Diagnosing a possibly faulty HDMI plug

Thread Starter

Tp86

Joined Sep 13, 2023
41
I'm not sure if this place is the correct place to ask, sorry if not Back in 2021, we purchased a brand new Phillips HD monitor back in 2021 to use for our security surveillance system.

When we first installed the monitor the HDMI port on our network video recorder (NVR) would no longer accept any signals. It was as if the monitor somehow damaged the HDMI port on the NVR. So we sent the new monitor back to Philips to 'repair'

While the monitor was being repaired, we purchased a new NVR.

After we received the repaired monitor we plugged it into the new NVR. After about one week or less, the same thing happened to the HDMI port on the new NVR. It no longer took HDMI input from any monitor and HDMI cable.

So we told Philips and asked for a replacement but they refused and said their policy is they only repair monitors not replace them. So we gave it to them again to repair.

Now I have left the monitor sitting in the backroom for nearly 2 years and am too scared to connect it to anything. I was wondering, to try to compensate for some of the money we lost, is there any way I can actually diagnose the HDMI plug on the monitor so it can determine if it really is fixed? I don't want to spend hundreds on a really specific tool to test it though. I was just curious if anyone with some HDMI experience could let me know how I could possibly diagnose this myself? - My only idea was to purchase some sort of HDMI input device I could plug into the monitor and leave the monitor on for about a week to see if it damages the input device

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Tonyr1084

Joined Sep 24, 2015
7,777
There is no way I know of.

Last year I stressed and broke an HDMI cable. I THOUGHT I could simply peal the plastic off the connector and re-solder it. I learned something. An HDMI cable is far more complex than I thought.

What's not making sense to me is your statement that there's some signal or something coming from the monitor (TV Screen).
When we first installed the monitor the HDMI port on our network video recorder (NVR) would no longer accept any signals. It was as if the monitor somehow damaged the HDMI port on the NVR.
There shouldn't be anything coming from the monitor. I could be wrong. There MIGHT be some sort of "Ready" signal that can turn something on but I'm only guessing. All I can tell you is what I've already said - they're more complex than you might suspect.
 

dl324

Joined Mar 30, 2015
16,674
My only idea was to purchase some sort of HDMI input device I could plug into the monitor and leave the monitor on for about a week to see if it damages the input device
You could use it as a monitor on a Raspberry Pi. You can get a Pi Zero W 2 for about $15, plus shipping, and you'll need a mini-HDMI adapter. I think I've purchased the adapters from Vilros.
 

MisterBill2

Joined Jan 23, 2018
17,788
There may be two-way communication between the monitor and the device providing the program. So you really need more than two devices. In addition, I see also a VGA connector, try connecting that to a computer and see if it works.
AND HOW does a network recorder get an INPUT from a monitor, which is only a display device?? NONE of my recorder devices accept an input from a device that is intended to get a signal from an output from the recorder.
So I have a question: can the recorder play back to the monitor??
Of course the other fact is that the HDMI connector is the most cheaply built piece of garbage foisted on consumers of electronics in many years. It is the inferior response to the higher cost DVI connectors. So it is entirely possible that there is a failure. Do other connections on the device work??? In addition, some devices are not able to use the resolution of the devices they get connected to.
So do you have a different monitor for the recorder? Such as a composite video display??
 

bassbindevil

Joined Jan 23, 2014
818
LCD monitors are common enough now that it might be safer to just chuck it out. My current monitor was free from the side of the road, and it's 27" widescreen. Thrift stores have monitors from under $10, usually.

You could try buffering the HDMI signals through a splitter or switch, although those could cost more than a used monitor.
 

Thread Starter

Tp86

Joined Sep 13, 2023
41
What's not making sense to me is your statement that there's some signal or something coming from the monitor (TV Screen).
AND HOW does a network recorder get an INPUT from a monitor, which is only a display device?? NONE of my recorder devices accept an input from a device that is intended to get a signal from an output from the recorder.
I was thinking perhaps a signal was nor nessiserilly coming from the monitor, but instead, is it possible the monitor is shorting one of the pins which is causing damage to the HDMI port on the source device?

So I have a question: can the recorder play back to the monitor??
I believe NVR just works as a standard input devive providing the signal to the monitor.

Of course the other fact is that the HDMI connector is the most cheaply built piece of garbage foisted on consumers of electronics in many years. It is the inferior response to the higher cost DVI connectors. So it is entirely possible that there is a failure.
I too much prefer the DVI plug as it's way better quality. This monitor unfortunately doesn't have one but it has a VGA (analog) input.
Do other connections on the device work???
Yep, the VGA plug works. I dont know if it could potentially harm the source device it connects to though

So do you have a different monitor for the recorder? Such as a composite video display??
On the NVR's with broken HDMI ports, my brother said he hasn't tested them with a monitor other than the Phillips that we suspect may have caused the fault. We are very wary about connecting a new monitor to the damaged NVR in case it was actually the NVR that cause a fault inside the Phillips which in turn cause a fault in the second brand new NVR's HDMI port that we connected. There is so many unknowns

Currently we have a brand new monitor and brand new NVR at work cause we dont want to risk damaging the NVR again. They cost over A$1000.
 

Thread Starter

Tp86

Joined Sep 13, 2023
41
You could use it as a monitor on a Raspberry Pi. You can get a Pi Zero W 2 for about $15, plus shipping, and you'll need a mini-HDMI adapter. I think I've purchased the adapters from Vilros.
That's a very good idea. I had a look in my cupboard and I have an old set top box my dad bought with a HDMI plug on it so I am currently testing it. I think I just leave it on for several hours a day and see if anything stops sending or receiving input
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LCD monitors are common enough now that it might be safer to just chuck it out. My current monitor was free from the side of the road, and it's 27" widescreen. Thrift stores have monitors from under $10, usually.

You could try buffering the HDMI signals through a splitter or switch, although those could cost more than a used monitor.
Yeah it's tempting to just throw it away. I wanted to see if I could have a go at fixing it first or even determine if it actually is faulty

An intermediary-type device may work as a fuse type of device. Like you said they are expensive though just for that purpose. There are also HDMI surge protectors you can buy cheap but I don't know if they will protect each pin separately to it's spec voltage current with respect to the ground of the connector or it does something more basic
 

MisterBill2

Joined Jan 23, 2018
17,788
Consider that some monitors do communicate with the video output port on the computer. That is how some computers know the correct scan rate and resolution. I do not know the exact mechanism of that, it somehow relates to plug-and-play, which is an interesting function all on it's own.

In addition, if the scan resolution does not match what the monitor can display, it will not show anything. I experienced that problem with a video conference system, when the resolution would change between the setup mode and the conference mode.
So if the TS is able to access the menu on the monitor, check the available display resolution choices and compare those with what is delivered from the video recorder. THAT may be the entire cause of the problem. NOT ALL DEVICES ARE COMPATIBLE!! And some of them pretend they are much smarter than the folks who use them.

I suggest connecting the monitor to a different HDMI output device to see if it works there.
 
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Tonyr1084

Joined Sep 24, 2015
7,777
I was thinking perhaps a signal was nor nessiserilly coming from the monitor, but instead, is it possible the monitor is shorting one of the pins which is causing damage to the HDMI port on the source device?
If the monitor is shorting one of the pins then it would logically be an ever present short circuit. Some 25 years ago a friend got a computer but didn't know how to hook things up. They asked for my help. When I got there one of his kids tried to hook it up but bent one of the connector pins causing a short circuit. Check your connectors for bent pins. HDMI doesn't have pins but look inside. There could be a pin lifted and maybe folded over causing a short.

OR try a different HDMI cable.

I have flat screen TV's for secondary monitors. My MAC has an "Element" flat screen monitor, 35" diagonal connected as a secondary. My wife's Dell has the same TV for her secondary monitor. My security system has a smaller Toshiba TV as a monitor and my new MAC has a Samsung 55" flat screen TV in the woodshop. Why 55"? So I can make a drawing on the computer and project it to the 55. That way I can see the measurements from across the shop (550 sq. ft.) without having to run back to the computer screen just to see what the next measurement is.

If you have an extra HDMI cable then you MIGHT want to test that. I don't want to suggest experimentation with the possibility of damaging equipment again, so that's something you would have to decide for yourself. But certainly if you see damage inside the HDMI cable then at the very least you'll want to scrap that cable and use a new one. Just be sure the source of that cable is reputable.
 

MisterBill2

Joined Jan 23, 2018
17,788
The cable end of the HDMI connector does not have pins. It does have traces on a piece of PCB material, which for some of them is the cheapest paper-phenolic material possible. The pieces that contact those traces inside the recorder, are what is subject to damage So you will need a magnifier and a bright light to inspect for damaged connector blades.
The HDMI connector pair is a good example of designing for minimum cost with no regard to durability or reliability, at least the first two generations. Some of the more recent versions are made with better materials, at least the cable ends.
 

BobTPH

Joined Jun 5, 2013
8,661
The scenario of a monitor that connects to an output device and appears to be working, kills the device after a period of days seems unlikely to me. With two occurrences, one apparently immediate and the other after days, I think the best explanation is that the NVR is subject to failure and the monitor had nothing to do with it.
 

Thread Starter

Tp86

Joined Sep 13, 2023
41
Consider that some monitors do communicate with the video output port on the computer. That is how some computers know the correct scan rate and resolution. I do not know the exact mechanism of that, it somehow relates to plug-and-play, which is an interesting function all on it's own.

In addition, if the scan resolution does not match what the monitor can display, it will not show anything. I experienced that problem with a video conference system, when the resolution would change between the setup mode and the conference mode.
So if the TS is able to access the menu on the monitor, check the available display resolution choices and compare those with what is delivered from the video recorder. THAT may be the entire cause of the problem. NOT ALL DEVICES ARE COMPATIBLE!! And some of them pretend they are much smarter than the folks who use them.

I suggest connecting the monitor to a different HDMI output device to see if it works there.
That is very interesting. Thanks for the knowledge on this cause if gives me many reference points for testing. It could be that for some reason the old recorder or the monitor changed the resolution to a resolution that was not compatible with one of the 2 devices.
I have connected the monitor to a old set top box via HDMI and it definently works well on that. My brother said he kepts one of the 2 old recorders so I'll also do some testing on that

If the monitor is shorting one of the pins then it would logically be an ever present short circuit. Some 25 years ago a friend got a computer but didn't know how to hook things up. They asked for my help. When I got there one of his kids tried to hook it up but bent one of the connector pins causing a short circuit. Check your connectors for bent pins. HDMI doesn't have pins but look inside. There could be a pin lifted and maybe folded over causing a short.

OR try a different HDMI cable.

I have flat screen TV's for secondary monitors. My MAC has an "Element" flat screen monitor, 35" diagonal connected as a secondary. My wife's Dell has the same TV for her secondary monitor. My security system has a smaller Toshiba TV as a monitor and my new MAC has a Samsung 55" flat screen TV in the woodshop. Why 55"? So I can make a drawing on the computer and project it to the 55. That way I can see the measurements from across the shop (550 sq. ft.) without having to run back to the computer screen just to see what the next measurement is.

If you have an extra HDMI cable then you MIGHT want to test that. I don't want to suggest experimentation with the possibility of damaging equipment again, so that's something you would have to decide for yourself. But certainly if you see damage inside the HDMI cable then at the very least you'll want to scrap that cable and use a new one. Just be sure the source of that cable is reputable.
Thats true, my son is wrecked a couple of our charging cables as he doesnt understand you need to put them in carefully.
With the HDMI cable however, I believe the cable isnt the issue as we tried several cables. When i get the NVR back however I'll do some more test on that device as I have a feeling the contacts or the HDMI is damaged.
By the way thats a really cool idea putting the 55" screen in your workshop. Every workshop should have one

The cable end of the HDMI connector does not have pins. It does have traces on a piece of PCB material, which for some of them is the cheapest paper-phenolic material possible. The pieces that contact those traces inside the recorder, are what is subject to damage So you will need a magnifier and a bright light to inspect for damaged connector blades.
The HDMI connector pair is a good example of designing for minimum cost with no regard to durability or reliability, at least the first two generations. Some of the more recent versions are made with better materials, at least the cable ends.
I'll use a magnifying light to inspect the old NVR when I get it from my brother. In the future I am going to buy electronics that contain DVI input/output if I can find them. Unfortunately, most game consoles dont have them and even alot of monitors like the one we got dont have them.

The scenario of a monitor that connects to an output device and appears to be working, kills the device after a period of days seems unlikely to me. With two occurrences, one apparently immediate and the other after days, I think the best explanation is that the NVR is subject to failure and the monitor had nothing to do with it.
You could be right. We are just not sure why the second brand new NVR started recieving no signal from the HDMI port one week later

Out of curiosity, would an inline HDMI surge protector protect against out of spec tolerances to the HDMI modules? All our equipment is already surge protected against electrostatic lighting etc via surge protection border board, but I was wondering would a product like below actually protect against some sort of malfunction in the monitor causing over voltage or current?

Feature
1. Compliant with HDM1.4, HDCP.
2. Protect HDMI Input and Output for ESD and power surge.
3. Meet IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact).
4. Meet IEC 61000-4-4 (EFT) 40A (5/50ns).
5. Meet IEC 61000-4-5 5A (8/20µs).
6. Spark voltage/Current protection.
https://www.auselectronicsdirect.com.au/hdmi-in-line-surge-and-esd-protector
 

MisterBill2

Joined Jan 23, 2018
17,788
Now another question, which is how does the TS know that the recorder has failed?? Does it not play back to any other HDMI input device? What will make the most sense is verifying that the playback is not to any HDMI input display. It might be that the recorder is defaulting to a resolution the monitor is not able to display. And how do you know that it is not the network video recorder that is no longer recording? What sort of network?? And what is being recorded on? A CD, or a hard drive, or a DVD drive, or a memory stick? The TS is presuming I am totally familiar with their device, just the opposite is true. Not a clue about either the brand or the use. And there is at least one brand I would reject if it were free, delivered to my door, with free installation.
 

Thread Starter

Tp86

Joined Sep 13, 2023
41
Now another question, which is how does the TS know that the recorder has failed?? Does it not play back to any other HDMI input device? What will make the most sense is verifying that the playback is not to any HDMI input display. It might be that the recorder is defaulting to a resolution the monitor is not able to display. And how do you know that it is not the network video recorder that is no longer recording? What sort of network?? And what is being recorded on? A CD, or a hard drive, or a DVD drive, or a memory stick? The TS is presuming I am totally familiar with their device, just the opposite is true. Not a clue about either the brand or the use. And there is at least one brand I would reject if it were free, delivered to my door, with free installation.
Hi mate. I think you could be right in that the recorder may have been defaulting or trying to use for some reason a resolution that the monitor doesnt support. Or possiblely a 'pixel clock rate' that is unsupported by the monitor (I had that problem earlier this year with my graphics card on an older monitor.
I can't actually perform a test on the 2nd NVR that we suspected had the faulty hdmi plug (or module) as we dont have it. But my brother dropped in the first NVR which I initially thought he told me only had a faulty hdmi but in fact BobTPH is correct he said it completely seems to be failing.
I also verified this now at work by plugging it into a monitor via VGA and there is no output. When Im home ill plug in a sata HDD to see if it makes a difference. By the way I tested the voltage on the mainboard battery and it is only 0.6V. Do you know if these ones are supposed to charge themselves up while the recorder is on? I just wonder if the initial problem was a flat battery

Some pictures of first NVR
HDMI port looks ok
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48V DC input (power adapter looks under under no load reads 47.5V)
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Has no fan or even led to let you know its on! Not even a power switch
This is not the A$1000 one. Its about A$400-500
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On board battery reading 0.6V. Not sure if that is a problem. Unit was in use about 2 years before the fault occurred
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MisterBill2

Joined Jan 23, 2018
17,788
Certainly a flat (dead) battery can be the cause of a whole lot of problems, including "stone dead" in some devices, and "loss of setup information" in others. If the battery showed only 0.6 volts it was fairly dead. They show over 1.5 volts when not new but used a few months.
 

Tonyr1084

Joined Sep 24, 2015
7,777
A CR1220 is nominally 3 volts (as is seen on the battery itself). Their primary use as far as I've ever seen is to maintain either a clock or a memory. I've seen machines operate perfectly normal with the battery completely removed from circuit. I doubt yours is crucial to machine operation beyond holding settings.

As to your question whether they charge up - the answer is a stone hard "NO". They don't. They can last for many years before they need to be replaced in applications where they are there only to hold settings and memory. But as Bill said, your battery is dead. I'm assuming you tested its voltage out of the battery holder. Even if you tested it IN the holder, 0.6V is just not going to do anything for your circuitry in the NVR.
 

Thread Starter

Tp86

Joined Sep 13, 2023
41
Yep, you're both right. The battery is dead but it only holds the settings while the power is off I believe. As for the monitor, I've hooked it up to my PC and have been playing games on it and so far its not caused any damage which is good.
I opened up the NVR today and took the circuit board out on the bench and had a good look at it. I see an area of discoloration around the power input area. I have never seen this discoloration on a green pcb so my suspicion is one of the components over heated and caused it. My guess would be that tiny component in the middle of the discoloration but I have no clue. When a learn a bit more about circuits I'll have a go at diagnosing it. It has 48V going in, but I dont know where to look from there. Thanks for all the help guys regarding my monitor https://emojipedia.org/nerd-face
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MrAl

Joined Jun 17, 2014
11,263
I'm not sure if this place is the correct place to ask, sorry if not Back in 2021, we purchased a brand new Phillips HD monitor back in 2021 to use for our security surveillance system.

When we first installed the monitor the HDMI port on our network video recorder (NVR) would no longer accept any signals. It was as if the monitor somehow damaged the HDMI port on the NVR. So we sent the new monitor back to Philips to 'repair'

While the monitor was being repaired, we purchased a new NVR.

After we received the repaired monitor we plugged it into the new NVR. After about one week or less, the same thing happened to the HDMI port on the new NVR. It no longer took HDMI input from any monitor and HDMI cable.

So we told Philips and asked for a replacement but they refused and said their policy is they only repair monitors not replace them. So we gave it to them again to repair.

Now I have left the monitor sitting in the backroom for nearly 2 years and am too scared to connect it to anything. I was wondering, to try to compensate for some of the money we lost, is there any way I can actually diagnose the HDMI plug on the monitor so it can determine if it really is fixed? I don't want to spend hundreds on a really specific tool to test it though. I was just curious if anyone with some HDMI experience could let me know how I could possibly diagnose this myself? - My only idea was to purchase some sort of HDMI input device I could plug into the monitor and leave the monitor on for about a week to see if it damages the input device

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Hi,

A first thought is to use a vga to HDMI converter cable to connect rather than right to the HDMI connector, but this as well as other fixes like this still carry a risk.

That said, if you have a $1000 USD device that is being killed by a $100 device, the best bet is to buy another $100 device from a different manufacturer, even if it costs $200 USD. If the $1000 USD device still breaks, it's bound to be the $1000 device that is just going bad, and if it can not work with the monitor is was designed for, then it's a bad design. In that case, you'd be forced to go with another $1000 device from a different manufacturer.

Could it have something to do with the power connections or static electricity.
If it is plugged in and out a lot it may be static electricity and connections that are not protected well enough.
If the power connections for both devices come from different wall outlets, it could be a galvanic isolation problem, meaning one device gets a slightly different potential on the ground, or one of the grounds in one of the devices is not done right in the design.
To test for the second case, you could plug both devices into the same wall outlet but do not connect the cables. Then, connect an AC voltmeter to the two devices, one probe to one device ground, the other probe to the other device ground, and see if there is a potential difference measured. If you measure more than maybe 5 volts, connect a 10k resistor from one ground to the other and see if the potential goes to zero or much lower. If it does not go much lower there could be that problem.

Problems like this can be difficult to solve but the most certain fix is to buy new devices from a different manufacturer or at least a different model. I know this may sound a bit expensive, but the alternative is to keep blowing devices out.

My gut feeling is that there is a spike that appears on one pin caused by a small design flaw, which could stem from various reasons. A fix for this could be connecting a custom made connector set that has series resistors inside which reduce the current when a spike appears. This also carries quite a bit of risk though because the resistors have to be sized just right, and there are a lot of pins in an HDMI connector.

One almost sure fix comes to mind now though. If they make an HDMI galvanic isolation device you can insert that between the two device HDMI connectors. They make these for RS232, or at least they did at one time, so you can make voltage measurements with a voltmeter that uses a straight RS232 and not worry about blowing up your computer.
This will only work if there is not some innate design flaw with the $1000 device though.
 
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