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🛡Home Security => Problems and Troubleshooting => Topic started by: BlueScreenOfTOM on April 30, 2013, 08:19:20 PM

Title: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: BlueScreenOfTOM on April 30, 2013, 08:19:20 PM
Hi All,

I have a new issue that has started for me relatively recently.  It seems as though my SC1200's ability to receive RF signals becomes worse and worse over time, until I unplug the unit and remove the backup batteries to give it a full reboot.

The first signs of trouble started with an X10 light control remote pad (sorry, I don't remember the model number).  It is the one with the rubber buttons that allow you to send an ON or OFF signal to house code.  I have one of these in my basement that I use to control the lights, with the SC1200 upstairs as the RF receiver.  Range has never been an issue, but suddenly I was not able to get the remote control to work unless I was very close to the SC1200.  Then I began noticing when I'd walk through the door and I would not hear the door chime.  At first, I thought the battery was going dead in the DS12A door sensor, so I tried replacing the batteries.  No luck.  Then I decided to try some of the other door/window sensors, I noticed that only the sensors very close to the SC1200 were still working.  Out of desperation, I tried pulling the plug on the SC1200 and removing the backup batteries, letting it sit for a few minutes, then plugging it back in.  This seemed to fix the problem.  However, after a couple days, the RF reception began to fade again.  Once again, a reboot fixed the issue, but the problem keeps coming back.

I would think that maybe there was an RF interference issue, except that the problem goes away immediately after rebooting the SC1200.

Anyone seen this before?  Any suggestions?
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on May 01, 2013, 06:29:04 AM
I would have also thought an outside RF signal interfering.
Though the power reset fixing it would indicate a electronic hardware problem and I am leaning towards a hardware problem.

Maybe next time it happens. Just try the power pack disconnected from the AC outlet and letting it run for a short time on the back up batteries. As a test.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: BlueScreenOfTOM on July 07, 2013, 04:01:43 PM
I tried your suggestion and just unplugged the unit without removing the batteries to try resetting it.  This didn't work.  It is sort of hard to play around with this issue because it takes a few days for the issue to resurface.  It seems the only way to fix it is to unplug the unit and remove the batteries for at least 5 seconds.  Removing the batteries for just a moment doesn't seem to fix the problem.

Unfortunately this issue is a dealbreaker.  It seems to be occurring more and more often as time goes on.  I have to reset the system about once every two days now.  Twice in the last 2 weeks, I have inadvertently set the alarm off due to this issue.  I'm going to need to find a replacement SC1200, or replace the system entirely. 

If anyone has an SC1200 they don't want, drop me a message.  I just need the base unit.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 07, 2013, 04:15:15 PM
The symptoms make me think a capacitor (perhaps in the data-slicer circuit) is somehow charging up and raising the RF threshold. See http://davehouston.org/rf-noise.htm for a simplified description of how the data-slicer works. IOW, it seems to be a electronic problem, probably due to some component failure.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 07, 2013, 05:56:30 PM
I would also say it sounds like a hardware failure.
Are you still within the ninety day repair or exchange warranty?
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: BlueScreenOfTOM on July 09, 2013, 05:11:35 PM
I purchased the device back in September of last year, so I'm way out of the 90 warranty period, but still within 1 year.  Just to see what would happen, I sent an e-mail to X10 and they decided to make an exception and give me an RMA, which I think was pretty nice of them.  Hopefully the new one won't have the same problems.  I'll follow up here when I get it.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 09, 2013, 06:14:08 PM
Thanks for the update.
I am happy to hear they are giving you an RMA and an exchange.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: AntneR on July 19, 2013, 02:42:27 PM
I just purchased two "certified like new" systems where the controller SC1200 was certified but all the components are guaranteed brand new. After installing the system and moving the controller to a central location in my home I am experiencing the same issue as yourself. The furthest component from the base is only 30 feet. I installed 10 D/W sensors, 2 Motions, 4 Water Detectors and 2 remotes. I have an extra controller as a back up unit and now I'm glad I do. After clearing the LCD panel of any issues, I went to bed and woke up in the morning to 8 out of 10 of the zones flashing. I noticed when I opened one sensored door I did not hear a chime until I closed it and opened it again. Oddly enough, that zone was one of the zones flashing yet after the second opening it registered at the base unit. The zone number showed but it was not flashing anymore. I am going to try the 2nd SC1200 that I have and see if I experience the same issue. I would not be suprprised if my "certified" base is non-functional. The only other thought I had was that all my windows are covered with window film(I live in south florida) to reduce the heat coming into the house. I thought maybe that might be an issue with the RF signals even though it's not mentioned in the manual anywhere(I don't think). I will let you know if I am successful with the other SC1200.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 19, 2013, 03:09:58 PM
The sensors send a message around every 60 minutes to the console. To indicate they are functioning. If the message is not received in around four hours. The console shows a problem for that zone. That I believe is flashing the zone number and if you tried to arm the system. It would display Problem Zone.
When you opened and closed the zone. The console must have finally received a message and cleared the zone.

Let us know how the second console acts.
Which D/W Sensor was in your kit? DS10A or DS12A?
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 19, 2013, 03:38:57 PM
The only other thought I had was that all my windows are covered with window film(I live in south florida) to reduce the heat coming into the house. I thought maybe that might be an issue with the RF signals even though it's not mentioned in the manual anywhere(I don't think).
The film is not likely to cause problems. It, primarily, blocks infrared energy which is a much higher frequency and much shorter wavelength than the 310MHz RF used by X10.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: AntneR on July 23, 2013, 09:08:23 PM
Brian H and DHouston,
Let me start by saying you guys are awesome. I really appreciate you both trying to help me with my issues. I'm glad to hear that my window tint is no way reducing my RF reception. I put both consoles side by side and they both register the same 5 zones that are on that side of the house. They other 7 zones on the other side of the house are flashing. As I move the consoles into each of the rooms the zones disappear but the other zones start flashing. My home is a single story and 2000 sq. ft. Oddly enough the 4 water level detectors I installed(WD13A) set off the panic alarms no problem and 2 of them are on one side of the house and the other two are on the other side. One is in my bathroom where my zone #12 is and that window sensor shows flashing but the WLD sets off the panic no problem even when the console is way on the other side of the house. The D/W sensors I have are DS12A's. So everything seems to indicate a reception issue with the consoles. Even when I put the console in a central location I get some zones flashing after 4 hrs. I read some posts on adding length to the internal antenna or adding some kind of antenna to the D/W sensors. Adding length to the console antenna seems the easier of the two. If I knew for sure it would work I would try it, but I am supposed to get a tech call tomorrow from X10 and I don't want to do anything till I speak to them. The 2 remote controls seem to also work fine and distance doesn't seem to be an issue. I control my living room and my bedroom lights with the modules(no problems) and the are on opposite sides of my home. Reading some of these posts and it seems like a lot of customers are having the same issue. I will keep you posted after I speak to X10 Tech Support. Thx.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 23, 2013, 10:15:20 PM
From what you describe it does seem to be an RF reception issue.

This web page...
shows how to increase the signal from the sensors. It's easy to do and involves no modifications. Doing this to a couple of sensors might tell us whether we're on the right track.

Since X10 hasn't published a schematic of the console and I do not have one to examine, I'm reluctant to suggest modifying the console antenna without galvanic isolation for fear it may not be isolated from the 120V line. And, it voids your warranty.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dave w on July 24, 2013, 09:01:01 AM
I'm reluctant to suggest modifying the console antenna without galvanic isolation for fear it may not be isolated from the 120V line. And, it voids your warranty.
FWIW It uses a wall wart.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: AntneR on July 24, 2013, 02:50:58 PM
Just finished reading a post from "pseeker" from back on 2/29/12. He describes with text and photos how to modify the antenna. I know all you "Hero's" are aware of it because you all have comments about the post and most seem to agree that this mod fixes the issue. Again, I will wait to do anything till I've spoken with X10 Tech Support before I go voiding my warranty. I wish I would've been aware of this forum before I bought these kits because I probably would not have gotten them. Seems like a lot of folks have my same issue with reception. I am hopeful that I can get some resolution because I really want to keep the system. I will try the suggestions given to me and see if that helps for now. Thx.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 24, 2013, 03:16:15 PM
I'm reluctant to suggest modifying the console antenna without galvanic isolation for fear it may not be isolated from the 120V line. And, it voids your warranty.
FWIW It uses a wall wart.
I'm aware of that but suspect it has a more direct connection for PLC. When I asked him why he had not included PLC transmit capability, Paul Beam, the designer of the ESM1, told me it was not possible to push sufficient current through a 120VAC:12VAC transformer to transmit X10 to the powerline. So, until I see a schematic, I'm leery of making any antenna mod that is not galvanically isolated.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 24, 2013, 06:26:15 PM
I also have not seen any schematics.
This is from disassembling the XM19A wall wart power supply from my defective SC1200.
Has the X10 power line transmitter, zero crossing detector and DC supply in it.
The 4P4C phone handset style connector. Has Common, +12 volts, Zero Crossing signal to the SC1200 and power line transmitter keying signal from the SC1200 to the wall wart.
The power line transmitter output is through a tuned isolation transformer directly coupled to the AC input. The X10 power line signals do not go through the DC power supplies transformer.

I have used a 4P4C breakout board. To key the transmitter On with out the SC1200 connected. With a resistor between the +voltage and the transmitter keying signal.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 24, 2013, 07:23:32 PM
This is from disassembling the XM19A wall wart power supply from my defective SC1200.
Has the X10 power line transmitter, zero crossing detector and DC supply in it.
The 4P4C phone handset style connector. Has Common, +12 volts, Zero Crossing signal to the SC1200 and power line transmitter keying signal from the SC1200 to the wall wart.
The power line transmitter output is through a tuned isolation transformer directly coupled to the AC input. The X10 power line signals do not go through the DC power supplies transformer.
Is there a stepdown transformer for the +12V power supply? EDIT: The X10 knowledge base says it's a +8V supply.

From your description it might be similar to the CM15A which has an isolated power supply or it might be similar to a TW523 which does not have an isolated power supply. EDIT: My concern is because of X10's habit of using the AC line as electronic ground. This might put the antenna ground lead at 120V relative to earth ground. 

Is the PLC output from the console a gate signal (with a free running oscillator in the XM19A) or is it the actual 120kHz burst?
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 25, 2013, 06:01:58 AM
You are correct on the voltage. It is 8 volts not 12 volts.
The smaller ones for the MT12 and MT13 where 12 volts.
I will see if I can find more details on the circuitry.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: Brian H on July 27, 2013, 09:23:53 AM
Had a chance to open the XM19A power supply for the SC1200.
Zero Crossing to the consloe. Is the output side of a 4N35 Optocoupler.
Power line transmitter enable. Is the input side of a 4N35 Optocoupler.
AC Line input. Is two pins on the primary side of a transformer. Sticking through the back. To directly connect to the AC wall outlet.
Also each line pin has a wire to the PCB. That looks like it has a MOV across them and some caps to couple the power line transmitter to the line.
Secondary is a center taped winding. With the center tap connected to common of the cable to the SC1200.
Could not get the PCB out easily. So for now. There is more data to be traced out.
Title: Re: SC1200 reduced RF reception after time; needs periodic reboots?
Post by: dhouston on July 27, 2013, 09:58:13 AM
It appears to be similar to the CM15A AC interface circuitry. It's probably isolated.