> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/integrations/third-party-readers/idemia-morpho/troubleshoot/idemia-readers-morpho-reader-failing-to-come-back-online-after-updating.md).

# IDEMIA reader does not come online after an update

Resolve IDEMIA Sigma reader failures after a mode change, database resynchronization, or firmware upgrade.

### Sigma reader will not come back online after a mode change or database resync (pre-2020 hardware)

In 2018, a Gallagher site had issues with certain Sigma readers connected to Gallagher hardware. If a Sigma reader (**Lite, Lite Plus or Multi**) had its mode changed or its database resynced, the reader rebooted but did **not come back online** in Command Centre. Power cycling the reader resolved it. IDEMIA, the manufacturer of Sigma readers, worked with Gallagher on a temporary fix until a Sigma hardware redesign.

* **Cause:** on pre-2020 hardware, the D0/D1 lines going into the reader stopped the reader power-cycling correctly.
* **Fix:** fit **2 inline isolating diodes (1N4007)** on the D0/D1 lines going to the Sigma reader, as pictured.

![Diode orientation (cathode/anode, current-flow direction) for the two inline D0/D1 isolating diodes, shown beside the C300665 HBUS 4-In 2-Out Door Module Wiegand terminal layout](https://328339335-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F6bM8WhlBE9BYizPWJaPN%2Fuploads%2Fgit-blob-2253e1c258cf6298bb1022570cb344e1541898de%2FSECHUB-int-idemia-02-diode-hbus-module.png?alt=media)

{% hint style="info" %}
Devices made after 2020 (serial numbers starting with `20xx`) are fixed in hardware.
{% endhint %}

To confirm D0/D1 wiring, see the related page [Wire IDEMIA readers over Wiegand](/knowledge-hub/products/integrations/third-party-readers/idemia-morpho/configure/idemia-readers-morpho-wiegand-wiring-videos.md), which also has the Morpho wiring videos.

### Reader will not come online after a firmware upgrade

The **firmware 11-10-2022 release** changed the configuration to **enforced secure**. New or upgraded readers will not come online and cannot connect via MBTB 4.6.12 or lower. Use the On-Demand Security procedure to recover an enforced-secure reader. [Enable On-Demand Security](/knowledge-hub/products/integrations/third-party-readers/idemia-morpho/configure/idemia-readers-morpho-how-to-enable-the-on-demand-security-state.md) explains how to put a Morpho reader into the On-demand Security state. More detail is on [IDEMIA reader cannot connect after the October 2022 firmware update](/knowledge-hub/products/integrations/third-party-readers/idemia-morpho/troubleshoot/idemia-morpho-firmware-11-10-2022-release-connection-issues.md).


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