Repairing the instrument Cluster lighting of my Alfa Romeo Giulietta QV
I really like my Alfa Romeo Giuletta QV and it makes me smile everytime i drive it. But as it is with italian Cars, sometimes things go wrong on them.
On my Car the Lighting of the Fuel Gauge only worked sometimes and it went dark more frequently every week. It isn't anything important, but a bit annoying after some time, so i wanted it to be fixed. With that i removed the Dash from my Car, disassmebled it until i had the bar PCB in my Hand and got to work.
Take a look at the Video below for some information on the Repair, it is german but has English Subtitles:
In the End i repalced all 14 white SMD LEDs for the lighting on the PCB including the broken ones. Instead of 100€ or more and a week without a car for a professional repair i only payed 1,50€ for the SMD LEDs and spend an evening to replace them on the PCB. I also had a lot of fun working on this little Project and i now have a Instrument Cluster that lights up like new from the factory :)
While working on the PCB i also took a close look at all the components that are on it and researched a bit what they do. Here is a short List of the Chips i found:
- Renesas D70F3422GJ(A) - Main CPU / MCU
- Infineon TLE4275 - 5V Voltage Regulator (12V in -> 5V out)
- Infineon TLE4251 - Low Drop Voltage Tracker
- TI ULQ2003AT - Driver for the Motors of theGauge Needles, 3 on Board.
- ST LM2904 - OpAmp, possible for the CanBus Transmission
- NXP TJA1021 - CanBus Transreceiver
- NXP 74HCT4051D - 8bit Multiplexer, maybe to save IO Pins?
NOTE: You can use these pins to supply the dash with Power on your Desk: