Honeywell Galaxy G2 low voltage problem

[galaxy_owner]

hello all,



I have a Honeywell Galaxy G2-20 burglar installed in my home (about 9 years old).

Recently I got a Battery Miss fault showing on the keypad. So I replaced the battery in the main panel with a new one.

It was ok for a few days, then the fault re-occured. So I checked the main circuits in the main panel and found that the Aux and Battery Charging circuits are only at 4.0V DC (they should be around 13V DC according to my understanding). For reference I have checked incoming power 240V AC power supply and it is fine. I also checked the transformer output voltage and it is 17.9V AC (which I believe is also fine).

I tried disconnecting all detectors (just keeping the keypad and bell connected) and when I re-test the Aux and Battery Charging circuits the voltage only goes up slightly to around 4.3V DC. (I also have an zone expander board (Rio) on this system which I disconnected in this test).

This would lead me to the conclusion that there is something wrong with the PCB. Since this is an old alarm they don't make this version anymore. There are a few used ones around on ebay, but i'm not sure I want to try those.

Has anyone come across this type of issue before?

Is the PCB the most likely fault?

If I do indeed have to replace the PCB is there a new version that would work instead? If so, do I need a new zone expander also or will the old one work with the new PCB?

Any help would be much appreciated.

 

[buzzlightyear]

If and if the pc board has a fault the only
Aternative is to put other brand in considering you have the pirs.

 

[galaxy_owner]

If and if the pc board has a fault the only
Aternative is to put other brand in considering you have the pirs.

Thanks for the response buzzlightyear.

Do you think there is anything else I can test to try and further diagnose what could be causing the low voltage problem?

You mention that the only alternative is to put in another brand, are there no updated Honeywell versions of this type of Alarm system anymore?

 

[telectrix]

probably find it's a semiconductor. in the power supply. check the beast in the heat sink, top left and also the electroytic capacitor below it. check for any signs of dry joints or excessive heat on PCB in same area.

 

[galaxy_owner]

probably find it's a semiconductor. in the power supply. check the beast in the heat sink, top left and also the electroytic capacitor below it. check for any signs of dry joints or excessive heat on PCB in same area.

I took some pictures of the heat sink area. It's easy to see where the heat has affected the case and some cables above it. But can't see any visible damage to the PCB in that area.
The capacitor also looks ok (don't see any scorching or bulging).

 

[telectrix]

i reckon that semiconductor (thryristor?) is goosed. cpc farnell do suchbeasts for less than a pint of ale. worth a punt.

 

[galaxy_owner]

i reckon that semiconductor (thryristor?) is goosed. cpc farnell do suchbeasts for less than a pint of ale. worth a punt.

Do you mean this part (please see picture below):

 

[UNG]

Fuse F1 is the battery fuse have you checked this fuse isn't blown

 

[telectrix]

no.that's a capacitor and be a good idea to replaceit. the part i refer tois screwed onto that aluminium heat sink. it should get fairly warm in use.

 

[telectrix]

Fuse F1 is the battery fuse have you checked this fuse isn't blown

even if it is, he should still get13.6V from the PSU.

 

[galaxy_owner]

Fuse F1 is the battery fuse have you checked this fuse isn't blown

Yes, checked that first, it's working fine, thanks

 

[galaxy_owner]

no.that's a capacitor and be a good idea to replaceit. the part i refer tois screwed onto that aluminium heat sink. it should get fairly warm in use.

thanks telectrix, you mean this part below?

 

[telectrix]

thanks telectrix, you mean this part below?

yep.youmay have to do some searching to find out what device it is. try cpc farnell. a quick test would be to measure resistances between the 3 legs. diode tests with multimeter should show a couple of 0.6V.

 

[Avo Mk8]

As above ^^^^
Seems to be a LM317T voltage regulator

https://cpc.farnell.com/stmicroelectronics/lm317t/v-reg-adj-1-2-37v-to-220-3-317/dp/SC08260?st=lm317t

 

[Avo Mk8]

i reckon that semiconductor (thryristor?) is goosed. cpc farnell do suchbeasts for less than a pint of ale. worth a punt.

Certainly is less than a pint of ale at 28p

 

[DPG]

As above ^^^^
Seems to be a LM317T voltage regulator

https://cpc.farnell.com/stmicroelectronics/lm317t/v-reg-adj-1-2-37v-to-220-3-317/dp/SC08260?st=lm317t

Classic 3 terminal voltage regulator. Used many of those.

 

[galaxy_owner]

Hi all, just an update. I ordered the LM317T voltage regulator and also a replacement capacitor. I replaced the voltage regulator first. That has solved the low voltage to the Aux and Battery charging cable (both are now just above 13v DC). However, the keypad is not working, the screen is blank and every 15-20seconds it beeps, but the screen remains blank. I have charged the 7ah battery and tested it before powering up the alarm with it plugged in.

I then replaced the Capacitor on the PCB, but that doesn't make any difference. So now i'm stuck again. Not sure what else to try.

Note, before I replaced the voltage regulator I fully charged the battery and plugged it in and the alarm did work for a few hours (as it was being fully powered by the battery). So I know the battery is ok. So it's only after I replaced the voltage regulator that has led to this specific issue.

Any suggestions would be much appreciated.

Thanks

 

[DPG]

Going to be difficult diagnosing this remotely I think.

 

[buzzlightyear]

I then replaced the Capacitor on the PCB, but that doesn't make any difference. So now i'm stuck again. Not sure what else to try.

New system will solve it.

 

[UNG]

Have you checked that you have got power at the keypad