Troubleshooting Circuitry in Old SD49225T-HN PTZ Cameras

guykuo

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Blessed is Kapton tape and all his works
 

guykuo

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[EDIT This post corrected to reflect current info regarding Alpha's image dimming with PTZ moves after its signal dropout issue was fixed]

No reboots for a couple days on camera Bravo.
Bravo is the PTZ that was rebooting about once/day and not storing its presets before I started work on it. The new battery helped with reboots and storing presets.
Since, it was already torn down, I went ahead and replaced the 220 uF 16 volt surface mount caps on the PTZ and POE boards. That gave me a chance to measure the old SMD caps out of circuit.

I could not get good in-circuit measurements of the old SMD capacitors, but kept them in good condition during removal.
I did not want to heat them up and alter their values with hot air so that method was not used. I tried my hot tweezers, but the ground planes soaked away heat too quickly for the tweezer to work.
Ended up using two soldering irons, one on each lead, to deliver enough heat but not cook the caps.

Old SMD 220 uF / 16 volts caps from PTZ board measured...
167 uF ESR 0.79
170 uF ESR 0.72
174 uF ESR 0.71

Single SMD 220 uF / 16 volts cap from POE board measured...
171 uF ESR 0.64

Those were not horrible values. For comparison, a new SMD 220 UF 16 volt caps measured around 184 uF ESR 0.64

Given that Bravo was mostly having reboot and preset storage issues, I'm not surprised its caps were only moderately degraded. I think its main issue was the memory battery being dead.

Cleaned up the glass face interior and buttoned up Bravo with fresh silica gel packs.

Deployed the recapped and re-batteried Bravo camera outdoors in place of camera Alpha.
We'll see if Bravo continues to resist rebooting when deployed out in the elements. Fingers crossed.

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Alpha is the one that formerly lost comms during fast PTZ moves. That issue was fixed by replacing the axial electrolytic caps on its PTZ and POE boards.
Post replacing its axial caps (but not its battery or SMD caps), Alpha no longer loses connection.

Alpha will get a new battery and SMD caps when I get a chance. I'm going to predict its memory battery is not completely dead because it still retains presets across power off/on cycles.
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Charlie is another PTZ that unreliably stores new presets. Charlie has oddly zeroed out statistics for days in service and times firmware upgraded. I'm predicting a very low but not dead memory battery.

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Delta, a very ill PTZ, suffers from multiple reboots / day and complete inability to retain presets across reboots. New preset positions are stored, but only until next reboot. It always defaults to some old, stored presets after reboots. I'm going to bet its memory battery is dead. Unfortunately, Charlie is a PITA to reach and will be worked on last.
 
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tibimakai

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When ptz moves and ir goes out, I would suspect weak power delivery. Measure the voltage, see if it drops.
 

guykuo

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This is interesting... Bravo seemed to be having the same IR loss with fast PTZ motions. The image was going near black and then coming back to normal after some fast PTZ moves. I could not understand how that symptom could move from Alpha to Bravo.

Then it dawned on me. I HAD fixed Alpha's signal dropout problem already on Alpha, but the darkening was something else. The signal dropout was complete loss of video feed for a few seconds, not just a darkening.

Watched with another camera while Bravo did some big PTZ moves that induced the image going black. Bravo's IR did NOT DIM nor go off!!!!
The dimming is, upon further investigation, an effect of the camera adjusting shutter speed within the range set in my manual exposure. Big PTZ moves were targeting different brightness scenes and that was the source of darkening. Lock the shutter speed and the dimming effect doesn't happen.

Alpha is not sick post its partial re-cap. :) I had fixed the its signal dropout issue but didn't recognize it was okay because I misinterpreted the image dimming as IR dropout.
 

guykuo

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Camera Bravo has gone 24 hours outdoors without a reboot. I think it is rehabilitated with its new capacitors and memory battery.

To sum my thoughts thus far....

Axial and SMD electrolytic capacitors have degraded over six years, but not severely. In camera Alpha, there was enough degradation to cause signal loss with PTZ motions. It signal loss occurs with PTZ motion, I would swap out all the electrolytics on PTZ and POE boards.

Memory battery is a component that that degrades. It is likely the root cause of inability to store presets across power off/on cycles. A dying memory battery somehow also causes spontaneous reboots, but I have no explanation as to mechanism. Perhaps the firmware is failing to write data, detecting the fault and rebooting for the exception.

If PTZ motion does not cause signal loss or reboot, it might be reasonable to change just the memory battery. The camera module is accessible via the camera's rear cover. One can measure the battery voltage without further disassembly. Power should be disconnected from camera, of course. If battery reads less than 2.7 volts, I would pull the camera module and replaced the battery. That taller, higher capacity battery linked by Tangent seems a good alternative to original.
.
It is impractical to change the battery without removing pulling the camera module. I tried and the battery immediately fell deep into housing. Just pull the module and life is a lot easier. Also, pulling the module lets you use a microscope for the work.
No need to remove board from camera module. The work can be done with it still attached to camera module.

Don't touch the lens unless you find it is soiled and needs cleaning. I use Formula MC-1 for my critical lens and filter cleaning, but that requires specific technique and is another topic.

Do check whether you need to cleaninside of glass window of camera sphere.

Remember to change to new silica packs before sealing the camera module.
 
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guykuo

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At some risk to home and limb, camera Delta was pulled down. Delta was a very ill camera that had multiple spontaneous reboots/day and could not remember presets across reboots.

Changed out its memory battery. Oddly, the old one was reading 2.6 volts - not horrible
Changed SMD and radial capacitor on its POE board

Delta now remembers presets across reboots. A couple days and we'll know if its spontaneous reboots are cured.
 

wittaj

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We gonna send our dying PTZs to you for repair LOL.
 

tibimakai

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I have the newer model, and last night I have noticed that constantly was zooming into a neighbor's house and goind back to preset #1. Non stop was doing this.
Even a soft reboot did not help. When I changed preset position, it stopped doing that.
What could be the problem?
 

wittaj

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I have the newer model, and last night I have noticed that constantly was zooming into a neighbor's house and goind back to preset #1. Non stop was doing this.
Even a soft reboot did not help. When I changed preset position, it stopped doing that.
What could be the problem?
Was she naked and @Arjun had control of your PTZ :lmao:
 

Jim_OS

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I keep my fingers crossed for you. ;)

A dying memory battery somehow also causes spontaneous reboots, but I have no explanation as to mechanism. Perhaps the firmware is failing to write data, detecting the fault and rebooting for the exception.
That's something I don't really understand either. I "only" have the problem with the reboots. Since the camera is currently being tested in my study, it does nothing other than display a live image/stream. All other functions such as MD, IVS etc. are not activated. That's why I don't understand why there are days when no reboot happens and then days when a reboot happens two or three times. If it is due to the battery that may be too weak, then these differences shouldn't actually occur. But we probably won't be able to find out the exact cause anyway. At least not me. :)

I'll have to think about at least trying to replace the battery. Well, let's see. Thank you for the research you have done so far. :thumb:
 

guykuo

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Alpha got its final touches today. New memory battery. Old was reading 1.5 volts. Its heat sink cage had to be removed to access its battery because in its revision the metal cage completely covered the battery. Also got new 220 ufd SMD and replaced the little radial cap on its POE power board. This is about as rehabbed as Alpha will get.

I’m going to install it in place of Charlie during a little weather break today. Charlie will get rehabbed at my leisure and be my spare PTZ
 

guykuo

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Delta is now 24 hours without spontaneous reboot. It had been months since it has gone this long without rebooting itself. Very encouraging.

Update...
Delta is solid x 30 hours
Alpha is also going well x 9 hours.
Bravo is over two days solid.

This is definitely looking good in terms of stabilizing the PTZ's. Plus, they get the benefit of having their window glass interior surfaces cleaned and I polished up the IR emitter plastic fronts while they were on the bench.
 
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guykuo

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Delta is still looking good.

Turned my attention to camera Charlie. Charlie had bad amnesia. Thinks he is only 1 week old and has had his firmware updated only once even though Charlie is much older and has undergone multiple firmware upgrades.
Charlie survived his capacitor and battery replacement procedure today. Took me just under 3 hours with all the disassembly, electronics rework, optical cleaning, and reassembly.
Not a time efficient process, but might save the camera.

Here are all the caps replaced on Charlie's POE power & PTZ drive boards. Of course, the battery was pulled from its camera module. Old one was reading 2.3 volts.

All the caps had degraded in capacity and ESR, except the Nichicon 470 uFd / 16v. The Nichicon was in surprisingly good shape when I measured it. Good quality caps do last longer.

replaced parts.jpg

I'm hopeful I can get some more life out of these old PTZ's, but still just a couple days into their field trial.
 
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javierfer

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Delta is still looking good.

Turned my attention to camera Charlie. Charlie had bad amnesia. Thinks he is only 1 week old and has had his firmware updated only once even though Charlie is much older and has undergone multiple firmware upgrades.
Charlie survived his capacitor and battery replacement procedure today. Took me just under 3 hours with all the disassembly, electronics rework, optical cleaning, and reassembly.
Not a time efficient process, but might save the camera.

Here are all the caps replaced on Charlie's POE power & PTZ drive boards. Of course, the battery was pulled from its camera module. Old one was reading 2.3 volts.

All the caps had degraded in capacity and ESR, except the Nichicon 470 uFd / 16v. The Nichicon was in surprisingly good shape when I measured it. Good quality caps do last longer.

View attachment 188211

I'm hopeful I can get some more life out of these old PTZ's, but still just a couple days into their field trial.
Thank you very much in advance for all this information, but since you are in a conversation about the hardware of this camera. My camera is dead and I want to revive it. My question is, what are the connection pins for the UART port? Is additional hardware necessary to connect to the UART of this camera other than USB-TTL?
 

guykuo

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Oh no. Delta did a reboot. Something deeper is wrong. It is better for sure but not cured.

Sorry, I have no info regarding the UART port on these PTZ's.
 

guykuo

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Delta is now acting very strangely. It will accept and store firmware updates, but is super unreliable about saving any other settings. Yes, I i did factory reset the camera.
Only some settings stick, while others don't survive across SOFT reboots. This is new behavior. I'm thinking its settings memory system is damaged beyond what can be explained by a bad memory battery.
Ugh! Of course on the camera that is scariest to dismount.

I think Charlie will have to take Delta's place once I verify Charlie is saving its settings properly.
 

guykuo

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Might be. Have no idea what type of memory or if it has a limited write endurance. I can't see going so far as pulling memory chip off its main board, but maybe a reflow of the board. Beyond that, it's nowhere worth my time.
 
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