Attention ZWO Cooled camera users

[Dr_Ju_ju]

Just a quick cautionary tale, for those users of the ZWO Cooled cameras. In particular, I'm referring to my, now aging?, ASI1600MM cooled camera, but I see the design appears to be common with the other models. Granted my camera mainly stays outside, rigged into the OTA etc., & covered with a waterproof cover when not in use, but even 'dome' users' devices, have to be open to the elements...

Recently I've been having some issues with the camera cooling being intermittent, i.e. not getting down to the set temperature. And, as usual, at this time of year, I give everything a 'spring clean', dry-out the desiccant tablets etc. so brought it in-doors.

First impression was apart from aging\tarnishing of the cheap chrome fan cover, nothing appeared amiss. I went on to remove the cover\fan assembly, and that's when I discovered the main problem. The fans' positive connection had corroded off, and with the fan not working'ish, some eight legged friends had tried to set up home, within the heatsink blades.

The fan itself is a 40mm Sunon DC fan, that I would normally expect to find on 3D printers\open frame power supplies etc., not what I would expect to see on a device intended for outside usage, but that is another argument. At some point I'll probably replace it with a Noctua fan, i.e. https://www.ebay.co.uk/itm/Noctua-NF-A4x10-FLX-40mm-x-10mm-Low-Noise-Premium-PC-Case-Fan-4500-RPM-17-9-dBA/122551437306?hash=item1c88a287fa:g:uocAAOSwaAlccBz7&frcectupt=true

After re-soldering the connections & re-assembling the camera, giving the fan cover a couple of sprays of Hammerite Silver, all appears to be working as expected again.

 

 

[Carbon Brush]

Having seen lots of cost cutting and basic design/construction errors in lots of astronomy kit, your comment comes as no surprise.
I won't rant about grotty DC plugs, intolerance to supply voltage changes, EQ latitude bolts made from cheese, etc, etc.?

If I may make a couple of suggestions to help with preventing corrosion from recurring?

The flux (cored in solder) leaves residues. Depending on the type of flux these can be corrosive, just messy, or almost invisible.
Of course the flux/solder used in manufacture is beyond our control.

For home use we tend to have one type of solder. Two at most. Plumbing and electrical.
At work we have different solder 'recipes' and different fluxes to suit various applications.

It is best to assume that solder is going to leave a corrosive flux residue that will undo your efforts in the middle of a session.

To prevent this, remove the residue from the joints afterwards using isopropanol on a cotton bud.
Having got a clean joint, heatshrink sleeve if possible. Otherwise apply a laquer coating.
A proper conformal coating for PCB use is best. But expensive when you only want a little bit.
Just pinch a bit of clear (or coloured) nail polish from the missus. Or use model aeroplane paint.
Or use a non corrosive silicone sealant over the joint. That has the benefit of providing mechanical support for the wire.

By keeping oxygen and moisture off the joint, it has the best chance of living longer than the rest of the equipment.

Hope this helps, David.

[Dr_Ju_ju]

I fully agree, as I'm in the lucky position of having multiple types of solder, with & without fluxes, and have been building electronic systems for internal & external usage over many years, and so yes I lacquered the connections, post re-soldering.

But then again how far do we need to take it, as in re-work ASI\ZWO, as the main PCB is mm away, with no protective layer being applied to the solder side.....

The modern way, is to build in obsolescence, to ensure that products have a limited lifespan, so we'll come back for more, else manufacturers would go broke, after we have bought the everlasting goods.....