Where to start troubleshooting? Older Keyence Camera Controller Video Card

Thread Starter

esp400

Joined Feb 27, 2019
13
Hi Everyone,

I have a Keyence CV-2100P camera controller that initially would not stay powered up in the cabinet of a machine when the camera cord or the video out cord were plugged in. After some troubleshooting we found a shorted ASi sub-bus conductor in the machine which uses vampire type connectors was grounding out on the chassis and putting 24VDC into the chassis so that if you read the meter at the DC power supply between the chassis and the DC return you would see 24VDC. Once we fixed that issue, we had no video feed to our monitor from this controller. We had a spare and swapped the video boards inside the unit and everything is working fine. I don't see anything visually on the board that has obvious damage. Where would I start troubleshooting this? What are typical components that would be the weakest link? I've included pictures of the front and back of the board. The video out is older RCA video connector for composite video. We've checked the battery voltage at 3VDC.

Any help you could provide would be greatly appreciated. Thanks!
 

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danadak

Joined Mar 10, 2018
3,625
Seems to be discoloration around inductor pins rear side of board.
Maybe MOSFET shorted out.

Other common failures electrolytic caps. There was a series of tantalums' some
years ago that had internal shorts problems.

Any discoloration around a component, or "leakage" around a cap signs of
problems.


Regards, Dana.
 

Thread Starter

esp400

Joined Feb 27, 2019
13
Hi esp400.. which connectors on the board were connected to the faulty camera / equipment?
Only the yellow video out RCA style connector. This is what I've initially considered replacing. This board is connected and powered from another board through the cream colored board to board connector. The camera was connected on a different board.
 

pmd34

Joined Feb 22, 2014
402
Ah Ok...
Hmm... i wasn't able to see where the traces go from the connector.. its covered with the black sheet.

I seem most of the gubbins on the board is for rs232 communications.

I would try and trace the tracks from the RCA connector and see what they go to on the board. They should at some point go into an IC, that has probably been damaged with the voltage.. try and identify it, and find a data sheet for it.

Have a look to see if it has the correct power supply voltages on it, and see if there are signals going in / out of it from the computer and camera.

Post an update if you can find the tracks or IC and I can look into it further.
 

Thread Starter

esp400

Joined Feb 27, 2019
13
Ah Ok...
Hmm... i wasn't able to see where the traces go from the connector.. its covered with the black sheet.

I seem most of the gubbins on the board is for rs232 communications.

I would try and trace the tracks from the RCA connector and see what they go to on the board. They should at some point go into an IC, that has probably been damaged with the voltage.. try and identify it, and find a data sheet for it.

Have a look to see if it has the correct power supply voltages on it, and see if there are signals going in / out of it from the computer and camera.

Post an update if you can find the tracks or IC and I can look into it further.
The black connector above the RCA out is for RS-232 which is not in use. I will trace the circuit and see what I can find. Thank you!
 

Thread Starter

esp400

Joined Feb 27, 2019
13
Here's a shot of the front of the board with the trace. If you zoom a bit, you shouldn't have a problem seeing the color traces. Component C810 I would assume is a capacitor. I can't find much on the internet other than one hit at Mouser on the specs printed on it (doesn't look similar in appearance though). Component R811 between the coil and the cap has a 150 printed on it. The '1' is hard to see. Component A803 is an IC which the video feed is fed from (again an assumption). It has an 'A12' printed on it (very hard to see) and the 'A' looks like an upside down 'V'. The coil has continuity through both sides. Terminal 1 of the coil (indicated in yellow) has continuity with a lot of the holes in the board. Let me know how I can clarify anything further. I haven't found anything of use really.
 

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pmd34

Joined Feb 22, 2014
402
Hi esp400, it looks like that little area of PCB around the capacitors and the small IC A803 could be a DC-DC converter.. it has an inductor (L807) and capacitors etc. My first suspicion would be IC A803, as if a capacitor gets upset, it usually demonstrates in a big way by spitting out chunks!

If you have the possibility I would look to see if there is a voltage across C811 C813 and the big can capacitor. One or more of these will be the input voltage to the DC-DC and one will be the output (if it is!)

Ideally you need to try and find out what IC 803 is, but its always a bit of a detective job with SMD components.. and it helps knowing what you have before you can tell what you have! It looks like a "sot-23-6" but check the size from pics on the net. Then do a search for "sot-25-6 marking XXXX" and see if anything comes up.. if not add "switching regulator".

I suppose the mystery is where does the video signal go.. I guess this must be the blue wire, but there is nothing obvious on the PCB for processing that kind of signal!
 

Thread Starter

esp400

Joined Feb 27, 2019
13
So the ICA803 is prob boosting the voltage from 5V chip voltage to 24VDC output? Should I expect to see 24VDC on the capacitors that are towards the output jack then?

I agree the capacitors look fine. That was one of the first things I looked for. No domed tops or breaks or leaking anything.

I put SOT-23-6 on google and compared dimensions from a drawing to the ICA803. Everything looks ok except for 1 measurement is a little big. I've attached a photo. From one leg on one side to the other side is about .5mm long. I guess it could be solder. I can't honestly tell where it ends.

I searched for SOT-23-6 marking and I found a document for the switching regulator but the markings do not match.

https://4donline.ihs.com/images/VipMasterIC/IC/ANIT/ANITS00021/ANITS00021-1.pdf

I will get the voltage of the capacitors and report back.
 

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pmd34

Joined Feb 22, 2014
402
Hmm I had no luck tracing the marking either.. Looking at the close up of the component I see that 2 of the pins are actually connected together, so it may not be a DC-DC...
I still dont see anything that looks like it is processing a video signal, which is strange, and also.. is it a multylayer board? Many of the tracks seem to disappear?

1V seems a bit weak to do anything useful with.

Not to be outdone... as we dont know what has failed yet.. maybe checking voltages between the working board and the faulty one might give a clue.
It looks like the supply voltage goes to each section of the board through 2 resistors R858 R860 for example. I guess that the one that goes to the large copper area will be 0V and the other +V.. see how those compare.

You could also try the voltages across the bigger capacitors, the ones which have polarity marked on them with a line, as these are likely to be some sort of supply capacitors.
 

Thread Starter

esp400

Joined Feb 27, 2019
13
R858 is +3VDC with respect to R860 on the input to that section of the board. I also checked C812 and it also has +3VDC across it. I found another IC catalog which shows many components (about 10) which have 'A12' markings. I guess my question is: Which component (IC) is typically found in a CVBS output circuit. Honestly, I haven't the foggiest what that signal looks like. I'm assuming that it's 3VDC in but what is supposed to show up on the output side after that coil.
 

Thread Starter

esp400

Joined Feb 27, 2019
13
According to this gentleman, it looks as though the output on a CVBS is around 1V

http://www.labguysworld.com/VideoCookBook_005.htm

Which prompted me to start looking for the IC he references at the end of the article. I found this IC on the middle board. Analog Devices ADV7177KS which indeed has a CVBS output. I'm looking up power specs now and will try and check the voltage and see if the chip powers up.
 

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pmd34

Joined Feb 22, 2014
402
How do those voltages compare with the the working board?
I guess R870 R869 are also 3V?
Seems a bit strange, I would expect 3.3V or higher.
If you find a marking that matches you need to look at the data sheet for the compenent, check if it IS the same, then have a look at how to wire up the IC and see if there is any relation.
Incidentally do the LEDs at the top of the board light up in the way the working one does?
Is there any chance of getting a schematic for the board from the manufacturers?
 

pmd34

Joined Feb 22, 2014
402
Oh well spotted! I didnt see that IC! There is a recommended layout on page 34.. should have 5V going to the chip at a few points it seems!
Maybe the mysterious A12 is an amplifier...
 

Thread Starter

esp400

Joined Feb 27, 2019
13
However, the fix was board specific. Meaning I changed the board and it worked again and this guy lives on a different board so it must be a component other than the IC that creates the signal
 

Thread Starter

esp400

Joined Feb 27, 2019
13
The boards are stacked together with board to board connectors and there is only around 1/2" space between and I do not have test leads small enough to get onto one pin. I have .032" safety wire wound around my test leads and it's just too big. I'm going to search for something that I can use to test the voltage with. I have an auto ranging meter (Fluke T5-1000). I'm pretty certain it should see 3.3VDC though. I will borrow a meter to compare.

I suspect the A12 chip is an amp. I still don't know what to replace it with though.

LED's work the same. The power comes on so clearly the board is powered up.

Chip is powered with 3.35VDC. I used two separate GND's (21 &42). I only have access to one Vaa pin (pin 1). Looks like page 10 references 3.3V timing specifications. I'm guessing that the chip is good.

I'm going to email the manufacturer. See if I can get any info on the suspected amp.
 
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Thread Starter

esp400

Joined Feb 27, 2019
13
Hmm.. OK.. but it is this board that is faulty... everything works when you replace this board alone?
Yes. The board fixed the problem. Keyence called me yesterday and told me that they were not going to help. Any ideas?
 
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