iOptron ZEQ25 Polar Scope LED Illuminator replacement

There have been a few issues with my iOptron ZEQ25 which have required some attention to. The good thing is that it is a mount which is rather easy to tune up – I must have taken it apart and reassembled it at least 10 times now. But one of the things which I had not had the time to sort out until now was the polar scope light – this was no longer functional following the upgrade to the ADM Losmandy/Vixen Dual Mount clamp.

Now I had contacted iOptron about this issue, and they were very prompt with their reply, even on a weekend. Unfortunately, the advice was that it would cost $30 to replace the LED illuminator including cable, or $15 without the cable, plus $15 for international delivery. And if I factor in the VAT and processing costs in UK, that would make this cost over £30 – and I wasn’t going to pay that much.

They did give good advice: check the RA board to see if anything was touching the mount and causing a short (especially the C6 capacitor) – they suggested adding electric tape to prevent a short, and not to overtighten the screws when putting the board back. Something worth knowing for those likely to be taking the mount apart.

Anyway, I decided to go the DIY route using the original casing of the LED illuminator. First off was to remove the cover protecting the LED illuminator off the mount – this just pulls off.

Polar scope illuminator module mounted on iOptron ZEQ25
Polar scope illuminator module mounted on iOptron ZEQ25

You are then left with the LED illuminator, which needs to be unscrewed off the mount.

Cover removed
Cover removed
LED illuminator removed from mount
LED illuminator removed from mount

Next, this LED illuminator casing can be taken apart to show the various parts. It is amazing that something that small would cost that much.

LED illuminator
LED illuminator

The base can be unscrewed off to reveal the LED.

LED illuminator rear connector
LED illuminator rear connector
Parts of LED illuminator
Parts of LED illuminator

To source the various parts, I had taken a trip down to Maplin which sells all sorts of DIY stuff. I ended up buying 2 x 5mm 2.5V 4000mCd red LEDs, as well as 2 x 5mm 2.5V super bright red LEDs (the clear ones). Sadly the super bright LEDs burnt up once they were connected, so I would advise to avoid these. But the 4000mCd LEDs worked a treat. I decided to just use insulating tape to secure the LED to the battery cables, so it would be easier to replace a blown LED bulb.

2.5V 5mm Red LEDs - the clear ones are the super bright LEDs
2.5V 5mm Red LEDs – the clear ones are the super bright LEDs

For the power, I bought a clip on connector and a 2 x AA battery holder – I intend to use 2 rechargeable AA batteries which will have a voltage together of about 2.5V.

Clip on connector for battery holder
Clip on connector for battery holder
2x AA battery holder
2x AA battery holder
Mounted together
Mounted together

Now with everything connected together, the LED does light up very well.

Red LED connected to the battery holder
Red LED connected to the battery holder

Now I have a fully functional polar scope once more. I spent just over £7.00 to make this, but would have cost £2.88 less if I did not buy the super bright LEDs which blew up when connected. But I have saved myself a good amount of money and will be able to replace the LED in future should it stop functioning.

Lights up the polar scope
Lights up the polar scope
Battery holder is velcroed to the tripod
Battery holder is velcroed to the tripod

I did find that I needed to dampen the light of the LED as it was too bright otherwise to see Polaris through the polar scope. Now that I have fixed this, it works perfectly as before. Which is great.

Despite all the issues I’ve had with the iOptron ZEQ25, I still have to say that I really like this mount – it is so easy to set up, to tune up for best performance, has a great polar scope which works as normal again now with my DIY LED illuminator, and guides so well, and does not cost alot.

Boon