Fixing an Accenta/Optima Alarm Power Failure Troubleshooting

A long time ago our alarm box died and I thought it was time we diagnose an fix the issue.

DO NOT ATTEMPT TO COPY IF YOU DON’T KNOW WHAT YOU ARE DOING. CONTACT AN ELECTRICIAN OR ALARM INSTALLER.

We will be opening a delicate box with potentially live mains power and could cause damage to yourself or the panel.
Accenta Alarm Box with isolation switch above and LED light to the side.
Accenta Home Alarm Control Box (left)

As you can see, although our isolation switch is set to ‘ON’ the power light on the alarm box is not illuminated. This may be because,

  • The battery in the alarm has died.
  • A fuse in the alarm box has blown.
  • There is a fault with the incoming power to the alarm box.
  • There is a fault with the main board of the alarm box.

We know that there is no fault with the existing setup because the alarm used to work, so we can start to diagnose our four potential issues. I’ll also teach you how to reset your panel.

Opening the Panel

This step is the easiest but can be daunting for some. Remember, safety first. We will be dealing with a panel that may be receiving mains voltage.

Accenta / Optima alarm panel tamper switch

When we open the box, there is a small spring that pushes against the door, this little spring ensures that any burglars who attempt to open the panel, trigger the alarm. As our alarm is not working, nothing will happen but if the alarm does sound, then it may be a sign that your panel does not have a power issue, consider resetting your alarm. Unscrew the two front facing screws. Note that from here on out, experienced competent people should continue.

Accenta / Optima alarm control box with bottom section removed
Accenta / Optima alarm control box with bottom section removed

Now that we have taken the bottom section off completely, we need access to the top of the main board as well. There is a fuse we need to test in the top half of the alarm panel so we’re going to remove the top half as well, this bit is just as easy as the bottom half, but there is a speaker attached to the housing, we can remove the speaker by unscrewing the terminals or do what I did and simply let the top half dangle by its wires (lazy but effective).

Accenta / Optima alarm box completely opened exposing the components inside
Accenta / Optima alarm control box completely opened

Testing the External Power Supply to the Box

(If you are following along and have an Optima remote alarm panel, you may  need to find a box similar to mine, but it does not have any controls or lights - its also likely that your remote panel is not illuminated and the screen is off if it is a power issue.)
Power Light Not Illuminated

Firstly we need to test that the incoming power supply is working, this is where our AC Voltage tester comes in (fear not if you don’t have one but do have a voltmeter).

VoltAlert Wand

Using this wand we can see if there is power coming into the alarm. (If you don’t have one of these and are following along at home, you can set your voltmeter to AC or ṽ and place your black lead into the COM jack and red lead into the VOmA jack and when we open the alarm panel later put your test leads on the incoming supply chock block above the transformer, using the left brown and blue wire screws)

Place the wand near the incoming mains wire, if the wand sounds and flashes, congratulations. We have determined that the alarm panel is receiving power to its transformer.

VoltAlert want flashing and sounding with highligted testpoints for positive and negative terminals for voltmeter testing.

If there is no power, consider using a voltmeter as explained above to verify. If there is still definitely no power then a fuse may have blown in the isolation switch or the ring main RCD may have tripped, so consider diagnosing if they are the issue.

Testing the Alarm Battery

If you think that the Accenta / Optima alarm has stopped working due to a battery failure, we can test the battery by connecting test leads to the battery terminals on either side of the battery block or on the battery directly, you will need to turn off power to the alarm so that we don’t get the feed in voltage from the board. Do not put your voltmeter test leads in the red highlighted section. Make sure to set your voltmeter back to measuring DC voltage if you set it for AC earlier. Place your test leads on both screws on the green highlighted area.

Alarm Panel Power Block

If you don’t get a reading or a low reading (3V or less) then your alarm battery may have ran out because of power failure. If your battery reads ~12V then it is a good indicator that your alarm panel is faulty and will need to be replaced entirely, but I would suggest you check the fuses before doing so to verify.

Testing Fuses in the Accenta / Optima Alarm Box

If you have verified that the incoming power is working and your alarm battery is depleted then a fuse is a most likely cause of the alarm failing.

To test the fuses, you need to set your voltmeter to continuity mode and then test each side of the fuses contacts. Make sure the power is switched off before and during testing any fuses. If any are blown, replace like for like.

highlighted alarm panel shows red boxes highlighting fuse locations
Accenta / Optima alarm panel fuse locations

The fuses are as follows, from left to right; –

  • RKP or Remote Keypad
  • Internal Speaker
  • Bell / Strobe
  • Battery
  • Transformer

Resetting the Accenta / Optima Alarm Panel

To reset the alarm panel, remove power to the panel and short the SET output to the left PA input terminal. Then turn on the alarm and allow it to power up completely. After a few seconds, you can then switch off the alarm once again and remove the shorting wires. Make sure to replace any wires previously installed and then power up the unit again, the default 0123 code will now have been restored. Beware in doing this, you reset any zones, such as fire zones will have been reset.

Using Hashlib to Securely store user passwords and credentials.

What is hashing?

Hashing a password means that users cannot have their passwords compromised when a database engineer is reading cleartext in user databases (to a degree, the passwords could be decoded, but hashing them makes them illegible to someone who is not doing anything extensive). And also prevents hackers from reading passwords in plain text and can be compromised by collision attacks.

Additionally when hashing a password a salt may be added to the password, this prevents a database from being attacked by dictionary attacks.

Why Hash Passwords?

Storing User credentials in Plain Text is generally as bad practice as it allows anyone who reads the file (or computer) to see the password, username or any other credential without any sort of protection, In some cases it is against the law, such as PCI SSC Data Security Standards which handles debit and other card types. The solution to this is to Obfuscation in the form of hashing. Hashing a password makes a standard password seem completely random.

How hashing works

When a user signs up for a website or any other form that requires secure credentials, such as a password, username, email address or address, that user will fill in a form that will ask these credentials, then the web server will both hash and store the hash, the server will ‘throw away’ the original password and keep the hash. In a more secure environment the user may also be given a salt, this may be unique to the user or unique to the application (The user will not know the salt, the salt is owned by the server and will be kept secret.). When hashing both the password and salt will be combined and hashed.

How to hash a string in Python

This tutorial uses Hashlib as its hashing encoder which uses the ever bug free OpenSSL…

First we need to import hashlib and encode the input, then finally we need to check for a match.