LOS in router stands for Loss of Signal. Generally, the LOS light in the router is off, which indicates that everything is right with the router and network.
When this light starts blinking red, it means something is wrong with your network, and you won’t be able to use your internet.
There have been reports from users having PLDT routers that their LOS light blinks red. If you are here on this article searching for ways to fix this issue, then this article will help you.
We have listed all the ways you can fix the PLDT router LOS blinking red:
What Causes PLDT Router LOS Blinking Red?
A blinking red LOS light is followed by no network connection, i.e., whenever you encounter this light, you will face internet issues.
When your internet is stable and working fine, the LOS light will be off, and you will see the PON light in constant green.
But what are the causes of PLDT Router LOS blinking red? This issue can be encountered due to various reasons, such as:
- Damaged fiber optic cables or damaged connectors are the most common causes of this issue.
- You can face this issue if you have any pending internet bills.
- Another common reason behind facing this issue is the faulty router. Not only this cable but if your router is damaged or faulty, then that can also cause this issue.
- If your line is going under maintenance or has some fault at the end of the ISP, then you will face internet issues with the PLDT router LOS blinking red.
- If your router’s settings have been tampered with and they are misconfigured, then that can also become a reason for facing this issue.
Fix PLDT Router LOS Blinking RED

In most cases, this issue is fixed on its own. If your PLDT Router LOS light is blinking red, it will likely be fixed on its own after some time if the issue is not from your end. Here’s what you can do to fix the issue:
Ensure Optic Fiber is Not Damaged
This issue is generally encountered due to damaged optic fiber cables. The optic fiber cable connected to the router is delicate and easily damaged.
If the cable is pressing against some object or is stretched, then that can damage the cable and cause this issue.
Look for the signs of wear and tear to ensure whether your cable is damaged or not. If your cable is damaged, contact your ISP to replace the cable. If your cable is not damaged, try this article’s next step.
Restart Router
Another troubleshooting step to follow is restarting the router. Here’s how you can do it-
- Press the power button on your router and wait for the lights to go off. Once all the light turns off, your router is off.
- Unplug the power cable from the power source and wait a few seconds.
- Plug the power cable back into the power source, and then turn on your router by pressing the power button.
Pay Pending Bills
You should never leave your bills pending. If you have any unpaid bills from your ISP, then you must pay them to avoid disconnection.
If your internet is disconnected for unpaid bills, your PLDT router will show a blinking LOS light. To avoid such issues, paying the bills before the due date is best.
Check For Loose Cables
If the optic cable is not connected properly and is loose, then that can also cause this issue. You must check whether the cable is connected properly to the router.
You can unplug the optic fiber cable and connect it back to the router to avoid any loose connections.
If you still face the issue, unplug the fiber cable again, clean the tip of the cable and the port on the router, and then plug the cable back into the router. This should fix the issue for you.
Ensure Your Router is Not Damaged
If your PLDT router fell from a place or is damaged due to some reason, then that can also cause this issue. The damage can be both internal and external. You can check for external damage by checking the body of the router.
But what about the internal damage? Try shaking your router and check if you hear any sounds of broken internals.
If your router is damaged, then you will have to replace it. If you bought the router yourself, you can contact your router’s brand for the same. In case the router was given to you by the ISP, then contact your ISP to replace the router.
Contact ISP
This issue can also be from the end of the ISP. This generally happens when the internet line is damaged or under scheduled maintenance.
If that is the case, you will have to wait for some time, and then the issue will be fixed. ISPs notify the users about the ongoing maintenance and when it will be fixed, so if you have been notified about it, wait for the given time.
Not only scheduled maintenance, but if your network settings have been misconfigured from the ISP’s end, then that can also cause this issue. You can contact your ISP for the issue you have been facing and ask them to fix it for you.
Bottom Line
That’s it for this guide; we hope this article helps you solve the issue. If you face issues with the steps in this guide or your issue is still not solved, then you can comment below, and we will surely help you.