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From: jango2 on 27 Nov 2009 10:40

Thanks for respnding Bill :)

Brute force
hammer n punch?
i have clearance between back cover n shield
5 mm displacement? Wht if I cut another hole through?
smd filter caps on board too?
no schematics for inverter available, no marking on caps

How does the black patch and foil work anyways
How do i word this innocently to Hitachi to get them to hep?

From: PlainBill47 on 27 Nov 2009 12:22
On Fri, 27 Nov 2009 07:40:20 -0800 (PST), jango2
<crow_slapper(a)yahoo.co.uk> wrote:

>
>Thanks for respnding Bill :)
>
>Brute force
>hammer n punch?
Well, I was thinking of something like a sheet metal nibbler (drill
hole in sheet metal, tip of nibbler goes through, nibble out opening
of any desired size ande shape). In this case, 'brute force' meant a
solution which avoided the sensitivity to metal without actually
repairing the design defect.

>i have clearance between back cover n shield
>5 mm displacement? Wht if I cut another hole through?
>smd filter caps on board too?
There is a hole in the inner shield, I'm guessing it's about 5 cm x 7
cm. I would cut a rectangular hole 6 cm x 8 cm in the perforated
shield. Next, build a shallow rectangular pan 6 cm x 8 cm by 5 mm
deep with a 5 mm outer rim. Finally, attach the pan over the opening
you cut.

>no schematics for inverter available, no marking on caps
>
>How does the black patch and foil work anyways

I don't have a clue.

>How do i word this innocently to Hitachi to get them to hep?
Why be innocent? I would start out assertive - "What is the reference
number for the service note, change order, or repair kit to solve the
inverter shut down problem on a 37LD9000 TV?"

PlainBill
From: Franc Zabkar on 27 Nov 2009 15:10
On Wed, 25 Nov 2009 22:10:44 -0800 (PST), jango2
<crow_slapper(a)yahoo.co.uk> put finger to keyboard and composed:

>Hitachi 37LD9000 Inverter tripping, green led on, sound ok, no
>picture.
>Pics contain textual narration.
>
>http://i596.photobucket.com/albums/tt46/jango_2/Image1.jpg
>http://i596.photobucket.com/albums/tt46/jango_2/Image2.jpg
>http://i596.photobucket.com/albums/tt46/jango_2/Image3.jpg
>http://i596.photobucket.com/albums/tt46/jango_2/Image4.jpg
>http://i596.photobucket.com/albums/tt46/jango_2/Image5.jpg
>http://i596.photobucket.com/albums/tt46/jango_2/Image6.jpg
> Jango

The datasheet for the Rohm BD9890FV inverter controller states that "a
strong electromagnetic field may cause the IC to malfunction":

http://www.rohm.com/products/databook/video/pdf/bd9890fv-e.pdf

However, the above warning may be a general one, as it occurs
alongside other general warnings including "mounting failures, such as
misdirection or miscounts, may harm the device".

What if you tried shielding the BD9890FV IC inside a metal box ???

Or what about a grounded metal plate above it, and a plate below it on
the underside of the PCB?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
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