Smoked panasonic

[Neil Harrington]

Hi

I'm trying to repair a panasonic SVHS VCR model NV-HS830 ( european
model but guess other units would have a similar switcher design) I have
tracked the problem to a S/C zener on the secondary which has caused one of
the power mosfets to go s/c as well . So far so good.. except that the
resistor marked R1105 on the HV side is so burned I do not trust the
readings I am getting and do not want to fry more mosfets trying to guess...

I have tried panasonic who put me onto their service manual company who
really helpfully told me that the manual is out of print ,... great the
units less than three years old !

Can any one help ideally with a schematic or just the value.. ?? cheers
folks

 

[Mr Bungle]

Try replacing all the Caps rated at 1000uf, very common for them to go.
also the 330uf are suspect too. Any caps the are close to the output
of the secondary winding of the transformer. they get hit with the high
frequency
output from the transformer, and fail after a few years.
use military grade replacements 105deg Cenetegrade rated.


"Neil Harrington" <neilr@harringtonn.freeserve.co.uk> wrote in message
news:FOQ_b.10660$h44.1135304@stones.force9.net...

Hi

I'm trying to repair a panasonic SVHS VCR model NV-HS830 ( european
model but guess other units would have a similar switcher design) I
have
tracked the problem to a S/C zener on the secondary which has caused one
of
the power mosfets to go s/c as well . So far so good.. except that the
resistor marked R1105 on the HV side is so burned I do not trust the
readings I am getting and do not want to fry more mosfets trying to
guess...

I have tried panasonic who put me onto their service manual company who
really helpfully told me that the manual is out of print ,... great the
units less than three years old !

Can any one help ideally with a schematic or just the value.. ?? cheers
folks

 

[Neil Harrington]

Thanks Mr Bungle

All caps are OK .. checked ESR's first ! just need the value of the burned
resistor .. thanks again !


"Mr Bungle" <Mr Bungle@aol.com> wrote in message
news:lv4%b.20924$M8.1469851@news4.srv.hcvlny.cv.net...

Try replacing all the Caps rated at 1000uf, very common for them to go.
also the 330uf are suspect too. Any caps the are close to the output
of the secondary winding of the transformer. they get hit with the high
frequency
output from the transformer, and fail after a few years.
use military grade replacements 105deg Cenetegrade rated.


"Neil Harrington" <neilr@harringtonn.freeserve.co.uk> wrote in message
news:FOQ_b.10660$h44.1135304@stones.force9.net...
Hi

I'm trying to repair a panasonic SVHS VCR model NV-HS830 ( european
model but guess other units would have a similar switcher design) I
have
tracked the problem to a S/C zener on the secondary which has caused one
of
the power mosfets to go s/c as well . So far so good.. except that the
resistor marked R1105 on the HV side is so burned I do not trust the
readings I am getting and do not want to fry more mosfets trying to
guess...

I have tried panasonic who put me onto their service manual company who
really helpfully told me that the manual is out of print ,... great the
units less than three years old !

Can any one help ideally with a schematic or just the value.. ??
cheers
folks

 

[Geo]

On Tue, 24 Feb 2004 23:08:58 -0000, "Neil Harrington"
<neilr@harringtonn.freeserve.co.uk> wrote:

NV-HS830

some listed for $10 at
http://www.electronicsrepair.net/scemes.html

nothing found at http://www.mauritron.co.uk


Geo