Motherboard Connector Flex Cable
Samsung Galaxy S21 FE 5G Motherboard Connector Flex Cable Replacement
- Fits
- Samsung Galaxy S21 FE 5G
- Fixes
- Damaged main board flex
- Quality
- Brand new, OEM quality
- Fitting
- Professional install
Overview
What this part is
Inside the Galaxy S21 FE 5G, a flex cable carries power and signals between the main board and the lower board. If it is torn, pinched during a repair or damaged by liquid, parts of the phone stop talking to each other.
Typical results are no charging, a dead screen, no signal or a phone that restarts by itself. This flex is a technician's part: the phone must be opened and the fault should be traced first, as other parts can cause the same symptoms. Check the photos to match the connectors to your phone.
Compatibility
Specifications and compatibility
- Part
- Motherboard Connector Flex Cable
- Compatible with
- Samsung Galaxy S21 FE 5G
- Model numbers
- SM-G990B
- Does not fit
- Galaxy S21, S21+, S21 Ultra or any other model
- Fixes
- Faults caused by a torn, pinched or corroded main board connector flex
- Does not fix
- Main board chip faults, a failed battery or a damaged screen
- Quality
- Brand new, OEM-quality motherboard connector flex cable. Tested before dispatch.
- Brand
- Unbranded, compatible with Samsung Galaxy S21 FE 5G
- In the box
- 1 × motherboard connector flex cable for the Galaxy S21 FE 5G.
- Colour
- As shown in the photos
- Installation
- Professional installation recommended
- Supplied by
- Supreme Phone Parts Ltd, Manchester, UK
Before you order
Is this the right part?
Signs it needs replacing
- The phone stopped charging after a repair or drop
- The screen stays black but the phone still vibrates
- The phone restarts itself or loses signal
- The flex is visibly torn, creased or corroded
How to check your model
Open Settings › About phone. The Model name should read Galaxy S21 FE 5G. The Model number should start SM-G990.
The Galaxy S21 FE has a 6.4-inch flat screen and three rear cameras. The standard S21 is smaller, with a 6.2-inch screen.
Professional installation
How a technician fits this part
- Power the Galaxy S21 FE 5G off and warm the edges of the back cover to soften the adhesive.
- Lift the back cover carefully and disconnect the battery before anything else.
- Remove the screws and covers to reach both ends of the connector flex.
- Unclip and peel out the old flex, then lay the new flex in the same route and press both ends home.
- Reconnect the battery and test charging, display, touch, signal and sound before closing.
- Fit new back cover adhesive, close the phone and press evenly while it cures.
Check that the part matches the device before fitting it or removing any adhesive backing. Once a part has been fitted, it cannot be returned for a change of mind. Faulty parts are always covered.
FAQ
Frequently asked questions
Will this fit my Galaxy S21 FE 5G?
Yes, if Settings › About phone shows Galaxy S21 FE 5G. Check the model number too.
Does it fit the standard Galaxy S21?
No. The S21 FE is a different phone inside. This flex is listed for the S21 FE only.
Will it fix my phone that does not charge?
Only if the connector flex is the cause. A worn charging port, battery or main board fault can look the same, so a technician should test first.
Is it made by Samsung?
No. It is a brand new, OEM-quality motherboard connector flex cable made to fit the Galaxy S21 FE 5G, and every part is tested before dispatch.
Should I fit it myself?
We recommend professional installation. The flex runs across the inside of the phone, the back cover is glued, and the battery must be disconnected safely.
How quickly will it arrive?
Orders placed before 4pm on a working day are dispatched the same day from Manchester by Royal Mail Tracked. Delivery is free on UK orders from £5.
Prepared by the Supreme Phone Parts team, Manchester. Last updated September 2026.