Topics

Late 2465b A5 SMD cap replacements

Paul Amaranth
 

I'm acquiring parts to go through a 2465B and I seem to have
neglected picking up replacements for the smd caps on the A5
board.

Does anyone have sugestions for replacements? I noticed in one
pdf floating around they were replaced with solid tantalums. I'm
not quite sure about that. I surely do not want to use the junk
caps I have on hand for small project work.

thanks

--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows

 

Firstly, I offer a custom kit with ALL the EXACT component replacements, to save you the hassle of sourcing the wrong components, due to confusion, and/or lack of knowledge.
Secondly, I offer ONLY TTH replacements for the A5 SMD caps, and absolutely NOT Tantalum.
Thirdly, if you INSIST on doing the legwork yourself, I have posted a BoM in the Files section of this group (2018 July ...), to ensure that members source ONLY the CORRECT parts, and no other.

Menahem Yachad
CondorAudio

Jean-Paul
 

Paul you need to research the A5 SMD cap leakage threads, and go to EEVblog.....2465b teardown (64 pages !).

The caps leak corrosive electrolyte due to poor seals, the electrolyte flows and corrodes components and traces of the PCB.

Drill....remove, clean, Replacement with electrolytic caps NOT tantalum, replacement all damaged parts.

Send a good photo of the A5 for further information.

Bon courage


Jon

Chuck Harris
 

Tantalum would be ok for these capacitors, if you
can find any that will fit. The spacing of the pads
is for SMD electrolytic caps, and tantalum caps of
the same voltage and value tend to be longer.
(it has to do with the electrolytic caps sticking
up from the board...)

Also, and this is important: Electrolytic caps are
almost exclusively marked on the *negative* terminal.

Tantalum caps are almost exclusively marked on the
*positive* terminal.

Cleanup of electrolyte must be done with detergent
and water, with a good rinse. You can actually see
the electrolyte with the right wavelength UV light.

-Chuck Harris

Jean-Paul wrote:

Paul you need to research the A5 SMD cap leakage threads, and go to EEVblog.....2465b teardown (64 pages !).

The caps leak corrosive electrolyte due to poor seals, the electrolyte flows and corrodes components and traces of the PCB.

Drill....remove, clean, Replacement with electrolytic caps NOT tantalum, replacement all damaged parts.

Send a good photo of the A5 for further information.

Bon courage


Jon



 

I used solid tantalum caps on my 2465B A5.  The board had been slightly damaged by the leaking electrolyte and I had to make some repairs.  I included adding some extra pad length as part of those repairs so the solid tantalums would fit just fine.  I de-rated their voltage spec by about 3 or 4 to one.  I also sought out caps with an ESR of equal or less than the electrolytics that I used in the past for the A5.  FWIW, I see no problem with modern solid tantalum caps in light duty bypass applications if you de-rate their voltage specs by at least 2 to one.

On Monday, October 21, 2019, 09:29:18 PM CDT, Paul Amaranth <paul@...> wrote:

I'm acquiring parts to go through a 2465B and I seem to have
neglected picking up replacements for the smd caps on the A5
board.

Does anyone have sugestions for replacements?  I noticed in one
pdf floating around they were replaced with solid tantalums.  I'm
not quite sure about that.  I surely do not want to use the junk
caps I have on hand for small project work.

thanks

--
Paul Amaranth, GCIH            | Manchester MI, USA             
Aurora Group of Michigan, LLC  |  Security, Systems & Software
paul@...              |  Unix & Windows

Paul Amaranth
 

Thanks, the 3 items on the spreadsheet under A5 were what I was looking for.
The commercial, not so much.

I generally have a DigiKey order go out once a month or so, so that will get
added to the next one.

Still thinking about how to read out the NVRAM with the equipment I have.
Might have to break down and buy one of the cheap programmers, although it
shouldn't be that hard to throw one together with an arduino and a few glue
chips. Writing to the NVRAM or a FRAM is not much of a problem.

Although not directly supported, I have a procedure to read it using my Data I/O 29B.
Have to find another chip to try that first though. Still have to write the new one.

Paul

On Tue, Oct 22, 2019 at 02:43:49AM -0700, M Yachad wrote:
Firstly, I offer a custom kit with ALL the EXACT component replacements, to save you the hassle of sourcing the wrong components, due to confusion, and/or lack of knowledge.
Secondly, I offer ONLY TTH replacements for the A5 SMD caps, and absolutely NOT Tantalum.
Thirdly, if you INSIST on doing the legwork yourself, I have posted a BoM in the Files section of this group (2018 July ...), to ensure that members source ONLY the CORRECT parts, and no other.

Menahem Yachad
CondorAudio
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows

Paul Amaranth
 

Thanks for that advice Chuck. I don't think they are leaking yet, but
the UV lamp idea is a good double check. It will get a thorough washing
in any case.

Paul

On Tue, Oct 22, 2019 at 10:00:54AM -0400, Chuck Harris wrote:
Tantalum would be ok for these capacitors, if you
can find any that will fit. The spacing of the pads
is for SMD electrolytic caps, and tantalum caps of
the same voltage and value tend to be longer.
(it has to do with the electrolytic caps sticking
up from the board...)

Also, and this is important: Electrolytic caps are
almost exclusively marked on the *negative* terminal.

Tantalum caps are almost exclusively marked on the
*positive* terminal.

Cleanup of electrolyte must be done with detergent
and water, with a good rinse. You can actually see
the electrolyte with the right wavelength UV light.

-Chuck Harris

Jean-Paul wrote:
Paul you need to research the A5 SMD cap leakage threads, and go to EEVblog.....2465b teardown (64 pages !).

The caps leak corrosive electrolyte due to poor seals, the electrolyte flows and corrodes components and traces of the PCB.

Drill....remove, clean, Replacement with electrolytic caps NOT tantalum, replacement all damaged parts.

Send a good photo of the A5 for further information.

Bon courage


Jon






!DSPAM:5daf0bac69004215715320!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows