# Zymbit4 no blink
**URL:** https://community.zymbit.com/t/zymbit4-no-blink/1289
**Category:** ZYMKEY4
**Created:** [October 2, 2021, 4:34am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289 "2021-10-02T04:34:56Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [October 2, 2021, 4:34am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/1 "2021-10-02T04:34:56Z")
I have done the luks crypt and everything was working ok. Today I power up the Pi and it would not boot as the boot key was not accessible by the Pi. The Zymbit led is not blinking at all. Also, the tab has not been cut yet.
What could be wrong here. Is the Zymbit Key dead?
---
### Author:  [@Bob\_of\_Zymbit](https://community.zymbit.com/u/Bob_of_Zymbit)
#### Post date: [October 4, 2021, 2:18pm UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/2 "2021-10-04T14:18:50Z")
Hello Albert,
Can you tell me which PI, OS, and capture the last messages you see on the console? Is this a new setup or has it been working fine for a long time and then stopped working after the power up?
Bob
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### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [October 5, 2021, 12:38am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/3 "2021-10-05T00:38:14Z")
Hi,
It was working for fine for a few days with powering up and down. Then on the last time I powered it up, it would not boot and the Zymbit with no LED blink. The PI itself is working as I have reinstall the OS and Luks Crypt with a new Zymbit.
Putting the Zymbit on a new Pi also **did not** result in any blinking LED.
1. Raspberry Pi 3B+
2. Ubuntu 20.04 with all patches
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### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [October 27, 2021, 1:05am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/4 "2021-10-27T01:05:52Z")
Hi,
Is there any other information that is needed, please let me know? Thank you.
---
### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [November 25, 2021, 8:21am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/5 "2021-11-25T08:21:23Z")
Hi,
I have a another brand new Zymbit that is dead again. No blinking LED and the Raspberry Pi 3B+ does not boot. The Zymbit is in production mode with battery install.
1. Prepare the Zymbit
2. Encrypt the Zymbit for Secure Boot.
3. Shutdown
4. Boot up PI again next day (Zymbit is dead).
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### Author:  [@Bob\_of\_Zymbit](https://community.zymbit.com/u/Bob_of_Zymbit)
#### Post date: [November 28, 2021, 6:49pm UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/6 "2021-11-28T18:49:12Z")
Hello Albert, Most likely ubuntu has done an upgrade and tried to build a new initramfs. You should turn off the unattended-upgrades once you have encrypted your root partition.
```auto
systemctl stop unattended-upgrades
systemctl disable unattended-upgrades
```
---
### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [November 29, 2021, 10:09am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/7 "2021-11-29T10:09:45Z")
The auto update has been stopped just after the first boot before the Zymbit was installed. Now I have 2 Zymbit that does not blink even if I install in on a new PI. Is there any to check the status of the Zymbit or revive it? I am 100% sure that it was never set to production mode.
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### Author:  [@nareshn2003](https://community.zymbit.com/u/nareshn2003)
#### Post date: [December 2, 2021, 5:27am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/8 "2021-12-02T05:27:45Z")
Hi
Same issue with me. One device dead no blink after boot complete. It rapidly boots when power up but as Zymkey service start Led Blinking gone.
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### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [December 2, 2021, 10:13am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/9 "2021-12-02T10:13:18Z")
I have tried to probe the 12C, nothing, non of the test sample code runs. I know the Pi is working as I put in a new Zymbit and the sample code works. So it look from the outside. like it has execute the kill switch. The problem is that I have not activate any of the perimeter sensing code and the tab is still intact.
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### Author:  [@nareshn2003](https://community.zymbit.com/u/nareshn2003)
#### Post date: [December 2, 2021, 3:07pm UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/10 "2021-12-02T15:07:31Z")
Same here… New device worked but old device with tab intact led blink only boot time then nothing. May be device is bricked.
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### Author:  [@Albert](https://community.zymbit.com/u/Albert)
#### Post date: [December 3, 2021, 12:35am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/11 "2021-12-03T00:35:18Z")
At least you unit blinked at boot time. I have two units that does not blink at all. Even plugging it in on a new PI.
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### Author:  [@nareshn2003](https://community.zymbit.com/u/nareshn2003)
#### Post date: [December 3, 2021, 5:00am UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/12 "2021-12-03T05:00:53Z")
I had impression this device is good for industrial use but not good. Even no support from zymbit on my last two queries.
I also have few queries where device get bricked after 2-3 month usage posted here.
> [@Zemkey Lost after few month of usage?](https://community.zymbit.com/t/zemkey-lost-after-few-month-of-usage/1317):
>
> Hi We had deployed more than 15 devices using Zymkey and Raspian latest operating system. But almost 8-10 device has been stopped working after few month usage, no idea why ? What we did to device. Device is enclosed in box with perimeter detection using switch . Device enclosure is permeant cannot be open even by us because it is sealed with Epoxy potting resin (Black Solid). Device is in overlay fs mode in rpi so that partition doesnot get corrupt due to power cut. How to know what causes…
No Reply from support team yet.
I am thinking to move to another options. i.e. Encrypt partition and decrypt automatically using password from cloud server.
> **[Unlock encrypted disks on Linux automatically](https://opensource.com/article/20/11/nbde-linux)**
>
> From a security viewpoint, it's important to encrypt your sensitive data to protect it from prying eyes and hackers.
---
### Author:  [@Bob\_of\_Zymbit](https://community.zymbit.com/u/Bob_of_Zymbit)
#### Post date: [December 3, 2021, 5:54pm UTC](https://community.zymbit.com/t/zymbit4-no-blink/1289/13 "2021-12-03T17:54:37Z")
@Albert@nareshn2003 I’d like to address your two issues separately. You seem to have two different situations but the end result is a ZYMKEY that is not blinking. One thing as always is to make sure you have a good power source, not a phone charger. The ZYMKEY will put itself in sleep mode if it detects inadequate power so we need to eliminate that first. I will contact each of you directly via support to get more information on the history of your particular ZYMKEYs.
Bob