The most common issue with the Probe is a cracked crystal, and you can test this by putting thumb pressure (similar to opening a can of pop) on the probe tip, which will separate most cracks and create a squelch as the crystal is pressed. If you have an additional probe that you can exchange it with, this will eliminate the Probe. At this stage, it could be one of three components causing this issue to occur, and it needs to be isolated. If the doppler turns on, the Power Source is good.

It is risky to put alkaline batties in any doppler with an open charging port as the alkaline battery has a high chance of leaking or overheating. If a battery has exploded in the battery compartment, the terminals should be cleaned with isopropyl alcohol to ensure you are getting a solid contact. Most manufacturers no longer sell PC boards, so replacing the main unit or sending it to the factory for service will be your best option. If your battery has the specified power by your doppler, it will likely be that your main unit PC board (includes power on/off switch) has been damaged or has failed. It is important to note that some rechargeable 9V batteries run at 7.2V, and this is often close to the threshold where the doppler will power off or not power on. Even if your battery is brand new, do a quick voltage and amperage test on the battery to make sure that the output is as required. Dopplers tend to be sensitive to voltage and amperage, and some models will shut down or not start up due to the voltage being below the threshold. The Cable and Probe will not affect the main unit while powering up. If there is no indication of any power or sound, you can isolate the issue to either the Power Source or the PC board of the Main Unit. Now that we have identified the main components of the doppler, we can isolate problems quickly to one of these components and begin the troubleshooting. It is infrequent to replace a probe PC board unless a non-waterproof probe has been submerged in fluids, in which case, you are likely going to be replacing the complete Probe. Like the Main Unit, the Probes are mostly sold as complete assemblies because the PC board would be exposed with a repair. Crystals are the fragile part of the doppler that will break when the doppler is dropped or struck. PROBE: A doppler probe is made up of a small PC Board, a Crystal assembly and a casing that will include the connection of the Probe to the PC board.

It is a lot easier to isolate a problem with a removable coiled cable. Batteries are a source of many problems with dopplers, and rechargeable models generally run better with OEM batteries than aftermarket ones.ĬOILED CABLE: The cable between the main unit and the Probe will usually have a connector on both ends however, some dopplers are hardwired to the main unit and/or the Probe. POWER SOURCE: Most dopplers will run off of alkaline batties and get approximately 500 assessments out of one battery however, some models use AC adaptors and/or charging stands with a NiMH battery in the main unit. Inside the main unit, there is a PC board (usually a single PC board with all components printed/soldered together), a speaker, casings and batteries. MAIN UNIT: In recent years, most manufacturers have been restricted to only supplying parts that do not involve exposing the PC board, which means that aside from the batteries, the main unit of the doppler can be considered an assembly. A doppler is made up of only a few components, many of which are replaceable as a complete assembly. The key to troubleshooting a broken doppler is to isolate the problem to the components affected, and this is more simple than you might think. Hand-held dopplers are delicate instruments in a high-paced environment, and it is a commonplace to have these devices in the repair department due to some form of damage or failure.

Doppler sound