This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

On 25 mayo, 13:45, Brasto wrote:
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

look for a small value cap in the SMPS primary or near its IC. often
these are something like 1uF or 4.7UF and go bad preventing the psu
starting.

"b" wrote in message
...
On 25 mayo, 13:45, Brasto wrote:
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

look for a small value cap in the SMPS primary or near its IC. often
these are something like 1uF or 4.7UF and go bad preventing the psu
starting.

As well as the startup supply decoupling cap detailed above, check also the
startup resistor(s). Usually either a single resistor of 100k or so, or a
couple of lower values in series. Normally connects directly from the "+"
terminal of the main filter cap, to a pin on the controller IC (the same pin
as that small value cap connects to). Very common for these resistors to
fail open. Usual symptom is that the supply works fine until one day the
unit is unplugged, or there is a power failure, after which, it never
restarts.

Arfa

"Brasto" wrote in message
...
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

This model is a bit old for a PDF from Denon - I looked and it's not there
on the D&M FTP server.
In my experience the cost/effectiveness repair equation doesn't work out on
these. The DVD-1000 wasn't a great player to start with, and now there
aren't even major parts available for this model.

Mark Z.

"Arfa Daily" wrote in message
...

"b" wrote in message
...
On 25 mayo, 13:45, Brasto wrote:
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

look for a small value cap in the SMPS primary or near its IC. often
these are something like 1uF or 4.7UF and go bad preventing the psu
starting.

As well as the startup supply decoupling cap detailed above, check also
the startup resistor(s). Usually either a single resistor of 100k or so,
or a couple of lower values in series. Normally connects directly from the
"+" terminal of the main filter cap, to a pin on the controller IC (the
same pin as that small value cap connects to). Very common for these
resistors to fail open. Usual symptom is that the supply works fine until
one day the unit is unplugged, or there is a power failure, after which,
it never restarts.

Arfa


I've seen the FET switcher get leaky on these, but wasn't able to find a
source for it...

Mark Z.

"Mark D. Zacharias" wrote in message
...

"Brasto" wrote in message
...
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

This model is a bit old for a PDF from Denon - I looked and it's not there
on the D&M FTP server.
In my experience the cost/effectiveness repair equation doesn't work out
on these. The DVD-1000 wasn't a great player to start with, and now there
aren't even major parts available for this model.

Mark Z.

Gotta be worth just trying the 'usual suspects' first though, hasn't it ?
After that, I would agree that unless it's a labour of love for some reason,
it's not worth it. I had a Denon a few weeks ago (can't remember the model),
which like you, I couldn't get the switching FET for. The spares agents had
one with a similar number, but couldn't supply the exact one, and we
couldn't find data on either, so like you, I didn't proceed, as some
supplies can be very twitchy and sensitive about only having the correct
device in them ...

Arfa

On 27 mei, 10:26, "Arfa Daily" wrote:
"Mark D. Zacharias" wrote in om...





"Brasto" wrote in message
...
This DENON has a separate Powersupply board which is totally
inoperative. Yes it does charge the Big Reservoir ELCO upto 350VDC but
no further SMPS action noted,
I replaced as a shotgun approach the Q1 FET and the Optocoupler
SFH617.
Not having its schematic I have been unable to identify the FET
driving components.......
Is Mark still out there fighting the SPAM allowing me to get some
light on the most likely cause of failure?
TY
Brasto

This model is a bit old for a PDF from Denon - I looked and it's not there
on the D&M FTP server.
In my experience the cost/effectiveness repair equation doesn't work out
on these. The DVD-1000 wasn't a great player to start with, and now there
aren't even major parts available for this model.

Mark Z.

Gotta be worth just trying the 'usual suspects' first though, hasn't it ?
After that, I would agree that unless it's a labour of love for some reason,
it's not worth it. I had a Denon a few weeks ago (can't remember the model),
which like you, I couldn't get the switching FET for. The spares agents had
one with a similar number, but couldn't supply the exact one, and we
couldn't find data on either, so like you, I didn't proceed, as some
supplies can be very twitchy and sensitive about only having the correct
device in them ...

Arfa- Tekst uit oorspronkelijk bericht niet weergeven -

- Tekst uit oorspronkelijk bericht weergeven -

Mark & Arfa you probably both are right on the wasted time and efforts
if this was a commercial activity. Please donot worry about that as I
love to resurect dead electronic products where the official repair
stations have quoted astronomical prices to my friends and family.
Being retired gives me the freedom to spend unlimited energy (not
resources) to get things fixed.