Kenwood DNX6990HD service manual needed

[tom66]

Re: Kenwood DNX6990HD service manual needed

What are you powering the unit from?

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

From my 30V/5A adjustable power supply. It consumes ~1.7 A.


By the way, all three HK receivers are sold. Picked up another refurbished Onkyo, but this time is a TX-NR515.
I'm thinking about that maybe I should pick up some of these or even TX-NR616 from Ebay.

[tom66]

Re: Kenwood DNX6990HD service manual needed

You powering it @ 14.4V? Or at least 13.8V?

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

Yes.

[tom66]

Re: Kenwood DNX6990HD service manual needed

Hmm, check all the voltages along the amp chip. Especially the outputs supposed to be 7.1V each. No communication on this chip.

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

The problem is that when it starts up, it won't stay on for long and then shuts off and then I'm not getting almost any voltage, except the IC positive supply.
At the power supply IC I'm also getting the BU5V(4.94V), which I don't know which one is that.
It's almost as in a TV, when you have a 2 seconds to black and then only the standby voltage is present. It's very similar situation. I have to wait a long time when I can boot it up again.
I will have to re-solder the amp IC and take some measurements. It's too hot to work in the garage(96 F).

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I had to give the DNX570HD to the Kenwood repair service and they found the MI COM IC defective. W10-0853-08, can be found at pacparts for $50.
Found the removed IC(M16C/R5F3651NDFC) a lot cheaper at Digikey:
http://www.digikey.com/product-detai...3U0-ND/2299682

[tom66]

Re: Kenwood DNX6990HD service manual needed

That is a microcontroller, it has a set program, you need the program for the micro to work.

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I was thinking about that. So I guess pacparts sells one with the program on it.
The 570HD is working well now.
I still have to get a DVD drive($158+S&H+tax) for the 6990HD and I don't know if the old drive's parameters will work with the new drive. If not, then I will have to give it to Kenwood to do a calibration on it. Luckily they are pretty close to me.

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I'm wondering about these guys, which part are they replacing to fix the rebooting issue?
http://www.salectronics.com/shopexd.asp?id=1745
It seems, like it would be a cheap fix. If they had to replace a board or something of that nature, the repair it would be much more expensive.
What would cause, a reboot of these units, corrupted EEPROM?
There are so many broken units out there, it would be nice to find a fix for these issue.
In one of the forums, somebody claimed that he had two burned USB sticks and the whole USB line it was dead. It could be a 5V regulator?

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I have done some more testing with the unit and I have noticed that if the car is running, then it's fine.
As soon as I turn off the car, it starts rebooting.
It seems like it doesn't like lower voltages. What could that be? There it could be a bad voltage regulator?

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I have connected it directly to the battery, so I guess when the engine is running, the battery gets charged and the receiver works fine.
When the engine stops, the battery it's not charged anymore and I guess the voltage drops toward 12V, which it seems like it's not enough for this receiver.
I will power it up again from my lab power supply and drop the voltage to see when it's starts acting up.
In the service manual(not exactly for the same receiver, but it should be pretty close), there are some charts with all the IC pin voltages, which I could compare with, but I would like to narrow it down as much as possible.
Any help would be appreciated.

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

This could be an EEPROM fault too, or it's a voltage issue, what do you think?
Somebody on Ebay, can fix this issue for $99. I'm wondering what they are doing to them?
In some forums, people are saying that Kenwood replaces the ROM chip.

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I have sent it out to that shop on Ebay and they have replaced a Toshiba 2GB memory and now it's working great.
I have just purchased another one from Ebay, for $172 shipped with all the accessories.
The part number is Toshiba TC58NVG1S3ETA10.
Do you think, that this part can be replaced by me? Does a memory chip needs any software? The pin's pitch is very small, I'm not even sure, if I'm able to do it myself.

[elettr]

Re: Kenwood DNX6990HD service manual needed

Hi, I just signed up. How did it fix the problem? Did you figure out if you were just wound up the new flash to fix the car stereo?

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I have done one myself. I have purchased the pre programmed nand(~$65 pacparts.com, or kenwoodparts) and I have replaced it myself. It did not start right away. By touching the touchscreen, it started up. I don't know the reason for this, but that is how I have managed to turn it on.
You may be fine, by just reprogramming the same nand, or a new one, I don't know.
I have asked Flashcat and they said, that this nand would work with it.

[javierulo]

Re: Kenwood DNX6990HD service manual needed

hi i need service manual kenwood dnx6990hd or the part number ic31 is dc-dc converter

[tibimakai]

Re: Kenwood DNX6990HD service manual needed

I'm at work right now. I have it on DVD. I have purchased it, from pacparts.com.

[army_wang]

Re: Kenwood DNX6990HD service manual needed

Kenwood DNX6980 service manua

[army_wang]

Re: Kenwood DNX6990HD service manual needed

Kenwood DNX6980 service manual