ZP90 SMPS capacitor replacements

  • 29 November 2021
  • 5 replies
  • 496 views
R

I am recapping my ZP90 at 12 years old. The caps mostly appear good, apart from the 1800uF on the 3.3V supply, which has a bulging top. I think its testamount to a good design that these units last this long. I leave mine switchedd on all the time, with 230V nominal mains.

These are the main capacitors, all originally by Jamicon, to consider replacing. They should be replaced with parts with same or better ripple current, life hours, and similar ESR. I avoided organic polymer etc, which might seem an upgrade, but which could lead to loop instabilities. My cap choices were rather limited by stocks.

400V 22uF main reservoir. 20mm long maximum. I am going to use https://hu.mouser.com/ProductDetail/Wurth-Elektronik/860241378003?qs=sGAEpiMZZMsKEdP9slC0YVUSgIC2sJFYWYuR0ZnncGk%3D

22uF 35V C104 - low stocks meant I am not going to worry changing this. value for info. Its the aux supply for the switcher IC.

C206 1800uF 6V3 105c Jamicon MZ 18 tall dia 10 pitch 5. I will use https://eu.mouser.com/ProductDetail/Nichicon/UHW0J182MPD?qs=sGAEpiMZZMtXHE36kCvv31lk8pGsgMbjZyo23Sz28Mk=

C207 1200uF 6V3 105c JAmicon WG 12 tall dia 10. I will use https://hu.mouser.com/ProductDetail/Rubycon/63ZLJ1200M10X125?qs=sGAEpiMZZMv0NwlthflBi5L7Q9U6tnPNnxj37RFa5A8=

C202 100uF 25V JAmicon WL dia 6.3 pitch 2.5 these dont have much load on them, I am replacing, but didnt really find sufficiently better parts to put as a link here.

C203 47uF 35V JAmicon WL dia 5 pitch 2.5

I think in most cases replacing the caps I have put the links to will give these great ZP90s a further lease of life, indeed, these capacitors I would expect to last a really long time.

 

 

 

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5 replies

James L.
Badge +17

Hi @RichardV,

 

Thanks for sharing your parts choices and process.

I know we have a fair few people on the Community that have replaced components in their older products in the past, and hopefully this thread will help someone in the future. :slight_smile:

Mark good posts by pressing the like button, and select the best answer on questions you've asked to help others find solutions.
E

@RichardV  Do you happen to know if there are ‘lytics in series with the analog outputs?  Mine plays fine via the digital port but is raspy and chokes on both analog left and right outputs (both variable and fixed).  (I need the analog outputs as well because Zone 2 in my system amplifier does not support digital inputs).

 

Thanks,

Don

 

E

@RichardV  For some reason I can’t edit my original post any more.  But I found out that bad power supply caps, specifically C203, can also cause the issue I was having.  Temporarily bridging it with another cap eliminated my problem.  Now to go grab some decent Nichicon, Rubycon, etc. and do a p/s rebuild…thanks much for sharing not only the capacitor values, but even their sizes and lead spacings!

 

Don

 

R

Interesting to hear, Don, what happens when the PS capacitors really get old...my unit was still working fine at 12yrs..but in fact I found that the first capacitors (directly on the diodes) of both 3.3 and 14.8V rails had totally failed, meaning I had 1.6V pp ripple on the 14.8V output, and the 3.3V output had sagged and also had considerable ripple. Looks like I caught mine just in time, I can certainly imagine more damage occuring if these are not replaced in time. After replacing the major PSU caps, the ripple on the 14.8V rail was down to 60mVpp, just showing how much the capacitors had degraded over time.

I have to comment though that the process is a difficult one, I did swear quite a lot doing it. Not for the faint hearted or inexperienced.

I would say it is best to gently and in a straight line unplug the two antennas on the top board on the PSU side, before taking the PSU out..you virtually have to do this to get the PSU back in, so might as well start off doing it. Take care to line the antenna connectors up carefully and squeeze them gently back on, they are not designed for more than a handful of insertions, and break very easily, as I have found on many occasions in the past.

One has to mention that my unit has probably run for over 100,000 hours...similar to 3 million car miles, just to keep things in perspective.

E

Sorry for the delay, Richard, it’s been pretty crazy here lately.  Yes, the power supply PCB doesn’t particularly like to “let go” of the capacitor leads, even with semi-professional equipment (Hakko desoldering tool).  I’m sure a pre-heat would have helped a lot, but I didn’t want to go to through all the hassle of removing the PCB from the chassis.  For the same reason, I chose to just leave the 22 uF bulk capacitor alone, as it’s not subject to anywhere near as much abuse as those caps on the output(s) of the regulator.

I ended up just leaving the antennas connected.  Instead of fighting with the plugs (which seemed to have some hot glue or something retaining them in my ZP90), I unscrewed the antenna, mount and all, for the cable which was giving the most trouble and simply lifted it out of the chassis.  Careful handling allowed me to work on the supply at that point.

I have modified my HT setup slightly so the Sonos isn’t powered at all unless the amp is on.  That does, of course, come with its disadvantages, since you have to wait for the thing to boot before you can enjoy any music.  And of course it completely forgets whatever playlist was loaded.  It seems a pretty small price to pay for increased longevity...but if it drives me too crazy I’ll put it back the other way, lol.

Don

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