Fingerprint/Password Smart Padlock (Waterproof, Type-C Charging)

After the customer received a shipment of 2,400 smart door locks and 600 smart handle locks, multiple devices failed to pair with the cloud platform during deployment. Symptoms include: devices remaining offline for extended periods, pairing requests being repeatedly rejected, and some devices being discoverable on the same LAN but unable to complete binding. The customer’s network environment uses corporate VPN plus multiple AP coverage. Lock firmware version is V1.2.0; Android and iOS apps are versions 3.4.1 and 3.4.2 respectively. The issue prevents the customer from performing bulk activations and affects installation progress at nearly 10 project sites. At least 90% online rate must be restored within a short time to meet delivery milestones.

1) Remote data collection: Shared a diagnostic toolkit with the customer via a secure channel and collected logs from 100 problematic devices, cloud access logs, DHCP allocation tables from routers and APs, VPN configurations, and corporate firewall policies. 2) Preliminary assessment: Based on logs, most devices complete mDNS/UDP discovery on the LAN but encounter TCP resets or timeouts when initiating TLS handshakes to the cloud; additionally, some devices repeatedly use locally cached old tokens causing the server to reject binding. 3) Remote debugging measures: a. Guided the customer to create a temporary test VLAN on a non-production segment and allow necessary ports on that VLAN (443/TCP, 5683/UDP for CoAP fallback), disable deep packet inspection by the corporate firewall for the target cloud domain, and apply VPN split tunneling to avoid NAT port rewriting. b. Deployed a debug firmware package V1.2.1-hotfix with detailed log levels to 200 devices via MDM bulk push and rolled out a TLS certificate rotation script, cleaning up expired local tokens on devices. c. Added a temporary whitelist policy on the cloud to allow devices to retry binding within a short window while logging retry sources to prevent mismatches. d. Conducted two remote video sessions with the customer's technical team (including screen sharing and on-site network device configuration), observed the pairing process in real time, and adjusted AP multicast/IGMP snooping parameters to ensure stable delivery of LAN discovery messages. 4) Verification and rollback plan: After confirming in the test VLAN that 480 of 500 devices completed pairing and remained stable online, replicate the network adjustments in production in batches; meanwhile prepare rollback firmware and configuration scripts in case of anomalies.

The customer’s batch of smart locks (total 1,200 sets) reported intermittent unlocking failures and poor fit between some lock bodies and door frames after installation. Fault symptoms: 1) fingerprint/password recognized successfully but the mechanical latch does not fully retract, preventing door opening; 2) some units stick under nighttime temperature differences; 3) some doors respond slowly to unlock after locking, with occasional error messages. The customer requires restoration to normal operation as soon as possible and assurance that similar issues will not occur in future mass shipments.

1) Remote preliminary diagnosis: Based on logs and on-site videos provided by the customer (the customer exported an STA file by connecting the device to our diagnostic tool), it was confirmed that the mechanical latch stroke is inconsistent with the lock body calibration, and some firmware and motor drive parameters are deviating. 2) Organize an on-site technical support team: Within 48 hours of receiving the task, dispatch a 4-person technical team carrying testing tools and spare parts (20 lock bodies, 50 latch assemblies, 10 drive motors) and on-site debugging tools to the customer's *** factory. 3) On-site inspection and batch processing: For 1,200 locks, perform sampling and repair in batches of 30 units per batch. For each batch: a) Measure mechanical installation dimensions, adjust the reserved latch clearance on the door frame and perform minimal milling corrections to the door leaf groove; b) Replace latch assemblies that show wear or exceed tolerance limits; c) Use our dedicated calibration tools to recalibrate motor drive parameters and limits and update firmware to a unified version; d) Perform offline self-checks of the identification module and clean sensors. 4) Establish a temporary on-site quality inspection line: Set up quality inspection stations at the customer's site to subject each repaired sample in each batch to 200 open/close cycle life tests and environmental temperature differential simulation tests (-10°C to 50°C), record the results, and release units marked as qualified. 5) Preventive measures and training: Provide two on-site training sessions for the customer's technical staff (installation standards, common fault troubleshooting, first-level repair procedures), and supply detailed installation and calibration SOPs, firmware upgrade packages, and remote diagnostic access methods. 6) Follow-up support: Establish a 3-month priority response channel (vehicle-carried spare parts support and weekly reports), and recommend that for subsequent shipments, 3% of each batch be provided as sample units for pre-shipment testing.