IcePower 200ASC amp module

[Gareth Magennis]

Hi,

can't find any schematics for this module - its a Bang & Olufsun combined
SMPS/Class D audio amp PCB.

The one I have has the exact same fault as this one:
http://forum.recordere.dk/uploads/36113/icepower3.jpg


Blown cap (presumably), but no way of finding out what it was.
There are other photos on the Interweb of this board which show the unmarked
device not blown up.

There's about 330v DC across the remains, and my amp module still works
without it.



This is in a powered Studio Monitor Sub, seems these modules are reasonably
popular in this kind of thing - B&O would not sell these to the public,
though I read on a forum while Googling today that they might now, but are
prohibitively expensive.


Any smart guesses what I should be putting in there? One end goes to the
three paralleled resistors which are very low ohmage and I guess current
sense at ground, the other goes to the first pin of the transformer which is
at high HT.


Cheers,


Gareth.

[N_Cook]

So a stock fault means what was in there was not right spec.
I would trace out the associated comps to get an idea what it was doing.
Condsruction type of cap?
Volume would give , for the type of construction, assuming 400V rating
an idea of its capacity. Put 2 caps in there of 250V rating or 1 600V
rating and whatever nF will physically go in there.

[N_Cook]

On 21/07/2016 19:31, Gareth Magennis wrote:

Do barrel format SMD-R have a higher voltage rating,r for r, than slab
formats?

[mako...@yahoo.com]

> >
> > Any smart guesses what I should be putting in there? One end goes to
> > the three paralleled resistors which are very low ohmage and I guess
> > current sense at ground, the other goes to the first pin of the
> > transformer which is at high HT.
> >
>

another way to figure it our is this...

look up the data sheet for the active devices on the board.

often the data sheet will have schematics for example applications and often the UUT is pretty much exactly like the app notes.

M

[N_Cook]

Perhaps the supervisor IC, nothing of use on driver
http://datasheet.octopart.com/STW11NM80-STMicroelectronics-datasheet-24223.pdf

[Gareth Magennis]

wrote in message
news:24311c0a-ea31-4180...@googlegroups.com...

Cheers, I am being a bit lazy, but you do tend to learn a few things by
asking questions here as well :)

http://www.farnell.com/datasheets/87884.pdf?_ga=1.33261950.1327271115.1429123757

Page 2 - the cap is probably a small bypass cap not on the schematic on the
transformer HT winding to ground.



Thing is, this component looks like the achilles heel in this particular
design, unless duff components were sourced.
Else something else is blowing the component.



Gareth.

[N_Cook]

The Rs and C connected to CS pin3 of the supervisor?

http://www.onsemi.com/pub_link/Collateral/NCP1203-D.PDF

[Gareth Magennis]

Failure of this cap blew the PCB mounted mains fuse, rendering the unit dead
and requiring repair, so this is definitely a known issue.


Gareth.

[N_Cook]

This DVD apparently uses NCP1203, not downloaded the schematic though
http://www.go-gddq.com/upload/2009_07/09070211291778.pdf

[N_Cook]

Shinco DVD-2610 on Elektrotanya
assuming the SJK is an HV diode and 2x 4148 in the pic, then probably
much the same circuit

[sound....@btconnect.com]

Right, now I'm back in the lab, turns out this really is just a bypass cap, it's connected directly accross the main HT cap. I had at first assumed it was connected to the current sense circuit or thereabouts.

No bypass caps on any of the other circuits using this controller though, I guess a high voltage 0.1uF will do. (not SMD this time)


Thanks for the schematic links,


Gareth.

[N_Cook]

I wonder if it was a multi-layer cap in there with metal migration
growth leading to short.
Any other similar caps on there?

[Gareth Magennis]

"N_Cook" wrote in message news:nmsslu$fp3$1...@dont-email.me...

Not my photo, but this is a new PCB:
http://i852.photobucket.com/albums/ab83/audiosteve1/IMG_8676.jpg

My blown cap is the one in the middle of the bottom of the PCB, below the 3
parallel sense resistors and between FET TR200 and Tx T200.



Gareth.

[Gareth Magennis]

"Gareth Magennis" wrote in message news:0ttkz.867178$rI.8...@fx37.am4...

This small SMD cap is carrying rectified 240v mains voltage. Is that wise?


Gareth.

[N_Cook]

I suppose a 400V MLCC can suffer from metal migration as the numerous
50V notorious MLCC failures.
I've not looked for any manufacturers of 400V rated devils, I assume
they exist, should anyone be foolhardy to use them

[N_Cook]

So SMD 400V MLCC caps do exist (or did exist)
http://www.mouser.co.uk/ProductDetail/AVX/22258C224KAT9A/?qs=sGAEpiMZZMvsSlwiRhF8qtMAW1uaXrptEm0l1HszexY%3d


non-stocked, none on order, I wonder why

[javielectr...@gmail.com]

Hola, el condensador es de 2,2pf 2kv y poner un fusible de 3,15a y a funcionar.

[Hugo]

responding to
http://www.electrondepot.com/repair/icepower-200asc-amp-module-165648-.htm ,
Hugo wrote:
I have exactly the same issue with mine!

Did you happen to find the right part? Would love to know what to replace it
with.

Cheers

Hugo

[Gareth Magennis]

"Hugo" wrote in message news:2S%aA.334210$HF2.1...@fx41.iad...

I used a non SMD cap, read the entire thread.

Gareth.

[amdx]

Google translation.
Hi, the capacitor is 2.2pf 2kv and put a fuse of 3.15a and run.
Mikek

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[Hugo]

responding to
http://www.electrondepot.com/repair/icepower-200asc-amp-module-165648-.htm ,
Hugo wrote:

> javielectronicamateos wrote:
>
> El jueves, 21 de julio de 2016, 20:31:31 (UTC+2), Gareth Magennis
> escribi
>

Hi and thanks for info. I've been looking at this on and off for a long time!
With my very limited but growing (mostly iPhone and Mac logic board)
electronics knowledge I'm still rather unsure of what to do to fix the amp.

So avoid SMD - Use something like a single layer ceramic through hole?
600v to 2kv from looking through the thread
2.2pf or whatever pf can fit for component size?
A fuse 3.15amp so the cap doesn't keep blowing or maybe the 3 resistors in
series after the cap... - something leaded and I'm lost on voltage here, 250v?

perhaps this cap -
http://au.rs-online.com/web/p/ceramic-single-layer-capacitors/8312929/
with this fuse -
http://au.rs-online.com/web/p/non-resettable-wire-ended-fuses/8951678/

Any help would be super appreciated, I'm in dire need of BASS!!!

[Hugo]

responding to
http://www.electrondepot.com/repair/icepower-200asc-amp-module-165648-.htm ,
Hugo wrote:

Thanks for all the puzzle pieces folks, the bottom octave is back!!

High voltage cap, fuse in the right place.. all good!

Really appreciate the assistance ?

[mat...@gmail.com]

So bro can you let us know how did u fixed the unit, I have the same issue on the same module. Does 2.2PF 2kv SMD CAP really exist? I can only find the 50v type.

[mako...@yahoo.com]

On Tuesday, August 28, 2018 at 10:58:14 AM UTC-4, mat...@gmail.com wrote:
> So bro can you let us know how did u fixed the unit, I have the same issue on the same module. Does 2.2PF 2kv SMD CAP really exist? I can only find the 50v type.

I think the OP said he used a leaded cap for the replacement.
I don't know where the 2.2pF value came from but that seems too small to do anything useful in that circuit.

I'd put in a 1000 pf 1000V leaded cap and call it a day.

mark

[jurb...@gmail.com]

>"I'd put in a 1000 pf 1000V leaded cap and call it a day. "

Depends on where it is in the circuit, a whole nF ? That is alot at some frequencies.

[pit]

responding to
http://www.electrondepot.com/repair/icepower-200asc-amp-module-165648-.htm ,

pit wrote:
I repaired my amp with a 1000PF 1KV ceramic cap. Like Gareth, my main fuse
was blown and I also had to replace it.