How to Check an Unknown LAN Point Before Reusing It – FNIRSI LPM-10A Malaysia
How to Check an Unknown LAN Point Before Reusing It – FNIRSI LPM-10A Malaysia
You move into an existing office and find several RJ45 wall outlets.
Some have labels.
Some have no labels.
Nobody knows where the cables go.
Can you simply connect a computer and start using them?
It is better to check the network point first.
An unknown LAN point may be connected to an old patch panel, unused cable, active switch, PoE switch or completely different network segment.
For IT technicians, contractors and building maintenance teams in Malaysia, the FNIRSI LPM-10A Network Cable Tester can help identify and evaluate an existing LAN point before it is reused.
FNIRSI LPM-10A Feature Summary
| Function | Typical Use |
|---|---|
| Cable Tracing | Find where an unknown LAN cable goes |
| Wire Map Testing | Check RJ45 wiring and connection faults |
| Cable Length Measurement | Check approximate installed cable length |
| PoE Detection | Check PoE information during troubleshooting |
| Port Flash | Help identify the corresponding switch port |
| Network Speed Test | Assist with basic network connection checking |
| NCV Detection | Supplementary non-contact voltage checking |
| Colour Display | Easier viewing during field work |
For an unknown LAN point, the main objective is:
Identify → Test → Confirm → Reuse
Why Existing LAN Points Can Be Difficult
Older offices may have been modified many times.
Over the years:
Tenants change
Desks move
Partitions change
Switches are replaced
CCTV systems are added
Wi-Fi access points are installed
Network cabinets are reorganised
The wall outlet may still exist even though the original network layout has changed completely.
Never assume an old RJ45 outlet is ready for immediate use.
Step 1: Inspect the LAN Outlet
Start with a physical inspection.
Look for:
RJ45 damage
Loose faceplate
Dust
Corrosion
Broken contacts
Old handwritten labels
Signs of renovation
If the outlet has been unused for years, inspect it carefully before troubleshooting deeper into the network.
Step 2: Don't Trust the Label Completely
Suppose the outlet says:
LAN-12
That label is useful.
But does LAN-12 still correspond to the same patch-panel position?
Maybe.
Maybe not.
The cable may have been moved during previous renovation or maintenance.
Therefore:
Old label = clue
Testing = confirmation
Step 3: Check the Cable Wiring
Use the FNIRSI LPM-10A wire-map testing function to investigate the Ethernet connection.
Before trying to use the outlet for a computer, CCTV camera or access point, check whether the installed wiring appears normal.
Possible problems include:
Open conductor
Incorrect termination
Loose connection
Damaged RJ45 termination
Patch-panel problem
An outlet can look perfect externally while the cable behind it has a problem.
Step 4: Trace Where the Cable Goes
This is one of the most important tests for an unknown network point.
Use the cable tracing function to help locate the corresponding cable at the network cabinet or cable bundle.
You are trying to answer:
“Where does this wall outlet actually go?”
Once the cable is identified, you can investigate its connection at the other end.
Step 5: Check the Patch Panel
After identifying the cable, inspect the corresponding patch-panel connection if the installation uses one.
Look for:
Loose termination
Missing patch cable
Incorrect label
Damaged port
Old disconnected cable
Sometimes the wall outlet itself is perfectly good.
The only problem is that nobody connected its patch-panel port to the network switch.
Step 6: Identify the Switch Port
If the LAN point is already connected to a switch, determine which switch port it is using.
The FNIRSI LPM-10A port flash function can assist with switch-port identification.
This becomes useful when the cabinet contains:
24-port switches
48-port switches
Multiple switches
Poorly labelled patch cables
Knowing the correct switch port also makes future troubleshooting easier.
Step 7: Check Whether PoE Is Present
This is especially relevant if the unknown point was previously used for:
IP CCTV
Wi-Fi access point
VoIP phone
Other PoE equipment
The LPM-10A provides PoE detection capability to assist with checking PoE information at the network connection.
Do not assume every RJ45 wall point is connected in exactly the same way.
Step 8: Check the Cable Length
Cable length measurement can provide additional information about an unknown installation.
For example, the outlet may appear to be only 15 metres from the network cabinet.
But the cable route could travel:
Above ceilings
Around corridors
Through cable trays
Between rooms
Through a riser
The FNIRSI LPM-10A cable length measurement function can provide useful context when investigating the existing cable.
Step 9: Connect a Known-Good Device
Once the physical network path has been checked, connect a known-good device where appropriate.
This may be:
Laptop
Network test device
Known-good IP camera
Other suitable network equipment
Now determine whether the network connection behaves normally.
If the physical cable appears good but there is still no network access, move deeper into network configuration.
Cable Is Good but No Internet
This does not automatically mean the LAN outlet is faulty.
Possible network-side causes include:
No DHCP
Incorrect VLAN
Switch-port configuration
No upstream connection
Router issue
Network security policy
Incorrect IP settings
The cable tester helps investigate the physical path.
Network configuration may require additional tools or administrator access.
Unknown LAN Point in a New Office
This is a very common situation.
A company moves into a previously occupied office.
There may already be 30 or 50 LAN points installed.
Before paying to install completely new cabling, it may be worthwhile to evaluate the existing network infrastructure.
A technician can systematically check:
Which points are usable?
Where do they terminate?
Which cables have problems?
Which switch ports are involved?
Which points need re-termination?
Existing cabling may still have value.
Unknown LAN Point After Renovation
Renovation creates another common problem.
A contractor moves partitions and desks.
Several old network points remain.
Some are reused.
Some are abandoned.
Some labels no longer match.
Before connecting staff computers, identify and test the required points.
This reduces confusion when employees move into the renovated area.
Can You Reuse an Old Network Cable?
Potentially, yes.
But age alone does not tell you whether a cable is suitable.
Consider:
Physical condition
Termination
Cable type
Installation condition
Required network performance
Application
A basic troubleshooting tester can provide useful information, but it does not replace professional cable certification where formal performance verification is required.
Can LPM-10A Certify Existing Structured Cabling?
No.
The FNIRSI LPM-10A should be considered a network installation and troubleshooting instrument, not a replacement for a professional structured-cabling certification tester.
It is useful for:
Identifying
Tracing
Basic wiring checks
Cable length information
PoE checking
Port identification
For projects requiring formal certification against cabling standards, use the appropriate professional certification equipment.
Reusing LAN Point for IP CCTV
An old office network point may sometimes be considered for a new IP camera.
Before doing so, check the complete path.
You need to know:
Where does the cable terminate?
Is the wiring normal?
Which switch will it connect to?
Is suitable PoE available for the intended device?
Is the network configuration appropriate?
Do not install the camera first and investigate the network later.
Reusing LAN Point for Wi-Fi Access Point
The same principle applies to a new Wi-Fi AP.
An existing ceiling or wall network point may appear convenient.
But first determine:
Cable condition
Cable route
Switch connection
PoE availability
Network configuration
A few minutes of testing can prevent a much longer troubleshooting job later.
Reusing LAN Point for Office Computer
For a normal workstation, the process may be simpler.
Check:
Wall outlet
↓
Cable wiring
↓
Cable destination
↓
Patch panel
↓
Switch port
↓
Network connection
If all stages are suitable, the point can then be put back into service.
Don't Install New Cable Too Quickly
When an old LAN point does not immediately work, some contractors may recommend installing a completely new cable.
Sometimes that is necessary.
But first determine what is actually wrong.
The problem might only be:
Missing patch cable
Loose termination
Incorrect switch connection
Old label
Unused switch port
A relatively simple repair could restore the existing network point.
When Should You Consider Replacing the Cable?
Replacement may be more appropriate when testing and inspection indicate problems such as:
Physical cable damage
Repeated connection faults
Unsuitable existing cabling for the required application
Poor installation condition
Renovation damage
Difficult or unreliable previous repairs
The decision should be based on the installation condition and required performance rather than guesswork.
A Better Workflow for Unknown LAN Points
Use this sequence:
Inspect the outlet
↓
Check wiring
↓
Trace the cable
↓
Identify the patch-panel position
↓
Identify the switch port
↓
Check PoE if relevant
↓
Check cable length if useful
↓
Test network connection
↓
Label and document the point
The final step is important.
Once you identify the cable:
Label it properly.
Do not leave it unknown for the next technician.
FNIRSI LPM-10A for Existing Network Maintenance
The FNIRSI LPM-10A is particularly useful when working on networks you did not originally install.
Instead of asking only:
“Does this cable have continuity?”
you can investigate several practical questions:
Where does it go?
Is the wiring normal?
Approximately how long is it?
Is PoE present?
Which switch port is connected?
This makes a multifunction tester useful for maintenance and renovation work.
FNIRSI LPM-10A Network Cable Tester Malaysia
Before reusing an unknown LAN wall outlet, understand the existing network path first.
The FNIRSI LPM-10A combines cable tracing, wire-map testing, cable length measurement, PoE detection, port identification and network-related testing for practical network troubleshooting.
It is suitable for technicians working with:
Office networks
CCTV systems
Wi-Fi access points
Factories
Warehouses
Commercial buildings
Existing structured cabling
For FNIRSI LPM-10A availability, technical enquiries or help selecting a suitable network cable tester, contact MTM Precision Sdn Bhd.
MTM Precision Sdn Bhd
Showroom & Service Centre:
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Tel: 03-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com
Website: www.mtmpre.com.my
If you have an unknown LAN point in an existing office, WhatsApp us a photo of the RJ45 outlet, patch panel, network cabinet or existing cabling and explain what you are trying to identify or reuse.
Supply and enquiries throughout Malaysia, including Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.
06 Oct 2026
