do you like to replace capacitors? - Videokarma.org TV - Video

wiseguy · #1 01-18-2003, 03:02 PM

this is sort of off topic BUT,if you think old televisons have a lot of capacitors then take a look below..
i have just finished replacing 177 surface mount lytics in this digital VTR,(panasonic DVC pro),these only have a life of around 2000 hrs,this deck is only 3 years old..the old caps are in the plastic bag i am holding,they are tiny,it does not even look like 177 capacitors..
i prefer parts that have leads..

enjoy!!
terry

Lefty · #2 01-18-2003, 03:09 PM

Wow only 2,000 hours. I could swear that the military MTBF reliability data for capacitors I once read was much much higher then that.

What is the failure mode of these capacitors? The only failure mode I could think of that would fail 177 caps would be some kind of power supply failure that caused all the capacitor's maximum working voltage to be exceeded. That certainly wouldn't be the caps fault, just the results of a different failure.

Lefty

wiseguy · #3 01-18-2003, 03:46 PM

these SMD lytics are used in broadcast-consumer,it is a common failure,nothing causes them,but maybe high heat,I was told by a panasonic technical rep that they only have a shelf life of like 3500 hrs or something like 3 years,i ran out of 10mfd@16wv,so to get this deck done i had to use a couple of regular same value type cap,actually it will last longer,but space is important..
terry

Lefty · #4 01-18-2003, 04:03 PM

Terry;

Interesting. We have been seeing SMT components showning up in most all the newer gear we use at work (industrial process control stuff) and dislike them mostly because replacement is pretty risky without proper equipment and training. Component level troubleshooting is getting to be a lost art. Remove and replace seems to be the solution these days.

So how did those caps fail? open circuit, short circuit, change value?

Lefty

***Eric H*** · #5 01-18-2003, 04:49 PM

That's outrageous that an expensive piece of gear like that needs recapped after only 3 years!

The engine control computers in cars use tons of surface mount stuff and they rarely fail despite being subject to temp extremes, humidity, vibration etc... so what's the deal with all these video products??

wiseguy · #6 01-18-2003, 05:50 PM

i wish i knew why they fail,i have talked to several tech reps,size and ease of manufacturing is all i hear about,interesting thing eric...i have a 94 corvette.. and last summer the bose CD player quit working,i removed the cd player itself from the delco bose radio..and guess what?? it was a matshushita cd player,and loaded with these SMD caps,i checked them and they all had high ESR,i replaced them and it works perfect,but the delco radio itself has regular can type lytics,you will find these type of caps in all kinds of electronics.BUT..it is rare you will find these type of caps in industrial-medical electronics,usually high temp small can types.
terry

kc8adu · #7 01-19-2003, 06:47 AM

doing a recap on a sony gv8 now.
full of sm lytics and all bad.
i think it is just poor quality caps.
i have a icom 2410h 2m/70cm transciever that is never turned off that is full of these caps and in a worst case environment(in a truck)that has been in use 6 years.it was used when i got it and the caps esr is lower than the new ones i have on hand.
so i know it is possible to make ones that last.

jshorva65 · #8 01-19-2003, 08:56 AM

The reason for the high failure rate of caps in video gear when the rates of failure of similar caps in GM engine controllers is much lower can be explained very simply. The problem is the "Subscription Model" strategy employed by some manufacturers (started by the Japanese, but adopted by others in "monkey see, monkey do" fashion). The model is based on the principle that technology advances so quickly as to justify the manufacture of devices with built-in failures planned to occur just before the device becomes superseded by a more desirable product. Like a magazine or newspaper subscription, the consumers are meant to throw away the outdated "issues" and buy the latest ones to replace them. The built-in failures force all consumers (not just tech-heads who insist on having the latest bells and whistles) to join the cycle. The disease has not spread to the auto industry YET because the automotive marketplace hasn't degenerated to that point yet. Automakers such as Daewoo and Kia haven't succeeded in putting GM and Ford out of business just yet like Sanyo and Sony have done to Fisher, RCA, Dumont and other manufacturers of built-to-last audio/video products.