends that attach to the camera. They both use the supplied 2 metres ZWO USB 3 cables to connect to a high quality, powered USB3.1 hub that connects via a high quality 3 metre cable to the astrolab PC.
Just note when measuring voltage at your device such as a camera for people reading this and want to check something themselves. It needs to be done under load so in the case of the cooled camera, when it’s trying to cool at max power (or use a dummy load that draws a similar current).
You can’t test for voltage drop without doing that. It’s why I suggested a short test cable so you can access the wires to measure under load without accidentally shorting things out.
No load means little current so no voltage drop in cables, fuses, connectors etc that may have higher resistance than expected. So for the cable lengths and voltages involved, no load is likely to result in the same voltage as the power supply.
You might expect about 0.5v drop at the end but I’ve seen 1v or once 1.5v
At least a 12v battery which is really closer to 13v or over would help with poor or inadequate cabling.
Hi Greg, agreed - but the broad behaviour should be enough to point to the source of the problem.
Bintel has said bring it back to us - raised an out of warranty RMA and awaiting them to say drop it off.
ZWO Support got back and said absolutely don't throw it out - could be the fan or the main board - basically worth fixing - so will likely try and get it fixed and have it as a spare!
Camera is fine so far - so an RMA to Bintel this week is on the cards - bought a second hand identical camera from a kind forum member this morning - so I am not without! I did mis-count my ZWO stash - I have 6 ZWO cameras now - 71MC Pro x 2, 1600MM-c, 120MC, 120MS and 290MM mini.
I guess this make me an affinado of them. The 71MC Pro that has a hiccup is an upgrade to the 71MC-c I bought in 2016 - that was offered and accepted about a year later - so it has had a very good run!
