The Test Circuit Pro is designed to simplify the process of testing partwork electronic components. However, to safely test any electrical component it is important to closely follow the instructions and, if in doubt, stop and seek advice.
The Test Circuit Pro contains sensitive electronics, it is important to ensure that you:
Test sockets
Each section of the Test Circuit Pro is fitted with 2 different sized sockets, the left socket in each section is a 1.25mm pitch JST Micro, the right socket is a 1.5mm pitch JST ZH. Both are commonly used in partwork models.
A set of adapter cables is supplied to enable you to test components using the 2.0mm pitch JST PH plugs and the JST 2.54mm pitch Dupont connector. These adaptor caables connect to the left JST Micro socket on each section.
Unusual cable?
If you come across a new cable not catered for by our standard connections or cable adaptor kit, please let us know, and we’ll try to accommodate in a future cable adaptor accessory kit.
Power source
The Test Circuit Pro can be powered from any standard USB power adapter with a rating of 1amp minimum via the USB-C connector at the top of the board.
All functions of the board require USB power to be provided.
In most cases, simply connecting an LED to a battery to test it without a current limiting resistor will damage the LED.
However, the LED Tester on the Test Circuit Pro allows you to safely test partwork LEDs without the need for a resistor. It is designed to test LEDs for partwork models that run at between 3v and 6v.
Simply connect the LED or LED circuit you wish to test to one of the sockets and press the test button to light the LED.
The LED tester will automatically detect the LED’s correct current rating and supply only enough power to light the connected LED(s).
LEDs have polarity, which means that electrical current can only flow through them in one direction. If your LED does not illuminate, use the polarity switch to change the direction of current and test again. If your LED does not illuminate for either polarity, then it is likely to be faulty.
Multiple LEDs
It is possible to test cables and circuits with multiple LEDs connected so long as the LEDs are of the same type. However, only use one socket at a time while testing LEDs.
The speaker tester is for testing small 4 or 8-ohm speakers of up to 3 watts typically found in partwork models. Do not attempt to test large speakers or those with an impedance of less than 4 ohms as this could cause permanent damage to the Test Circuit Pro.
Connect the speaker to the appropriate socket in the Speaker Test area using an adapter cable if required. Single press the button to hear a tune played out of the speaker. If you see the speaker light flashing in sequence with the tune but hear no sound, it means your speaker is faulty.
Only attempt to test one speaker via one socket at a time to avoid damaging the Test Circuit Pro
The Motor Tester is for testing of small sized motors typically found in partwork models rated between 3 and 6 volts. Do not attempt to test large motors as this could cause permanent damage to the Test Circuit Pro and may cause injury.
Connect the motor to the appropriate socket in the Motor Test area using an adapter cable if required. Single press the button to apply power to the motor from the dedicated on-board motor controller.
Motor Safety
- Only attempt to test one motor via one socket at a time to avoid damaging the Test Circuit Pro.
- Only test the motor for a short period of time.
- Ensure the motor can spin freely in either direction before testing to avoid short circuits and damage to the Test Circuit Pro.
Once you have tested any motor, temporarily disconnect the USB-C power from the Test Circuit Pro to reset the power regulator
The Switch Tester is for testing switches and buttons typically found in partwork models. Connect the switch to be tested to the appropriate socket in the Switch Test area using an adapter cable if required.
The blue LED will illuminate whenever the connected switch is in the closed position.
Only attempt to test one switch via one socket at a time to avoid inaccurate results.
The Test Circuit Pro includes facilities for testing individual batteries and battery boxes.
Batteries being tested are put under an artificial load during testing to more accurately determine their actual lifespan. Therefore, once the test is completed, you should remove the battery or battery box being tested to prevent the battery being drained.
Batteries can only be tested if the Test Circuit Pro is connected to USB-C power. This is because the testing circuitry requires power, and the USB-C power source is used as a reference voltage for more accurate measurement.
Rechargeable Batteries
Most rechargeable batteries such as NiMH and Ni-Cad operate at lower voltages than non-rechargeable ones, so the tester is not suitable for testing rechargeable batteries.
The battery box testers on the Test Circuit Pro are not suitable for testing Lithium-Ion batteries as they do not have a pronounced voltage drop as they discharge.
Battery Box Tester
The battery box tester allows you to test the power output from a partwork battery box.
Because not all battery boxes output the same voltage, you first need to select the correct size of battery box being tested using the selector switch below the sockets in the Battery Box Tester area. Failure to select the correct size battery box will result in an inaccurate result being displayed.
The battery box tester measures the voltage output of the batteries being tested. For most alkaline and non-rechargeable batteries this is an accurate indication of remaining lifespan.
The selector switch has four positions, each position corresponds to a voltage which can, in most cases, be identified by the number of batteries in the battery box.
- 3V– Typically 2 x batteries
- 4.5V – Typically 3 x batteries
- 6V – Typically 4 x batteries
- 9V – Typically 6 x batteries
Select the switch position that matches the battery box being tested and then connect it to one of the sockets in the Battery Box Tester area. The state of charge will be displayed on the battery box gauge.
The test circuit will automatically adjust the polarity of the connection as there is no standard.
Switch positions for popular models
There are a handful of models where the battery box voltage is lower than would be expected from the quantity of batteries in the box.
For example, the 1:8 Batman Tumbler uses eight batteries, but in parallel, meaning you would need to choose four batteries on the switch when testing it’s voltage. Selecting the incorrect switch position will not damage your battery box or the Test Circuit Pro, however it will give an inaccurate reading.
For accurate readings, please refer to the table below for popular models and their corresponding switch position:
Publisher | Model (A-Z) | Switch Position |
Eaglemoss | 1:8 Aston Martin DB5 | ![]() |
Hachette | 1:8 Batman Tumbler | ![]() |
Fanhome / DeAagostini / Eaglemoss | 1:8 Delorean Time Machine | ![]() |
Fanhome / Deagostini | 1:8 F&F Charger | ![]() |
Agora | 1:24 FDNY Ladder 9 | ![]() |
Panini | 1:8 Ferrari F40 | ![]() |
Fanhome / DeAgostini / Eaglemoss | 1:8 Ghostbusters Ecto-1 | ![]() |
Fanhome / DeAgostini / Altaya | 1:8 Knight Rider KITT K2000 | ![]() |
Publisher | Model (A-Z) | Switch Position |
DeAgostini | 1:8 Lamborghini Countach | ![]() |
Fanhome / DeAgostini | 1:43 Millenium Falcon | ![]() |
IXO | 1:8 Peugeot 205 Gti | ![]() |
DeAgostini / IXO | 1:8 Porsche 911 | ![]() |
Hachette / Agora | 1:12 Routemaster | ![]() |
DeAgostini | 1:8 VW Samba Camper | ![]() |
DeAgostini | Snoopy’s House | ![]() |
Hachette | 1:200 Titanic | ![]() |
Model not listed?
In most cases, selecting the number of batteries indicated on the switch to match the battery box being tested will be correct. However, feel free to let us know if you’d like a model added and we’ll endeavour to do so.
Individual Battery Tester
Individual AAA or AA batteries can be tested using the Individual Battery Tester. Insert a single battery into the appropriate battery holder and hold the button below it to test. The state of charge will be displayed on the battery gauge.
Anything lower than three LEDs on the battery gauge (when only two red LEDs shown) should be considered too low to be used.
Battery Safety
- Do not attempt to test two batteries simultaneously as this can cause damage to the Test Circuit Pro and possible damage to the batteries being tested.
- Damaged batteries are dangerous and can cause harm or injury.