Why Does the Panel Brightness Knob Spin Freely With No Resistance?

مايو 07, 2026 Daniel W

SUPPORT · DESIGN EXPLAINED · NOT A DEFECT

Why Does the Panel Brightness Knob
Spin Freely With No Resistance?

Rowsfire Support Team | May 2025 | B107 · B737 · PMDG

Short answer: this is normal. The Panel Brightness knob is a rotary encoder — not a potentiometer. Encoders are designed to spin freely with no physical stop. The knob is working exactly as intended, and the dimming function works correctly in your simulator.

What customers are reporting

Some customers who receive the B107 notice that the Panel Brightness knob on the overhead panel rotates continuously without any friction, resistance, or end-stop. There's no "click" position and no point where the knob stops turning. This can feel unexpected — especially if you're used to traditional volume-style knobs — and may raise concerns about a hardware defect.

It is not a defect. Here's why.

Panel Brightness knob location — B107 B737 Overhead Panel (highlighted in red)

The technical reason — encoder vs potentiometer

STANDARD KNOB

Potentiometer

Has a physical sweep range (usually 270°). Provides resistance and end-stops. Common in volume controls and older sim hardware. Outputs an analog voltage level.

B107 PANEL BRIGHTNESS

Rotary Encoder ✓

No physical limit — spins freely in both directions. Outputs incremental pulses (up/down) rather than a fixed position. Fully compatible with PMDG's event-based input system.

The Panel Brightness position in the PMDG 737 does not accept potentiometer input — it is driven by incremental events (increase / decrease). A rotary encoder is the correct hardware choice for this, and it is the only type of input PMDG supports at this control position.

Why no friction? Friction and end-stops are properties of potentiometers. Rotary encoders are inherently frictionless and limitless — this is what makes them compatible with event-driven sim software like PMDG. The free spin you feel is the design working correctly, not a component failing.

How to confirm it's working

Load the PMDG 737 in MSFS and power on the aircraft. Rotate the Panel Brightness knob — you will see the overhead panel backlighting change in real time in the simulator. The function is fully operational.

If the backlighting does not respond, check that the Rowsfire App or MobiFlight profile is correctly loaded and the B107 is connected. Contact service@rowsfire.com if you need further help.

Back to Product Questions

Rowsfire App Update Error？Complete Fix Guide

75%

(231)

15%

(45)

(20)

(4)

(6)

266

Out of the box the board looks the part. Installation of knobs and covers took some time but it is all fun and makes you get up and close and personal with your new shiny board.
Software installation with the Rows fire app was easy once you know what you are doing but big disappointment the app only works with PMDG 737-800..very specific..I have all of PMDG 737, but no luck with the 600, 700, or 900. Not happy.
so on to Mobiflight and again more learning curves with that one if you have not used it before. But alas onse up and running, low and behold all PMDG 737 versions work like a charm. Have not tried the pmdg 777 yet.
I have had no chance so far to try it in a normal flight, I know people have complained about the Panel light knob just goes round and round and yes it does but it also dims the light just fine.
Do I reccommend? yes I do if you dont mind spend some hard earned cash.

I love my B107. I would give it 5 stars if there were not any problems. Right of the box the panel display knob spins 360 degrees with little if no adjustment at all. The background illumination is very dim or even sometimes it is normal. One of the first things I do once Zibo has loaded is to max out the display in the sim. I then load the Rowsfire app for the B107. In your video of the EGT the needle goes up to 8 which match the sim. On my board the gauge only goes up to 6 and almost returns to zero. I have tried many times calibrate through the Rowsfire app, but I have now learned now to live with it and just watch the gauge in the sim. Overall quality of the build is excellent. I cannot believe how heavy the board is. It is just the petty things that drive me crazy and for the price of the board I would think it would not have these issues. Whomever performed QC did not know what they were supposed to check or the boards would have never been shipped. Might seem trivial to Rowsfire but it is a major source of concern for anyone who bought the B107.

The b107 is the best part of my simulator.
Rowsfire Good Job❤️❤️🌟🌟

Installation was a hurdle. Could not get rowsfire app to work so had to use mobiflight. No smoking hasn’t worked for me but I don’t care for it. Outside of that, this elevated my flight sim experience to FL390. It has been really fun and immersive. For a launch product, I feel I got great quality especially for that price.

Absolutely fantastic works great really enjoying it. Hope Rowsfire make more Boeing B737 stuff like radio and transponder units like they do for the airbus

1 2 3

Why Does the Panel Brightness Knob Spin Freely With No Resistance?

Why Does the Panel Brightness Knob
Spin Freely With No Resistance?

What customers are reporting

The technical reason — encoder vs potentiometer

How to confirm it's working

You may also like

Rowsfire B107 B737 Overhead Panel In Depth Review by Flight Streamer

She Holds the Altitude. Seven Women Who Command the Sky.

Invitation to FlightSimExpo 2026 USA

Let customers speak for us

Why Does the Panel Brightness KnobSpin Freely With No Resistance?

What customers are reporting

The technical reason — encoder vs potentiometer

How to confirm it's working

SUBSCRIBE TO OUR EMAILS

Be the first to know about new collections and exclusive offers .

You may also like

Let customers speak for us

Why Does the Panel Brightness Knob
Spin Freely With No Resistance?

Be the first to know about new collections and exclusive offers.