Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Was aiming to talk to the owner on when to collect his NSX last weekend but been prevented from doing so with many new issues.

The worst one was the cracked door mirror housing.
It’s not the known issue of snapping off the hollow shaft of foldable mechanism but in fact, the actual base frame.

Don’t even know how it can happen without the manufacturing process issue (several small air pockets found) or previous partial damage as the cracked edge was just so straight line.
Fortunately, same colour new door mirror housing was still available but very expensive.

Just need admitting all these issues are part of dealing with the aged classic car but I must change my procedure as I always did the same process for years on so many cars including mine….


Speaking of known issues, even the capacitor leakage on many electronics components started showing much worse condition or even new failure modes recently.

Over the last few years, serviced so many electronics components such as the A/C CCU board, audio head unit, gauge cluster, Bose speaker amp, SRS controller, EPS controller, etc.

Photo of repairing work would look similar so I’ll just touch on them briefly and focus on sharing the recent new failure modes.





Just few examples of recent services.
All of them are different CCU boards with severe damages but nothing new and successfully refurbished all of them.






As mentioned previously, thank you to ‘BrianK’ at NSX Prime for helping me when I experienced problem dealing with this board.
Learnt a lot through his experience.

Also, ‘Heineken’ on here helped me on finding the replacement parts on many occasions.


For the CCU service, replacing the capacitor is just small part of the long-long process.

The main task is repairing other areas such as the damaged through-hole, re-connecting the dissolved tracks and spotting other failed components such as the Tr, diode, Zenor, etc.

While there is always a first time for everything, from what I saw on so many CCU board with DIY attempt, personally I recommend not try repairing by oneself.

After receiving the CCU boards that were serviced by the owner or someone else, 100% of them shown extra damages and resulted in extra time and cost for me to repair them.

The only people that I can trust for servicing these board is BrianK in US and Heineken in EU.





Recently, serviced this board and this one was quite interesting.

The owner told me that 75% of the time, the CCU operated fine.

However, for the rest of 25%, the fan speed suddenly blasted at max speed regardless of the CCU control.

Pressing the button or turning the fan speed dial didn’t change the fan speed.

And even when the CCU was switched Off, suddenly the fan could start at full blast despite nothing shown on the display as the CCU was switched Off.


The usual severe capacitor leakage and had to remove extra components but nothing new.

Based on what I learnt previously, I knew it’s Tr related but none of them were faulty.

So, after spending fair amount of extra time, managed to refurbish the board, bench tested and installed on my NSX for testing it under real car environment.

Self-diag test to confirm all sensor input and actuator operation plus the Function & Operation check for manually testing each mode, vent, A/C compressor, water valve, etc control.

Everything worked fine and even covered some mileage over 1.5 day.

Then, parked the car under direct sunlight for few hours and the cabin temperature got really hot.

When returned to the car and ready to make the move, suddenly, the fan started blasting at max speed.

Just like what the owner reported, pressing any buttons or turning the fan speed dial didn’t change anything.

However, it only happened once and after power cycling, it just operated fine for the rest of the day.





Applying cold spray to the specific Tr didn’t re-create the same issue but can’t just leave it as is so removed two Tr, Q11 and Q12.

Both tested fine on the bench but from the past experience, replaced Q12 and re-used Q11.

Since the issue only happened once and couldn’t reproduce it before replacing the Tr and removed Tr were both fine that I decided to cover huge mileage for testing purpose.




At the end, covered 128miles of test driving session.


The CCU board returned to the owner and no more issues.



That was quite a challenge....


Kaz