Repair Guide for Mk3 (3.1b / GHD3 / SS / SS2 / MS) GHDs

1) Start

2) Light comes on

3) They are dead - no light

4) Taking them apart

5) Testing the cable

6) Testing the thermal fuse (GHD 3.1B and SS2 only)

The thermal fuse is the two brown wires coming out of the ceramic plate assembly on the switch side arm of the GHD's. If you put a multimeter across those two terminals (with them disconnected from the mains!), then it should be be close to zero ohms (maybe 1 ohm at worst). This means that when testing the thermal fuse you should see a similar output on your multimeter display as if you touched your meter's probes directly together. Don't get caught out by "OL" which means the thermal fuse is open circuit. If you've got an intermittent pair of GHD's, then you may want to try pulling / pushing on the wires slightly whilst measuring the resistance to see if it's the thermal fuse that is causing this.

Note that a broken thermal fuse wire is rare, another rare occurrence is intermittant failure of the thermal fuse whilst being used but reads correctly when checked with a multimeter.

Instructions for replacing the thermal fuse can be found here.

If you need to buy a thermal fuse, then we sell them via the shop.

7) Testing the heaters

There are two heaters - one in each arm. They are connected to the PCB's with white/clear wires coming out of the ceramic plate assembly. When attached to the PCB, the heaters are in parallel so should measure 80 Ohms. If this is not the case, disconnect the heaters from the PCB and measure them independently - they should be 160 Ohms each. See the heaters page for spare parts and replacment guides.

The heater wires can break and cause an intermittant connection.

To check, gently tug on each element wire in turn, a broken wire will pull off with this gentle tug.

Tug both ends of the elements wires, where they screw to the PCB and where they enter the element assembly.

Replace any element that has a damaged wire.



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