Service manual for Denon DCD-720AE CD Player. - Page 1
Forum section: electronics / repair

author: elliottveares
author_rank: Contributor
timestamp: January 06, 2019, 08:09:52 pm
content: Hi All, I was unlucky enough to have my Denon DCD-720AE CD player die on me yesterday (Purchased in 2014, now out of warranty) when I plugged my iPhone into it where the power LED then suddenly started flashing red shortly after plugging my iPhone into the USB port and the smell of burnt electronics occurred. I immediately switched of my DCD-720AE CD player and unplugged my iPhone from the USB port.On powering up the unit a few minutes later whilst disconnected from everything including the amp, it strangely appeared to start playing automatically on power up (with the light still flashing red), however none of the controls on the front responded. Now it won't turn on at all and smells of burnt electrics. I have also checked the fuse in the UK plug what is ok.Have you heard of such a fault or failure before? I have never had an issue until now playing music from my iPhone to my Denon DCD-720AE.Anyone have any idea what may have gone wrong. I would appreciate if one could please obtain the service manual for the Denon DCD-720AE CD player for me, I can only find the service manual for the previous Denon DCD-710AE CD player.Regards: Elliott.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 07, 2019, 04:41:38 pm
content: Hi,Well other than Vbus pwr and ground, which, if shorted out, would cause pwr supply issues, that leaves Data lines +/- which connect directly to the USB MCU. Guessing that will be your issue, or part of it at least.Here's a link to the svc manual (you will need to register on the site).https://www.hifiengine.com/manual_library/denon/dcd-720ae.shtml

author: Chris56000
author_rank: Frequent Contributor
timestamp: January 07, 2019, 09:43:39 pm
content: Hi!I also have one f these Denon CD players I'm trying to repair but HiFi Engine blocked my account over a year ago and I cannot delete it to create a replacement account or download anything from them!I only downloaded one Service Manual from them and have never been able to get anything since, so how they can construe that as "abuse" is beyond me!Could someone either send me a copy of the DCD–720 Service Manual or an alternative link to a copy if they've been able to get it from HiFi Engine please?Chris Williams

author: elliottveares
author_rank: Contributor
timestamp: January 07, 2019, 10:13:04 pm
content: Not good so Far. Referencing page 57 of the service manual, when I have only the power PCB hooked up, component IC91 (voltage regulator fed from PCB sub transformer) has 3.3V out between pin 2 and 3. (Should be 3.9V, but I don't trust the accuracy of my £10 multi meter which the battery is getting low.)As soon as I hook up the main CD PCB to the power PCB, the voltage between pin 2 and 3 of IC91 drops to 1.2V.Is it worth trouble shooting further? If so what should I look for, IC51 on CD PCB? It is also worth noting it smells burnt around CAPs C827, C834, C836, C835 on the Power PCB.Regards: Elliott.

author: elliottveares
author_rank: Contributor
timestamp: January 07, 2019, 10:34:10 pm
content: Quote from: Chris56000 on January 07, 2019, 09:43:39 pmhttps://drive.google.com/file/d/1yVmGxdY4nupc_vWimIrLE6EBbn6C7YPh/view?usp=sharing

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 08, 2019, 09:30:12 pm
content: When a brand new 4K UHD DVD player that can play CDs, SACDs, etc., is available for roughly 100 USD, you need to ask yourself, is it worth my time, and the parts expense.

author: elliottveares
author_rank: Contributor
timestamp: January 16, 2019, 10:10:47 pm
content: Binned my Denon CD player in the end, I found a couple of small IC's in the end that had physically burnt out; one of which was on the main processor board.I have now bought a second hand Sony DVP-NS900V SACD player.