Gary VanRemortel | KLX-135A Comm Radio Issue | |||
Gary VanRemortel | KLX-135A Comm Radio Issue |
Subject: Re: KLX-135A Comm Radio Issue From: Christopher Cee Stone (rv8iator@gmail.com) Date: Tue Apr 23 - 6:25 AM I've had a similar experience with failing electrolytic aluminum can caps. Interesting in that all the failures have been in aluminum radial leaded caps. Never have had a failure of axial leaded. Also the failures were in power circuits and the voltage rating was near the working voltage. Nominal circuit voltage of 14 volts used a 25 volt part. Thanks for your post, another good data point. Chris RV-8 x 2, Long EZ On Mon, Apr 22, 2024 at 10:32=AFPM Gary VanRemortel <garyvanremortel@ gmail.com> wrote: > Just a report from the field regarding aging avionics devices with > electrolytic capacitors. > > Like many of you early builders, I installed the Bendix king KLX-135A > panel mount GPS/Comm when I built my RV-6A S/N 22665 in the mid to late > '90s. Electrolytic capacitors have a finite life of somewhere between 20 > and 30yrs regardless of hours of operation. Over the years the unit had > performed well, having just the need for a replacement Tadiran battery on > the Digital Board, new LCD and replacement of the optical sensors on freq > selector. > > Yesterday the unit died on the taxiway, accompanied by the pungent toaste d > fish smell of a fried electrolytic capacitor. I bought the entire > operation and maintenance binder for the unit many years ago off Ebay, so > have all the service info, parts lists, assembly drawings and schematics. > Upon disassy C1 (47uF 50V) on the Power Supply Assy had exploded, leavin g > a fried hole nearly all the way thru the PCB and dielectric everywhere. It > had clearly shorted. C1 is the power filter on the DC input power line s o > it charges up every time power is cycled ON. I repaired the PCB with epo xy > and reinstalled a better capacitor with higher voltage rating. The > shorting of C1 on the Power Supply PCB took out the axial leaded fuse F1 on > the comm/receiver PCB and these are readily available from Amazon for abo ut > $1 apiece (Littelfuse 251007 > https://www.amazon.com/dp/B00LQSF6NQ?psc=1&ref=ppx_yo2ov_dt_b_product _details > ) > > It may be wise to inspect your unit if yours is as old as mine is. Blue > skies. > > -GV >
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