Wanted a bit of fun for the kids over halloween but as usual, last minute. Got the smoke machine to work on drive movement but cannot get the spooky reminders to play out over the DoorStation.
After some checking I found a burnt PCB!! Kind of ties in with storms we had the other day and comfort going mental with a communications failure. Also lost the PSU to the CCTV system. Given the lack of time till halloween I like to attempt a temporaray repair.
Chui, what is U5? What are the traces around it? Anyone got a photo of a good PCB. Looks like another component next to U5 has blown to pieces. I think it is this that has smashed the corner of U5.
A bit more research has revealed that the chip is an audio amplifier that drives the speaker. The PCB that is burnt has cut off the ground supply to pin 6. I have remade this but needless to say I think it has met its maker.
Sorry, that board has been throughly killed. It must have been a powerful surge voltage due to lightning in the vicinity
A pity your halloween trick did not work out
Can your technicians check this out. I too have lost a door station, burn out look s like it is on the same point on the PCB, and I don\'t recall it breaking when there was an electrical storm.
More importantly, can you confirm that this would not happen to a keypad- to have the amount of burn on an outside station is one thing, but if there is a chance of this happening on an indoor station, I would be unhappy due to the fire risk.
Tis intresting because it is exactly the same chip and the same part of the chip that has blown. You can also see which way the unit was mounted, mine was on its side yours vertical.
In my install you could argue that outside influences could have contributed to its failure as I had it interfcaing to a separate doorphone. This meant that the internal speaker and mic were not used and the PCB was connected to external doorphone. As this also had a video camera in it and shared the same ground connection with the DVR that poped its PSU. I assumed it was down to storm damage.
I think I\'m right in saying that the chip is the amplifier for the loudspeaker. Were you using the internal speaker?
Please have these 2 door stations returned to us through the normal channels so we can analyse the cause of the problem
We believe this was caused by a short on one of the capacitors perhaps caused by moisture or water. This causes the power supply to short out, but we need to confirm on the individual case. The PCB is conformal coated according to military grade to prevent the ingestion of water so we need to study what failed there
This should not cause a fire risk as the plastic housings are ABS/PC which are fire-retardant. amd should not occur indoors
No I have not returned it but I do still have it. Where would you like it sent to, Andrew or Nigel?
I can also confirm that it is very unlikey to be water ingress in my case, as the unit was mounted in a roof void.
I have cleaned the PCB in an attempt to see the amount of damage and look to a repair. Not only has the chip blown but also the PCB has suffered sever scotching and tracks have been lost.
My unit was only a few months old, and unmodified, just using the internal speaker.
It is also located under a shelter, so is very unlikely to be exposed to rain, even though it is out doors. Could get condensation though
Happy to return it, just let me know where to. I would need to replace it with something to make the doorbell ring though first, At the moment that bit of the circuit still works. I\'m guessing that if I just get a new one, it could have the same fault?
