ghd resistors: R8 and R11
R8 and R11 control the current in a ghd's circuit. Why they fail, when to replace them, and why higher power rated parts help.
12 August 2024Read
Most of our repairs are on the older ghd v3, v4 and v5 models, but we also repair the newer ghd Gold S7N261 and its wide plate version, the ghd Max S7N421. One part we replace on these is a MOSFET, marked Q4 on the circuit board.
What is a MOSFET?
A MOSFET is a type of transistor. In electronics it's used as a switch with no moving parts, turning the flow of power on and off very quickly under the control of the circuit board. Because it handles power and sits in a hot appliance, it works hard, and like any component it can fail.
A very small part
The MOSFET on a ghd Gold board is tiny: less than 2mm long and only just over 1mm wide, with three legs soldered directly onto the surface of the board. Removing a failed one and fitting a new one cleanly, without damaging the board or the parts around it, takes magnification, fine soldering equipment and experience of board level repair. It isn't a job for a standard soldering iron.
Signs of a failed MOSFET
On the ghd Gold, beeping is normally caused by a failed MOSFET together with a failed heater element, so we usually replace both.
What we do
We diagnose the fault first, so we know the MOSFET is the cause rather than guessing. If it is, we remove the failed part, fit a replacement and test the straighteners, including the temperature, before they go back. As with every repair, we safety check them and tell you the price before any work starts. Repairs to the ghd Gold are £39.99 plus return postage.
A few faults on the Gold can't be repaired. If yours turns out to have one of them, we'll tell you, and you only pay return postage, or we can dispose of them for you.
Which models?
- We repair: ghd Gold S7N261, Max S7N421 and Mini S7N151, the 2022 ghd Original, plus ghd v3, v4 and v5 models.
- We don't repair: ghd Platinum, Platinum+, Chronos or Eclipse models.
Not sure which model you have? See which ghd model do I have?
Book a repair
Choose "ghd Gold, Max or Mini" when you book your repair, and we'll take it from there.
Because of its size and the mains powered board it sits on, replacing this MOSFET is specialist work. Please don't attempt it yourself unless you're experienced in surface mount soldering.
