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Post: Blog2_Post
  • Writer's pictureMichelle Law

Lessons from a cracked 780G pump

I woke up one Saturday morning a few weeks ago and noticed a long crack down the side of my Medtronic 780G pump.

There were a few unexpected twists and turns in what followed so this post is a heads up for Medtronic 780G users about what to expect if it happens to them.

There's quite a lot to think about:

  1. Is this crack a big deal?

  2. Will I get a new pump?

  3. How do I report it?

  4. Setting up the new pump

  5. Pairing the Guardian 4 sensor

  6. Waiting for SmartGuard to warm up

  7. The main things to remember if it happens again

Is this crack a big deal?

So here it is, a long crack down the side of the battery compartment.

The first thing I did when I noticed was to ask on Twitter. I wasn't sure if it was a "wear and tear" thing or a "you need a new one" thing.

Twitter folks said I needed a new one.

Some people replied and said they'd also had cracks in the same place on their pumps. Apparently it can happen if you overtighten the battery cap. I don't think I did that but it was good to know. Pumps get knocked around a bit in every day life so it's hard to know how it happened.

How you report it

I needed to contact Medtronic.

Then I hit the first hurdle.

The only way you can report a damaged insulin pump to Medtronic is on the phone.

You can't report it any other way. I tried messaging the company on Twitter, looked at options on the Medtronic e-shop, the We Care site and the Medtronic Penny app. No joy.

I was lucky as my pump was still working despite the crack but I had to wait until Monday to get through to Product Support.

Will I get a new pump?

Once I got through it was efficient, friendly and easy. My pump is still under warranty and the Product Support person said straight away that they'd send me a replacement, but it would take a couple of days. They also arranged for a courier to collect my damaged pump the following week to give me some time to change everything over.

The new pump arrived 48 hours later.

Entering settings into the new pump

It took a bit of time to get a new pump set up, but as all my device settings are saved in my CareLink account it was very easy.

I just had to click to download the Device Settings Snapshot report and work methodically through each section to enter the settings into the new pump.

Then I had to pair the pump with all the other things it connects with. The Accu Chek Guide meter that has a wireless link to the pump for finger prick readings - easy. The Minimed Mobile app, my Carelink account - both easy as well.

So far so good. Until I tried...

Pairing the Guardian 4 sensor

But you can't pair your new pump to your Guardian 4 transmitter if you are currently wearing and using it.

You can only pair the transmitter when it is on charge. At this point I had a few days left on the sensor I was wearing and the transmitter was stuck under a layer of tape.

I wasn't sure what to do.

Do I take the sensor off early and waste it? (In hindsight it would have been good if a spare sensor came with the replacement pump in anticipation of this.)

Do I leave the sensor and my damaged pump on until the sensor expires, then switch to the new pump?

Do I use the new pump and leave the sensor connected to my old pump so I can at least still monitor my sugars until it expires?

By coincidence the decision was made for me as my sensor failed later that day.

I paired the transmitter with the pump while it was on charge and inserted a new sensor. It worked fine.

Waiting for SmartGuard to warm up

By this point I had my kit all set up and communicating with each other.

Now all I had to do is wait 48 hours for the SmartGuard algorithm to warm up.

This meant mostly manual diabetes for the next two days. I activated the "suspend on low" function which helped avoid hypos, but other that that my sugars were not pretty.

After 14 months of using a loop, I realised I am now rubbish at manual diabetes, and for these two days my time in range suffered.

I've become so used to the 780G doing its thing. I don't want to be looking at my sugars all the time and giving myself corrections. Rising sugars weren't prevented. Overnight readings were high. I woke up out of range. It was horrible.

Just a couple of days without SmartGuard confirmed to me that I never want to go back to doing diabetes manually ever again.

I'm back on normal service now, SmartGuard is working and my time in range is back to an average of 79%.

The main things to remember if it happens again

Now that I've been through this process I thought it would be helpful to share my tips if your 780G is faulty or damaged in the future:

  • You can only report it by phone

  • Call during office hours for quicker service if you can

  • Use Carelink to find your pump settings

  • Pair the sensor transmitter with the pump when it is charging

  • Wait 48 hours for SmartGuard to warm up again

As always, if anyone has any questions about using the Medtronic 780G in real life, just let me know and I will try my best to help.


John Moore
John Moore
Nov 27, 2023

I've had my 760G, then 770g and now 780g and the plastic cracks in different places. Unfortunately it is becasue MD used a poor choice for plastic in making the pump. This new plastic is very brittle and cracks easily when you lean up against something or drop it. the pump will "probably " work fine with a crack but the risk is that moisture will get into the crack from a shower or rain, or if you live in a place with high humidity. I am super active and am outdoors all the time, hiking paddling, kitesurfing...etc... and i've has 4 pumps go bad with critical errors, and every time.......yep there's a crack. To address other suggestions that it…

Michelle Law
Michelle Law
Feb 20
Replying to

Thanks for your comment, it seems quite a common issue.


Aug 25, 2023

Thanks for the posting. Just read article and comments. Have been having problems for a while. on checking pump mine is cracked down the back. New pump now on order (again the weekend problem) thanks again

Michelle Law
Michelle Law
Aug 28, 2023
Replying to

Good point - I think this is a personal preference thing though. I have got my low alert set pretty low now so I actually act. When it was too high before I used to ignore it so the alarms stopped having any effect.


Jul 11, 2023

I know the company states these cracks are from over tightening the battery cap. But anyone have any thoughts on if they cracks could actually be from the batteries expanding with heat? And might have nothing to do with user-error??


Jun 09, 2023

Thank you - I found your post following spotting a crack in the casing of my pump this morning and following your advice am now awaiting delivery of a replacement 780g. Slightly miffed when asked if I used a silicon skin for my pump - "as these provide greater protection" - as I don't believe that the crack was caused by any kind of impact. However, did want to thank you for sharing your experience as I found this really helpful. Thanks, Roddy

Michelle Law
Michelle Law
Jun 13, 2023
Replying to

Glad it helped! I was asked the same question and I am pretty sure there was no impact with mine either.


Jun 09, 2023

Does anyone know what to do when smart guard has been warming up for more than 48 hours? Like you my bloods have been all over these last two and a quarter days

Michelle Law
Michelle Law
Jun 09, 2023
Replying to

It's never happened to me before - sounds like you might need to replace the sensor but maybe give Medtronic a call for advice.

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