Scantronic LP1 fuse lights when battery connected

[James3200]

I have an alarm that was installed in 1994. The board says 9434. Two weeks ago the smoke alarm went off (no smoke in house). Entered code, 15 minutes later went off again. Did this once more then, frustrated, disconnected the AC and DC to alarm. Last weekend I vacuumed the two smoke detectors (never did before). Tonight I first disconnected the speaker out wire from the number 6 spot on the board so as not to keep sounding our outdoor siren. When I connected AC, all functions seemed to work (except it showed low battery); however when I connected the battery a fuse (I think) on the board, glowed brightly. I then connected back the speaker out wire, this time the fuse glowed but dimmer. The number by this "fuse" is LP1. Is this supposed to glow? I never saw it glow when I changed the battery in year's past. Any / all comments appreciated.

 

[EightyTwo]

"9434" could be the date code - 1994, week 34...

I don't know of any Scantronic parts with this number. There was a 9454 5-zone panel once.

Whatever it is, the fuse shouldn't glow! In the UK, the fuses are 20mm x 5mm (about 3/4" by 3/16") glass fuses and, on the board, they are usually marked as FS1, FS2, etc. Indicators such as LEDs or lamps can be marked as LP1, LP2, etc.

If it is a fuse, pull it out and put a multimeter set on your highest DC current range across the fuse holder and see how much current it is drawing.

I think that you need to post pictures of the keypad and the control panel with the cover on and off...