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
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.
I've seen the FET switcher get leaky on these, but wasn't able to find a source for it...
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
messagenews:S_J_j.1477$ snipped-for-privacy@nlpi061.nbdc.sbc.com...
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.
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