AB Repair PIC fault code list. These only apply to our PICs.
Important, on both the mk 4 and 5 pcbs there is a common fault that can cause the heaters to brake or crack. The fault happens when the voltage detection circuit fails on the pcb and the IC thinks the mains voltage is lower and there for will operate the GHD in the 110v mode as it would in the US. It is normally one of the 1 megohm resistors that fails.
Plans for version 4 ICs. When we release our new version 4 IC for the MK4/5 pcbs we plan to have it show fault codes by flashing the led a number of times to represent the the error code. In line with our new S7N261 Gold or GHD Max S7N462 ICs. Find out more about our S7N ICs here
New MK4 and MK5 V2 ICs
| LED Status | Buzzer Status | Fault |
| on (no flashing) | Silent | Check IC soldering, Check there is around 4.5v across capasitor C5. Check if R1 or D2 is faulty. |
| MK5 LED on/ MK4 yellow (no flashing) | Beeping | 240v mode with thermistor disconnected, faulty thermistor or to cold. This is for testing the voltage detection is working. |
| MK5 LED off/ Km4 red (no flashing) | Beeping | 110v mode with thermistor disconnected, faulty thermistor or to cold. This is for testing the voltage detection is working. |
| Slow flash | Slow beep | IC has gone to sleep because it has eather detected a heater fault at startup, thermistor has came disconnected or 20 min timer has ranout. |
Mk4.0 Round
This is our original code and does not have any extra fault codes added.
Mk4.2 Square v1
| LED Status | Buzzer Status | Fault | Reason for fault code |
| on (no flashing) | Silent | Check IC soldering or R1 or D2 is faulty. | The IC can not detect the line frequency |
| Yellow (no flashing) | Beeping | 240v mode with thermistor disconnected, faulty thermistor or to cold. | This is also for testing the voltage detection is working. |
| Red (no flashing) | Beeping | 110v mode with thermistor disconnected, faulty thermistor or to cold. | This is also for testing the voltage detection is working. |
| Flashing red and yellow | Silent | IC is on the wrong version of PCB (it is for a round buzzer pcb) | |
| LED wrong colour while running |
Some versions of the switch side PCB have the LED fitted in the opposite direction. Switch the 2 LED wires around on the switch side PCB |
MK5 Round and Square v1
| LED Status | Buzzer Status | Fault |
| on (no flashing) | Silent | Check IC soldering, R1 or D2 is faulty |
| on (no flashing) | Beeping | 240v mode with thermistor disconnected, faulty thermistor or to cold. This is for testing the voltage detection is working. |
| off | Beeping | 110v mode with thermistor disconnected, faulty thermistor or to cold. This is for testing the voltage detection is working. |
| Flashing | Silent | IC on wrong version of PCB |