DVR having trouble starting

[Scruit 0]

What would make a DVR do this?

 

http://www.youtube.com/watch?v=u7JQiKAOLHg

 

 

It's a mobile DVR so it's 12v. The guage of the cable is good for 5 amps, the DVR needs 2. The voltage measure at the power connector is 11.99V AverDigi EB1304MOB. It does this when it's been sitting for a while not running - so first thing in the morning is worst. I'll power cycle it liek 10 or 15 times and then it will start up normally and work the rest of the day (even through more power cycles). Temp is about 50F.

 

I'm going to grab a spare car battery from the workshop and next time it does this I'll hook it directly to the car battery to see if it still does it - that would rule out insufficient voltage or current.

[cachecreekcctv 0]

Maybe it has a low voltage setting on the main DVR board, which might be causing it to go below , lets say 11vdc. An auto battery, 6 cells, is normally 13.2 vdc. Maybe , since this DVR was designed to be in an automotive application, there is a setting to keep it running, but only down to around 12vdc ?? What size of power wire are you using.? When you state " 5 amps", that to me, means around 18 gauge wire. Maybe the wire size is part of the problem, due to wire run length and the initial amp draw of the DVR.

[Scruit 0]

Maybe it has a low voltage setting on the main DVR board, which might be causing it to go below , lets say 11vdc. An auto battery, 6 cells, is normally 13.2 vdc. Maybe , since this DVR was designed to be in an automotive application, there is a setting to keep it running, but only down to around 12vdc ?? What size of power wire are you using.? When you state " 5 amps", that to me, means around 18 gauge wire. Maybe the wire size is part of the problem, due to wire run length and the initial amp draw of the DVR.

 

I'm using 16 guage which is good for 5 amps up to 15 feet. I'm tying into an existing 10amp circuit in the car so the 16 guage wire is only 3' long.

 

The DVR itself needs 2 amps to fire up and less than 1 as a steady state.

 

It look slike lack of current to me - but most times it works and on rare occasions it doesn't so I don't think it's quite as simple as wire guage.

 

I'm going to carry a multimeter and compare the voltage on a 'good' startup to the voltage on a 'bad' startup - maybe there's something there. I'll also get my battery tested at an auto parts place. Strange this problem just started when the cold weather set in.

[Kiwi 0]

It sounds to me like the DVR's internal switching power supply can't handle the startup current required by the hard disk, that's why it makes that noise.

 

If your 12V supply voltage at the DVR is within spec (whatever that may be) during this startup period then I would suggest trying a different brand of hard disk.

[cachecreekcctv 0]

I am wondering if this DVR should be on its' own set of batteries. Maybe the type used for UPS systems ? You would be able to tie this into the cars electrical, if you go to an RV shop. There are "dual battery" systems that serve this purpose for both boats and RV's. Just a thought.

[Scruit 0]

I am wondering if this DVR should be on its' own set of batteries. Maybe the type used for UPS systems ? You would be able to tie this into the cars electrical, if you go to an RV shop. There are "dual battery" systems that serve this purpose for both boats and RV's. Just a thought.

 

It should work find for what I'm doing. If I was running a winch or hughe sound system then I'd want a serepate battery - but we're talking about a 2amp drain here - that's not even a taillight bulb.

 

I'm going to replace the main power wiring with a 12 gauge cable. If that doesn't fix it then I'm just about to resort to a 12 gauge shotgun.

[mr.surveillance 0]

Try using 10 ga wire directly to the battery, (using a fuse of course).

The cold weather will result in a lower battery output and I am also assuming the DVR has internal voltage regulation which will also give a minimum drop of .8v for the semiconductor junctions. Most hard drives require 2 amps at 12 vdc + or - 10% to start. Most mobile equipment is designed to work from 12.5 to 13.8 vdc.

If your aux battery is tied to your charging system, battery isolator recommended, try starting the vehicle then firing up the DVR.

Good Luck and have a happy new year!

 

One way or another, you pay for what you get.

[Kiwi 0]

Again, clearly the DVR has a switching power supply (you can hear it) as every modern device does. There is no internal "voltage drop" to the hard disk, it's all regulated to whatever it needs to be.

 

If the incoming power is within spec, the only thing left is excessive inrush current to the HD. You could try a laptop drive, I'll bet that'll work just fine.

[Scruit 0]

Again, clearly the DVR has a switching power supply (you can hear it) as every modern device does. There is no internal "voltage drop" to the hard disk, it's all regulated to whatever it needs to be.

 

If the incoming power is within spec, the only thing left is excessive inrush current to the HD. You could try a laptop drive, I'll bet that'll work just fine.

 

I have the DVR on my workbench right now, hooked to a 12v 5Ah battery. I replaced all the power & ground wiring to/from the DVR itself with 14 gauge. I have run 14 tests so far, every time it starts up ok.

 

I attached my multimeter to measure the voltage between the + and - wires to the DVR.

 

 

When the power controller (external) starts up it sends 12.25 volts to the DVR (measured with the DVR power cable unplugged) If I plug the DVR in then the voltage startes at 11.75, drops to 11v while the fan and HD are spinning up, then back up to about 11.4 as a steady state.

 

The current test involves me tapping the vibration sensor to make the power controller turn on the DVR for 30 seconds, then letting it time out. I am using a video camera to record the multimeter display so I can see record any differences if it fails a test cycle.

 

So far it has passed 14 test cycles. I'm going to put the dvr in the garage overnight to get down to the same temp that it gets to in the car overnight.

 

 

Last time I saw a DVR refuse to power up like this I replaced the HD and it worked great - but that was failing 100% of the time - this is failing randomly about 1 in 20 bootups. When it fails I have to cycle the power about 4 or 5 times and it will start up ok and thereafter it is fine.

 

 

If I canot make it fail on the workbench then the next step is to test the car. Is the battery ok? Is the circuit & wiring that I'm tying into able to handle the current? Maybe I need to open up the car's fusebox and use an empty fuseholder / run a whole new 12 guage wire to the trunk to provide a dedicate wire able to handle 2amps.

[cachecreekcctv 0]

Sort of odd, as I took an Avermedia I had and ran it in my truck, just to see if it would work. I had no problems, but I was just testing it with 1 camera. Are the camera on the same circuit? A small 12vdc camera might be pulling an amp or so on startup, not sure, depending on the electronics/IR , etc. I ran my Avermedia EB1504 from the inside Power Supply and made my own startup cables. It did make a "groan" on startup, but I figured it was just "amping up" on startup. Only did mine for a day or so, and in nice Spring weather.

[Scruit 0]

Sort of odd, as I took an Avermedia I had and ran it in my truck, just to see if it would work. I had no problems, but I was just testing it with 1 camera. Are the camera on the same circuit? A small 12vdc camera might be pulling an amp or so on startup, not sure, depending on the electronics/IR , etc. I ran my Avermedia EB1504 from the inside Power Supply and made my own startup cables. It did make a "groan" on startup, but I figured it was just "amping up" on startup. Only did mine for a day or so, and in nice Spring weather.

 

 

I don't use the pass-thru power for the cameras, but the cameras and DVR are on the same circuit.

 

Ok, I ran the test on my workbench about 20-25 times - each time let it 'cool down' for 20 mins, then turned the power controller. Passed every time.

 

Test bench:

Battery: 12.7v (no load).

Power Controller output to DVR: 12.2v with no load 10.7v while the the DVR spins up, 11.2 steady state.

 

(there is a 0.5v loss due to a diode in the power controller)

 

 

In the car, headlights off, engine off:

Battery: 12.5v (no load)

Power Controller output: 12v no load, 10.5 while the DVR spins up, and 11v steady state.

 

In the car headlights ON, engine off:

Battery: 11.3v

Power controller output: 10.7v no load, 9.3v while the DVR spins up and 9.8v steady state.

 

Yes, I know, 9.3 V is VERY low, BUT - the DVR still starts up!! And when the engine is running, as 2v to all those readings. The failure that I've been seeing happens when the engine is running also! It's not a pure voltage issue.

 

 

I changed the 12 guage wires to 14 guage - for the short distance I'm going it should handle everything fine.

 

 

I am going to leave my multimeter conencted to the power controller voltage test port so I can watch the voltages while it fails. I'm also gonna see if it can handle 5amps and give me a good current reading too - that will answer a lot of questions.

[Scruit 0]

Got my multimeter inline with the power cable to the controller...

 

Power Controller OFF: 0.00A

Power Controller ON, 3 Cameras, GPS, Video Amp and Overlay board ON, DVR OFF: 0.61A

Power Controller ON, 3 Cameras, GPS, Video Amp and Overlay board ON, DVR spinning up: 3.60A

Power Controller ON, 3 Cameras, GPS, Video Amp and Overlay board ON, DVR steady state: 2.0A

 

Tested it a couple times, no failures during this testing.

[Kiwi 0]

You could measure the 12 VDC power pin at the hard disk for interest - it should be boosted and regulated from the input voltage to well within .5 V of 12 if the DVR was designed correctly.

 

I'm suspecting the most likely cause for this problem is that the disk platters inside the hard drive are getting a bit of condensation on their surface in the morning which makes the heads stick and therefore the drive is failing to start. I've seen this happen years ago when drives were "big" and I don't think any hard drives have ever been completely sealed - there is always a small vent and any internal desiccant would already be saturated.

[ak357 0]

Put on bench

 

take apart

 

buy Freeze spray

 

start troubleshooting

 

need some tips how to do it

pm me

[mr.surveillance 0]

How about hooking a relay to the power controller where the DVR is getting its power and have it switch the battery power directly to the DVR. This would eliminate the voltage drop from the controller.

Just a thought that passed through my brain.

 

One way or another, you pay for what you get.

[Scruit 0]

How about hooking a relay to the power controller where the DVR is getting its power and have it switch the battery power directly to the DVR. This would eliminate the voltage drop from the controller.

Just a thought that passed through my brain.

 

One way or another, you pay for what you get.

 

I see where you're going, but...

 

The voltage drop comes from a pair of diodes that I am using for the 'tank battery'. A small 12 battery that is capable of powering the DVR fro just a few minutes. During engine crank this battery bolsters the voltage coming from the car battery so the DVR doesn't crap out. If I used the power controller output just to flip a relay then I'd lose that feature. If I stalled the car at a red light then restarting it would be like yanking the power cable of a DVR right out of the wall socket.

 

 

See this page for discussion of the tank battery / wiring setup I am using.

http://www.mp3car.com/vbulletin/power-supplies/20359-battery-based-tank-circuit-tested.html