My latest recap..... The "#1 and "#2 circuit boards" out of an elderly Lexus LS400.
"The dash lights won't work when cold and the new circuit board is over $800"
It has high-voltage CCFL lighting for the instruments but surpisingly, the high-voltage section seemed OK and all of the larger NCC SXE series caps seemed to have pretty good ESR.
A little Internet research pointed me to the right place.... Most of the small caps that look like polymers had extremely high ESR! The best one was like 28 ohm, the rest returned no reading.
It seems that the fuel gauge and instrument lights are controlled by an onboard processor of some kind that needs just a little filtering to operate. 10, 1 and 4.7mfd doesn't seem like much but the lack of these tiny, SMD mounted caps kills the lights and the fuel gauge.
I didn't have time for pics of the board but I can add pics of the old ones.
In went some Nichicon PW of the same ratings and the cluster sprang back to life.
The original caps had their leads pulled through a plastic mount and bent over to form a SMD package. Getting the new caps in place was a little touchy as the originals were put on a hot board and I was using just an iron.
It's easy to cry "foul" and "bad, cheap caps" but this car was made in 1993 and is old enough to vote. 18 years seems pretty good actually.
It just reminds me that today's cars are way too complicated for my tastes.
Il stick to my Trabbi.
"The dash lights won't work when cold and the new circuit board is over $800"
It has high-voltage CCFL lighting for the instruments but surpisingly, the high-voltage section seemed OK and all of the larger NCC SXE series caps seemed to have pretty good ESR.
A little Internet research pointed me to the right place.... Most of the small caps that look like polymers had extremely high ESR! The best one was like 28 ohm, the rest returned no reading.
It seems that the fuel gauge and instrument lights are controlled by an onboard processor of some kind that needs just a little filtering to operate. 10, 1 and 4.7mfd doesn't seem like much but the lack of these tiny, SMD mounted caps kills the lights and the fuel gauge.
I didn't have time for pics of the board but I can add pics of the old ones.
In went some Nichicon PW of the same ratings and the cluster sprang back to life.
The original caps had their leads pulled through a plastic mount and bent over to form a SMD package. Getting the new caps in place was a little touchy as the originals were put on a hot board and I was using just an iron.
It's easy to cry "foul" and "bad, cheap caps" but this car was made in 1993 and is old enough to vote. 18 years seems pretty good actually.
It just reminds me that today's cars are way too complicated for my tastes.
Il stick to my Trabbi.
Comment