The barrel assembly might be more difficult to assemble than shown in the “First Checkup” video on our academy page due to manufacturing tolerances.

When inserting the barrel, pull the charging handle back, so you have a clear view of the nozzle of the gun, which is where the hopup chamber will be located once assembled.

Please ensure that the nozzle and hopup chamber are aligned properly when pushing the barrel assembly further inside, you can correct this by pushing against the nozzle if the hopup chamber is getting stuck on it.

Please ensure that you are using the recommended weight of BBs and trying different hopup settings when measuring, as this affects the power output.

Whenever you notice the power dropping, clean the inner barrel and hopup bucking, as there might be dirt or lubricant inside.

If pre-cocking is enabled on your gun, make sure to shoot a few times on the full-auto setting before storing the gun, as pre-cocking is disabled on this setting.
Storing it with the spring pre-cocked can lead to the spring wearing down and losing power over time. Depending on the spring, a power loss of up to 20% can occur due to this.

If the power loss is higher than this, there may be a problem with the air seal components. Especially if the gun has been used for over a year without a service, cleaning and re-lubrication of the gearbox assembly might be required.

1 long beep (1 sec): The ETU is unable to complete a full shot cycle.

This could be caused by different issues, such as:

• The motor is stuck and cannot move/the gears are locked up
• The voltage of the battery is too low
• The sector gear was not detected by the ETU
• etc.

4 beeps (keeps beeping): The battery has reached critically low voltage.

If you hear this error, unplug the current battery immediately.
You can then plug in a new battery to keep playing, ensure to charge the used one and do not store it before recharging to storage capacity.

1 short beep (0.3 sec): The ETU is overheating and locks up for a few seconds.

Let the motor cool down a bit before using the gun again.
This error should only occur if shooting multiple magazines worth of shots in quick succession.

Thoroughly clean your inner barrel and bucking, as this is most likely the cause of the problem.

If this does not resolve the issue, check if any parts of your hopup chamber are missing or damaged, and if the hopup bucking is aligned properly.

Check if the battery works and is fully charged.

Follow the “Disassembly” video on our SSR77 academy page and check if either of the motor connector cables are disconnected. If that is the case, plug them back in and check the functionality again.

If this does not help, please follow the “Disassembly” video further and check the ETU and the wiring for any visual damage or disconnected wires.

First check if the magazine is feeding the BBs up properly or if they are getting stuck in the feeding tube of the magazine. If this is the case, disassembly, and cleaning of the magazine is recommended.

If the magazine feeds fine or the issue is present on all magazines, check whether the feeding tube in the gun is dirty or damaged in any way. You can use a cleaning rod to clean out any debris that is stuck inside the feeding tube.

If you notice a sharp edge or burr on the bottom of the feeding tube, this may cause feeding issues as well. You can remove the burr on this edge with some sandpaper or a sharp knife – This should not be too difficult, as the feeding tube is made from aluminium.