Welcome!

By registering with us, you'll be able to discuss, share and message with other members of our community.

SignUp Now!

And...another successful Cluster repair (tachos mostly)

Another cluster arrived for repair on Monday afternoon, 2 March. I managed to diagnose and repair and ship it back within 48 hours (it was a pre-booked job).

No surprises, the usual failed IC on the tacho PCB. no needle movement as received.

Tacho removed from cluster and set up on my tacho tester, still dead - but 5 seconds of 100 degrees from a heat gun onto the IC and the tacho sprang into life and worked perfectly. Unfortunately, that "fix" doesn't last long, so I replaced the entire OEM PCB with my replacement design PCB, which uses automotive grade components. All straightforward to install - the hairiest bit is removing the tacho needle with extreme care. Calibration done on my tester, tacho reinstalled in cluster, retested on my cluster test rig and all good.

Pic of tacho with replacement PCB installed:
20260303_115807.jpg

Video of tacho on tester for calibration;


Pic of cluster on final, full function test:
20260303_120642.jpg

Two more repairs booked into my diary, but DM me if you have a cluster requiring a repair.
 
Another cluster turned around in 2 days and currently winging it's way back to the car owner in SWEDEN.

No tacho OR speedo operating, so I was thinking this could be an expensive and time consuming repair. In fact, the cause (which didn't take too long to diagnose) turned out to be a short circuit diode, costing pennies. It was a bit if a faff to remove it and replace with a new one from stock, as the gauge had to be removed from the CPU PCB, but straightforward enough.
 
Teaser - 3D CAD image of Speedo daughterboard that can be used to fix "errant speedo needle" issues, when caused by a (now obsolete) failed driver chip. It has taken some time to design and test the electronics, plus a tricky physical design to fit within the space limitations and available fixing points. I've even managed to retain the use of the existing speed calibration variable resistor on the CPU board.

I have just sent off an order for 5 PCB's to be manufactured. Hopefully, they will be perfect, but I'm allowing some time to do a tweak or two when I do some testing.
FD Speedo 3D 2.jpg
 
Back
Top