[SOLVED] Oppo DV-980H No Sound Output - Page 1
Forum section: electronics / repair

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 02:38:31 am
content: I have an Oppo DV-980H DVD player and the video works perfectly. I get composite, component and HDMI output no problems, clear and all remote and on-screen functions work perfectly.However, the only problem is there is NO SOUND OUTPUT. I have tried HDMI, nothing. I have tried the 7.1 surround channel outputs, L/R and everything else I could plug into the back. No sound output at all. I have not tried the digital output though.The funny thing is, I am able to press "Mute" and adjust volume control on the DVD player. It even shows the on-screen display indicating what is going on. So the player must think everything is fine. I am wondering if there is a final analog output amplifier or something that is buggered up that is common to ALL OUTPUT JACKS. Or the DAC chip that drives the final output. Maybe a short on the output.Any ideas where to start?

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 02:41:51 am
content: I've added a few more photos, but I have to spread it across several posts as I am limited by size. Here is the main board and power supply board. I see no obvious physical damage. None of the capacitors looks to have a problem either.I've flipped over the main board, there is nothing on the other side. It is all one-sided.

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 02:45:55 am
content: Here is the area I suspect to have an issue. Lots of caps, what look like amplifying circuitry to drive the audio output. But whatever is causing the audio to fail is happening also in the HDMI audio signal. So I wonder if it is something to do with a digital audio chip and not on the analog side?I'm trying to look for the service manual. This is just a learning project for me.

author: nidlaX
author_rank: Frequent Contributor
timestamp: July 07, 2016, 02:46:23 am
content: Your theory about an analog amplifier problem doesn't hold up if you are unable to get sound over HDMI. If there is an audio codec chip that also handles digital decoding, that would be the place to start.

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 03:10:56 am
content: Quote from: nidlaX on July 07, 2016, 02:46:23 amThanks. Yes I was looking into the HDMI spec and I see it is digital PCM encoded. Therefore there must be something going wrong at an earlier stage, whatever is handling the audio for the entire system. The Oppo has many audio options, so perhaps a dedicated chip that is supposed to handle all of the audio processing has buggered up. I just updated the firmware as well, and no difference.[EDIT: I just looked at the board and notice the HDMI is linked directly to the Oppo MT13890P2 chip (MediaTek). I'm not seeing too much in the way of chips on the board. Seems everything is being done by the Oppo chip. The AmTek chip is a motor controller for the DVD. The Hynix is a memory chip. I'm not sure what the "980HUS-OA 94470" chip does. There is a small Cirrus chip heading off to all the caps and the 7.1 sound outputs.... Looks to be a DAC.]

author: nidlaX
author_rank: Frequent Contributor
timestamp: July 07, 2016, 03:53:46 am
content: There are many different variants of the MT1389. I would search among their datasheets for a version that approximately matches your chip and start debugging from there. You need to find one that is HDMI capable and has pinouts that match your HDMI connector layout.

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 04:48:21 pm
content: Thanks. I looked up some MT1389. The one used by the Oppo is a MT1389OP2. My suspicion is that the "OP2" is just a label that it was a custom run for Oppo players. As in "OP" for Oppo and maybe the 2nd version for their players (maybe an older player had MT1389OP1).Anyways, the chip appears to be doing almost everything in the system, including being responsible for all the audio and it leaves the chip to go to a DAC (for the sound system outputs) and also the HDMI separately (for digital). If I am not getting audio signals on either the components, it must be the chip itself. Either that, or there is something erroneously keeping a "mute" control on it, even though I can see the display mute and unmute when I click the button.I found some datasheets here, but nothing specifically for OP2 version:http://www.datasheetspdf.com/datasheet/MT1389.htmlNow to figure out what pins do what. I have to trace the leads from my HDMI and see where they connect to the chip. Also, I need to trace back the leads from the Cirrus chip (which I assume to be a DAC) and see where they connect to the chip, and look at the pinout descriptions on the variants of the MT1389 and see if things make sense.There is also this image which gives a sample use scenario, which I am trying to understand:(to get larger version, see here:http://pdf-datasheet.datasheet.netdna-cdn.com/pdfhtml/0255/738272/page1.png)Here is a full demo board schematic showing a full DVD player system:http://www.datasheetspdf.com/PDF/MT1389DE/738272/1(click Download PDF to get all 5 pages)

author: edy
author_rank: Super Contributor
timestamp: July 07, 2016, 05:11:35 pm
content: I also found this service manual for another player using the MT1389, maybe it will provide some clues:http://www.adelectronics.com.co/manuales/KXDV2008.pdfThere is also this one:http://fixmag.ru/download/1255207947_b_dk1830siru_ver2.00.pdfAnd this one:http://diagramas.diagramasde.com/otros/lg_ht303pd-d0.pdfThere seems to be a mute audio input to the MT1389. I wonder if somehow this is telling the chip to mute audio, even when the internal menus and controls are indicating a mute on/off. Anyways, I need to get back to my board and count the number of pins, and check where everything goes to see if any of these manuals are going to be of any help.

author: edy
author_rank: Super Contributor
timestamp: July 08, 2016, 01:14:39 am
content: and double...It wasn't the player at all. The TV that I had it plugged into for testing had something plugged into the phono jack which muted the speakers. I would have discovered that if I tried a different source, but I assumed it was the player... WHY? Because the person who gave it to me said there was a fault in it.Embarassing to admit I was such an idiot. Anyways, put back together, all is working perfectly again.

author: nidlaX
author_rank: Frequent Contributor
timestamp: July 08, 2016, 03:15:05 am
content: Quote from: edy on July 08, 2016, 01:14:39 amAnother example of a great lesson in troubleshooting: check the basics first! Make sure it's not user error! Start simple before you do stupid shit.