I am on vacation in Florida and I am surfing my surv cameras over the internet. I was trying to review some previous footage but my system locked up as the DVR was playing back footage. When I rebooted and tried to log back into the DVR, I couldn't.

So I get my cousin to go to the house and unplug the unit and restart it. It beeps when he unplugs it and now it won't start back up again? I;ve been trying to remotely debug it with him with no luck.

There is power at the wall outlet for sure. I got him to open the unit up and unplug all the HDDs to see if it will even start up (i.e. fan spinning) and nothing. It's completely dead.

Anyone have any idea what could be wrong? Is there a fuse or something that could have blown? ESD damage? Anything?

Does your DVR have the separate 19 volt power cord?

See if the light comes on on the transformer.

It also may be the extension cord that goes to the wall, and to the power supply. Sometimes they have to be checked that they are plugged in, and may need to be pushed in a little deeper.

Push the power button? (I know he did, but I had to say it).

The next step involves a multimeter. (Some DVRs die because of a wall switch gets turned off, and the wall socket is dead until the wall switch is turned back on).

You will need to verify wall outlet power, power pack voltage, and power right as it connects to the PC board.

The rest requires knowledge of electronics. Do you have some bad diodes?

Are you putting the proper voltage out ot the regulators?

If it is completely dead as you say then it has to be in the main power "chain", and we just need to fing the bad link.

yes it has the 19V (I guess) brick. It used to run hot all the time I remember.

Does it have a light on the brick? If so, I can get my cousin to check that.

I am sure the AC outlet has power. I got him to plug in another device into the same outlet and it works.

He tried multiple times on two different days. I'm sure he's got the right button and he's tried to push it quickly and then just sit there and hold it for 30 seconds with nothing happening.

I have extensive electronics knowledge and have access to state of the art scopes and probes. But I have never tried to debug a DVR. When I get back I will take a look at it. If you have a schematic for this device that would pretty much get me to where I need to be. Otherwise I value any other information that you can give me. Thanks!

If you have worked with electronics then you will not need a schematic as the power supply is a basic power supply.

I have a feeling that there is a simple explanation, and that if you were on site you would have the DVR running in 5 seconds. The other person I am assuming does not have troubleshooting experience, and this may be a confusing to this person.

Worse case scenerio:

Check this chip for output: U32 3.3 volts. If shorted to ground then replace diode 6. Pin 3 is the output.

http://scorpiontheater.com/Documents/AV ... werReg.pdf

If you do not have power then it gets tricky.

Thanks for all the tips. I might need help later on.

Yes you are right, my cousin doesn't understand electronics.

I will report back when I return and take a look at it.

Thanks again.

*edit* what's the likelihood that there's some sort of ESD damage? Are these kinds of devices prone to this kind of damage?

We always demand some kind of line filtration. A good UPS with line filtration will keep a lot of the nails out of the coffin!

I have a high quality UPS that the DVR is connected to so I'm not really worried too much about power surges. I'm more worried about human body discharge or something like that.

I got my cousin to go in again and look for an LED on the brick and he couldn't find one. I walked him through a simple check of the output of the brick with a voltmeter and if he did it right, it appears the brick is dead. No output voltage.

What is the output specs of the brick?

*edit* - BTW, my previous DVR was another AVTECH one that got zapped by a lightening strike. It didn't die, but the picture was all shakey after the strike. A lot of other devices in the house completely kicked the bucket. My insurance company didn't believe me when I filed the claim, so I used the footage that I recorded to show them. Big storm, lots of rain, picture is clear. Then big lightening flash and the picture is all wavey and distorted. Adjuster couldn't deny it after that.

DC 19 Volts





Awesome!! I love hearing that!!

5A good enough?

Is the input jack the same as say a laptop 19 V power supply? I have a 19V 5A DC supply from a laptop available. Can I just get him to try that and see if it fires up?

Remember that the DVR draws 42 watts. You should have one rated 90 to 120 watts.

A proper replacement will be needed if the DVR is under warranty. Using a different power supply will void the warranty.

Dell power supplys have been used on the DVRs. I do not know whether they had to cut off the power tip, or not.

5 amp should work, but you are on your own with using it.

So I got my cousin to try the new power brick and it powered up no problem. So it's the brick that died.

Now about that warranty...I bought the unit direct from AVTECH via a friend in Taiwan that called them up and ordered it. He then shipped it to me. This was much more economical compared to the local saleman. Even if I have a warranty, I can't even get tech support from them so I doubt they'll send me a new power brick. I don't even remember how long ago it was that I got it, so it may be the warranty has expired (how long of a warranty do they have anyways?). And I don't want to have to go through the hassle of trying to get it via Taiwan and bother my buddy again.

So I guess I'm going to have to stick with an aftermarket brick unless I can get an OEM one for cheap. Honestly I wonder if it's a bad thing to stick with the one I got now, because I'm fairly certain that the stock power brick is undersized, atleast for whatever combination I'm using. I have three big PATA drives in there and even just idling (not recording) the brick gets pretty hot. If I had to guess, what happened is the unit was stuck in playback and record mode for quite a long time (when I lost connection with it) and it overloaded the brick eventually. That's only a guess, but the only thing that makes sense.

Anyhow, thanks a lot for your advice Scorpion, you do a great service to this community.

Your observation about the drives killing your brick may be right, or at least it is a thought.

Due to the procedure that you used to get your DVR then you probably got it below what most vendors can buy it for to resell at retail so then you are ahead of the game, and you can "afford" to lose the warranty aspect.

Due to your background in electronics then I support you in your "factory modifications".

I only throw in the "scare the devil out of you" for those who have no background, or experience with electronics that just try "anything", and then ZAP! OH! OH!

It probably would not hurt to add another fan to the mix now that you have a larger power supply to help in powering the drives, and the extra cooling fans. I would hate to see the chips get over heated.


Did you have to modifiy the power tip? What brick did you use? If you have a model number that would be great, and a link for the specs, and where you bought it. I would like to add that to my "list" of replacement parts for others who may need the info.

I haven't been back to look at it but one of my colleagues found one kicking around. It's from a laptop. I'll post back the details when I get back and see it. The tip is slightly bigger and is loose, I know that much, but it's tight enough to get the unit up and running. It's been running fine for a day now.

BTW, I've already modded the unit by putting heatsinks on all the chips that got hot enough to warrant it. I did this when I first installed the unit.

My previous unit (AVC777) had loud fans over a couple of the hot ICs and made a lot of noise. It was a bad solution in my opinion as those fans were going to die at some point. On this unit I left all the fans in there but put as big a heatsink as possible on all the ICs that were getting hot.

19V times 5 amps = 95 watts. Should handle it with no problem.
Dave

So I can confirm that indeed it was the brick that died. I found a bunch of different bricks that do 19V with 5A or higher current but none of them matches perfectly. The DC side tip is a little different. But no biggie, lopped off the end of the old one and soldered it onto the new one. I am now running with a 19V 7.9A brick. It's an AC BEL API3AD25. I also hooked up a wattmeter on the AC side just to see what the pull from the wall is, and during boot up I saw a peak of 71W for second or two. That's at the wall so the DC draw is about 57W (assuming 80% conversion and that my cheap ass wattmeter is accurate 8D ). Despite the possibility for error I'm pretty sure that's more than the stock brick can deliver over a long period of time. Luckily this is only during boot up. During normal operation I'm seeing about 52W from the wall during recording so assuming 80% efficiency again the DC draw is about 42W, right on with what Scorpion mentioned. This is with 3 HDDs installed.

So now that I have the mondo power brick, I wonder what's the highest power HDDs that I can install. I want to maximize the storage and use the biggest drives I can find, but usually they draw more current. Anyone know how much current the internals can take? I don't think I will have a problem feeding it power from the outside anymore. The old brick would be fairly hot all the time. This one is at ambient temp. Not even warm to the touch.