You seem to be dealing with a malfunctioning electronic lock on a hotel room door. This might be due to a few different issues:

1. Battery issues: Electronic locks, typically supplied by batteries, require power. If the batteries are dying or dead, it could cause the lock to fail, even with a master key.
2. Mechanical problems: A physical issue with the lock mechanism might prevent it from unlocking.
3. Card issues: If the problem is only with the master key and not other keys, the lock may have stopped recognizing the master key due to a coding or programming error.

Here’s how you can troubleshoot:

1. Check the batteries: If the lock is battery-powered, try replacing the batteries and see if the issue resolves. This is often the simplest solution.
2. Check the key programming: The lock might not recognize the master key card due to a programming error. You could try to reprogram the key or the lock.
3. Inspect the card reader: It might be possible that the lock’s card reader is dirty or damaged. Try to clean it gently and check for visible damage.
4. Check Hotel lock PCB board: The printed Circuit Board (PCB) is essential to an electronic lock system. If there’s an issue with the PCB, it could cause the lock to malfunction. Here are a few steps you can follow to troubleshoot a PCB issue:
   • Visual Inspection: If you have access and are comfortable doing so, remove the cover and visually inspect the PCB. Look for signs of physical damage, burnt areas, loose components, or disconnected wires.
   • Check Connections: Ensure all the connections to the PCB are secure. A loose connection could cause the system to function incorrectly.
5. Reset the lock: If it has a reset function, try resetting it. This could clear any software glitches that may be causing the problem.
6. Contact the manufacturer or a professional locksmith: If the above steps don’t work, the lock is hard-wired, or you’re uncomfortable dealing with it, it might be time to get professional help. The lock manufacturer might be able to provide assistance over the phone or recommend a certified locksmith who can fix the issue.

Remember, it’s crucial to respect the privacy and security of your guests. Always follow your Hotel’s policies and procedures when dealing with room access and security issues.

For more hotel door lock problems and troubleshooting, please check this article: 11 Typical Hotel Door Lock Problems and Troubleshooting.