Upgraded Vista 20P motherboard not recognizing older wireless sensors

Old 07-01-15, 07:41 PM
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Question Upgraded Vista 20P motherboard not recognizing older wireless sensors


I'm hoping someone can help with a weird problem I can't seem to find any information about. I'm trying to replace the motherboard in my Vista 20P panel since the "keyboard bus" is bad. I'm getting OC errors with any of the keypads connected to the motherboard even just through a short jumper wire.

The old board is ~14 years old and the main chip is Rev 4.0. The new board's main chip is Rev 10.3. Everything works with the new board except that some, but not all, of the older sensors (the ones that were originally installed ~14 years ago) just won't work with the new motherboard. I know the issue is not the wireless transmitters themselves or their batteries as I've tried known good batteries from the working sensors in the non-working sensors. I can also see strong red and green LEDs on the wireless receiver (a 5882-3ENH) when I try to enroll the sensors that won't work, so I'm confident the signal is getting to the motherboard. I even removed the 5882 receiver from the equation by disconnecting it at the motherboard and turning on the receiver on the 6150RF keypad I have hardwired but have not been using as a receiver until this test. I get the exact same results after enabling the receiver on the 6150RF. The sensors will also not work even if I manually enter the serial numbers. The issue seems to be on the motherboard somehow and not with the information getting to the motherboard.

I've even tried putting the old CPU into the new board...same results.

The only thing I can think of is that the motherboard itself (and not necessarily the CPU) is such a drastic upgrade that it's somehow incompatible with either the frequency range or something in the wireless protocols of the ~14 year-old sensor/transmitters. Has anyone ever heard of something like this? I have enough of the older sensors that I don't want to spend time and money to replace them all if there's an easier solution although that would probably fix the issue. Also, there are at least a few sensors that were installed with the system 14 years ago that are working with the new system, so it's not a 100% match in terms of only older sensors not working. Even the serial numbers of working and non-working sensors seem very close in terms of numeric range, so I don't think it's some type of issue with specific batches of old sensors...

Thanks in advance.

Old 07-01-15, 10:08 PM
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Hmmm...Oliver, you're the 3rd person this week that I've seen post a problem like this.

Check out RyanDL's thread on this forum. Sounds very similar to what you're experiencing. Right now I'm leaning toward diagnosing a bad batch of new Vista-20P panels.

It's possible that there's some transmission difference between old and new 5800 RF sensors, but the new panels are _supposed_ to support older stuff. After all, if the old transmitters work with older panels, that means the data is being transmitted: It's the panel's job is to interpret the data that comes through the RF Receiver. If the panel can't do that, then I say it's defective.
Old 07-02-15, 11:02 AM
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I'm having the same problem...

I was curious about you putting the old CPU into the new board... I checked all the other chips and no others have anything to do with programming or memory, except one chip to the upper left of the CPU. That is an EEPROM.

I suspect that would hold the programming information the customer programs in? And I suspect that would not work along with the new CPU as the memory locations would change with new features and so forth?

Anyway I should think you would need to replace the new chip with the old chip, then reset to factory defaults. Then re-enter everything and try it. However that would also lose all of your programming for the new chip!
Old 07-03-15, 10:31 AM
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Well, I'm sorry others are also seeing this but at least I'm not the only one having this problem..I hate when that happens! Hopefully it is just a bad batch of boards and returning the one I received will solve the problem. I was worried any new board would just do the same thing.

Bill, the CPU switch was really weird. I put it in both to see if it would affect the wireless problem and also to try to extract the field information for my account number. The problem I was having was that my ADT account number starts with an H, and there's no way to enter any letters other than B through F into Field 43. ADT was no help and said they could only send a tech out to program that field...

Anyway, switching CPUs, even after I had messed around with Field 43 trying to get something to work in there, seemed to work. And I do think the memory is stored off the chip, so the settings should have reflected all the changes I was trying to make while getting the new board and CPU to work. I took the opportunity to extract and write down all the original settings, so I don't need to rely on ADT to get things back to the way they were. There were some unusual issues when I had the older chip in, but I wasn't focused on fixing them. I noticed that the "Walk" test would chime the panel instead of chirp the bell for a few seconds...again, I wasn't focused on that and just tried to go back to the 10.3 chip and get the wireless to work. I have reset to factory defaults a few times just to start clean and see if I can get things to work...I may try another round of that using both chips to see if anything changes...
Old 07-03-15, 11:49 AM
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Most of the letters and numbers in an ADT account number are just administrative hash (they tell which receiver you are connecting to, so the programming tech knows which phone numbers to use). For the purpose of the monitoring account, only the last 4 digits count.

It sounds like you are putting a 20se chip into a 20p motherboard. I'm surprised that it works even well enough for you to access the programming.

The programming data is contained in the eeprom, not in the firmware...

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