Troubleshooting Circuitry in Old SD49225T-HN PTZ Cameras
- Thread starter guykuo
- Start date
I have a question, have you managed or tried to connect to the uart port through a usb-ttl to the camera?
No. Camera is torn down and rather pointless to do anything more until a new memory battery is installed.
We will be waiting for information on any news that will help us solve the problem with those cameras. 
New memory batteries arrived from Digikey.
New one measured 2.45 volts out of package.
Recall that the torn down PTZ [Bravo] was brain dead without a battery in place. Without battery, the web interface would not appear, but it did ping at 192.168.1.108
It had been about a week without a memory battery on main logic board. Either there is a separate store for the firmware or the SRAM has amazing retention. I'm thinking more likely the former than the latter.
Soldered in new battery and confirmed voltage in circuit was 2.44 volts. So, didn't short out the cell soldering it in. Didn't even pull circuit board from the camera module. There is enough access to desolder/solder in cell with circuit board still attached to camera module.
Thank heavens for my stereo microscope. Those are inch markings on my work mat. Magnification made it simple to do the work, but it is probably doable without magnification, if you have young eyes.
Put PTZ back together and......
Web interface was fully active after boot up. PTZ position were storable and recalled after pulling power and restarting the camera.
Updated its firmware via normal web GUI without issue. (No TFTP nor UART machinations were needed)
Even imported a configuration file from another PTZ and the imported settings are active.
Stores and remembers new preset info across restarts.
FULL power IR illuminators and no glitches with PTZ motions. This particular camera did not have that issue, but is currently running with PTZ board from a camera that did have that issue.
So, it seems that little battery is absolutely vital to the camera's proper function.
Unfortunately, weather does not permit pulling one of other my Alzheimers afflicted SD49225T-HN's down for a battery replacement.
Will this fix the amnesia problem? This is quite promising.
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I have an SD49225T-HN that one morning suddenly got stuck rebooting it seems. It won't completely reboot, as it doesn't go through the initial movement of the camera that it does when powering up, but you can hear it click at regular intervals, see the lens zoom in/out, and if I ping it, it seems to respond to pings on 192.168.1.108 for several seconds, then goes to request timed out for several seconds, then goes to host not found, and it repeats that sequence roughly ever 1 minute and 16 seconds (although occasionally it takes longer until it responds again, but typically it follows that pattern).
guykuo
My question is if your camera had these same symptoms before changing the old battery?
Do you think that changing the battery can solve my problem in my case?
Similar symptoms. I think it is a reasonable thing to swap out the battery. Probably worth trying before doing anything more drastic.
Thanks for the information.
Does that mean that this camera in which you have now replaced the battery did not have the problem with the automatic reboots before - as is the case with my SD49225T-HN?
tangent
IPCT Contributor
- May 12, 2016
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- 3,973
It looks like there's a variant of this battery that's slightly taller (about 0.5mm) that has 50% more capacity, the MS421R. This should increase its lifespan.
Note though that this is a newer part an data about it's long term performance is lacking. It's merely harder to discharge a higher capacity battery as deeply.
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That may well help. Maybe give the battery a chance for a few more than six year.
After 24 hours camera running, the new battery reads 3.15 volts after camera is unplugged from POE+ power. That is a little different from the near zero I was reading from the original. Also, indicates the camera is charging the new battery.
I'm going to let this camera run for a few days and see if it does any reboots. To do that, I've pointed it at a non-stored aim point. When the camera reboots it tends to go to a preset aim point instead. In a couple days, I should know if there has been a reboot by either inspecting the camera aim and seeing if any motion was recorded. I guess the camera log should show something as well.
I'm overthinking detection of reboot and applying technology when something simpler will do. Going to put a piece of paint masking tape shaped with a thin middle section. The tape will bridge across the housing and rotating part of camera. If it reboots, the camera will break the thin section of tape when it does its stepper motor calibration movements. All I have to look for is whether the middle section of tape has been broken.
Reminds me of laying a littel piece of hair across objects you need to monitor for surreptitious movement.
Reminds me of laying a littel piece of hair across objects you need to monitor for surreptitious movement.
Yes, the easiest way to see it is under Log --> System
BTW: Last night I installed the old firmware version from 2019 again fore testing
Device Type DH-SD49225T-HN
System Version V2.800.0000000.4.R.R4.2510.9A.NR, Build Date: 2019-11-05
WEB Version V3.2.1.810588
ONVIF Version 18.12(V2.4.5.729857)
PTZ Version V3.02.93.RHNZ_170518_22722
but there was also a reboot with the old 2019 firmware this afternoon (see screenshot).
So for me it's neither the PoE power, nor the humidity, nor the firmware version and I hope that by replacing the battery, the reboot problems will go away for you. If so, I would also try replacing the battery, just because the camera is still too good to throw away.
Looking back through my POE board picts, I noticed there is actually a 220 uFd surface mount capacitor that I had not replaced. It is certainly large enough value to be important for keeping voltage stable with the POE under load.
I think my general approach will be to
• Replace all the main electrolytics (including that surface mount cap) on the POE power and PTZ drive boards.
This is will likely help with reboots and signal / IR illumination losses during PTZ movements.
• Replace the memory battery
This is will probably help with inability to store and recall presets. It might have an effect on reboots if the problem is due to invalid data during system operation.
Given the hassle of taking down and disassembly, It's probably not practical to do each type of repair step wise, but rather all at once. If those don't do the trick, it's into the bin.
I think my general approach will be to
• Replace all the main electrolytics (including that surface mount cap) on the POE power and PTZ drive boards.
This is will likely help with reboots and signal / IR illumination losses during PTZ movements.
• Replace the memory battery
This is will probably help with inability to store and recall presets. It might have an effect on reboots if the problem is due to invalid data during system operation.
Given the hassle of taking down and disassembly, It's probably not practical to do each type of repair step wise, but rather all at once. If those don't do the trick, it's into the bin.
If I were you, I would first wait and see whether changing the battery helped and not also replace the 220 uFd capacitor.
Yes - as you have already written - if you wanted to rule out all possible weak points and have already dismantled the camera, it certainly makes sense to replace the 220 uFd capacitor. I probably wouldn't or couldn't replace capacitors myself anyway because fine soldering work isn't necessarily my forte.
I would perhaps be confident enough to replace the battery with its soldered holder, but then probably nothing more.
Yes - as you have already written - if you wanted to rule out all possible weak points and have already dismantled the camera, it certainly makes sense to replace the 220 uFd capacitor. I probably wouldn't or couldn't replace capacitors myself anyway because fine soldering work isn't necessarily my forte.
I would perhaps be confident enough to replace the battery with its soldered holder, but then probably nothing more. 
tibimakai
Known around here
Great job!
I'm surprised, how come that battery is not a super capacitor? In a Fluke meter they use supercapacitors. I have just replaced one a few weeks ago, in a 189. It started to corrode, some start leaking after a few years, and can seriously mess up the board.
When you buy electrolytic capacitors, you should get some 105* ones. Maybe Panasonic FC series or similar. When I was repairing LCD TVs, I was told that those are one of the best to use in power supplies.
I'm surprised, how come that battery is not a super capacitor? In a Fluke meter they use supercapacitors. I have just replaced one a few weeks ago, in a 189. It started to corrode, some start leaking after a few years, and can seriously mess up the board.
When you buy electrolytic capacitors, you should get some 105* ones. Maybe Panasonic FC series or similar. When I was repairing LCD TVs, I was told that those are one of the best to use in power supplies.