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Power Issues — Troubleshooting GuideUpdated a month ago
This guide will help you diagnose and resolve power issues with your aF4. The fastest way to identify what's wrong is to check the small red LED above the power button — it tells you immediately which type of problem you have.
Step 1 — Check the red LED above the power button
When the power supply is connected to both the wall and the aF4, a red LED above the power button should illuminate. This LED is your primary diagnostic tool.
No red LED — power delivery problem
If the red LED is not lit, the aF4 is not receiving power. Work through the following checks in order:
Inspect the power supply brick: Check the power supply for visible signs of damage — scorch marks, a burning smell, a cracked casing, or a cable that has been sharply bent or pinched. If you see any of these, stop using the power supply immediately.
Check the plug connections: Ensure the power cable is fully seated at both ends — at the power supply brick and at the port on the back of the aF4. A partially inserted connection is one of the most common causes. Unplug both ends and firmly reseat them.
Try a different outlet: Plug into a different wall outlet, ideally on a different circuit. Plug the power supply directly into the wall — avoid extension cords or power strips where possible to rule out any intermediate issues.
If the red LED still does not illuminate after all of the above:The power supply has failed and needs to be replaced. The aF4 power supply is a user-replaceable part — you do not need to send the unit in for service.
Order a replacement directly from indaquatics.com. If you are unsure which power supply to order, submit a support ticket with your serial number and we will confirm the correct part for your region.
NOTE: On rare occasions - replacing the power supply will not remedy the issue and the entire unit will need replacement or repair.
Red LED is lit — button or PCB issue
If the red LED above the power button is illuminated, the power supply and connection are good. The issue is either with how the power button is being pressed, or in rare cases, a failed main PCB.
Check your button press technique — this is the most common cause: The aF4 power button requires a firm press held for a full 3 seconds to power the unit on. A brief tap, a light press, or releasing before 3 seconds will not start the unit. Press the button firmly and hold it — count to 3 before releasing — and wait for the display to activate.
If the unit powers on after a firm 3-second press, no further action is needed.
If a firm 3-second press does not power the unit on: This is uncommon. If the red LED is confirmed lit, the cable connections are secure, and the unit will not respond to a firm 3-second button press, this may indicate a failed main PCB.
A failed main PCB is not a user-serviceable issue. Submit a support ticket with the following information and our team will assess your options:
- Your serial number (sticker on the underside of the aF4)
- Confirmation that the red LED above the power button is illuminated
- Confirmation that you have tried a firm 3-second button press
- Your order number or proof of purchase
Quick reference
| Red LED above power button | Likely cause | Next step |
|---|---|---|
| Not lit | Power delivery issue | Check connections, try different outlet, replace power supply |
| Lit | Button technique or PCB issue | Press firmly for 3 seconds — if no response, contact support |
Related articles
- Blinking LED Guide — if the temperature LEDs are flashing after powering on
- Over-Temperature Fault: Remedies & Prevention Guide — if the unit shuts down unexpectedly after powering on
Still not resolved? Submit a ticket and our team will help diagnose it.