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Repair of Hoover UNP324RM Cordless Vacuum Cleaner

paradigm

New Member
Hello everyone,
This post relates to 'an appliance' but there appears to be a lot of control 'electronics' within it.
Can anyone direct me to service information, schematic diagram, etc. for a Hoover Unplugged 32.4V Lithium UNP324RM Cordless Vacuum Cleaner? An image is attached. One of these, just out of guarantee, has stopped working - no response at all, except the lithium battery still seems to charge via the wall charger. On inspection, the 32.4V battery, the motor and switches all appear to be operational and all wiring and connectors seem to be fine. This leaves the control electronics - the main PCB of SMT components looks surprisingly complex and there is also a PCB within the 9-cell lithium battery case. The circuit boards are being powered and it is not obvious which are the output devices driving the motor.

Although I am skilled in electronics, the lack of information makes it rather difficult to know what is going on in the electronics. Looking round the Internet, no information could be found, which suggests that the problem may not be a common one. I would be grateful for any suggestions.

hoover_unp324rm_rd_01_l.jpg
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
The typical mentality of the Hoover corporation now. A vacuum a month club and no support. Congratulations, their product is subscription based. You just bought one warranty's time of cleaning.

The PCB in the battery pack prevents overcharging, short circuits and likely cell balancing. they are better known as protection boards.

Your first step, should be seeing if the battery pack is good.

The data: https://service.hoover.co.uk/advice-centre/vacuum-cleaners/unp324rm/ You have a belt and roller as a spare part, but for how long?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Can anyone direct me to service information, schematic diagram, etc. for a Hoover Unplugged 32.4V Lithium UNP324RM Cordless Vacuum Cleaner?
White goods manufacturers have never supplied schematic diagrams, the electronics boards are designed to be changed as a complete assembly - if you want to try and repair them, or even fault find, you probably need to reverse-engineer the design. Bear in mind though, it's VERY likely that a micro-controller of some kind is used, this is essentially a 'black box' that you have no way of knowing what it does.
 

paradigm

New Member
Thanks for your replies - I am in complete agreement with the comments made! Needless to say, I did not choose the item in question but it has landed with me for repair!

However, a couple of thoughts are as follows:
(1) In the UK, goods are required to be 'fit for purpose' in relation to a reasonable expected working lifespan. In spite of the statutory 12 months guarantee period there can be a period of up to 6 years when a claim can be made for a faulty item. Has anyone any experience in making such a claim?
(2) The battery seems fine (and is charging) - the motor and switch are also working. It would then seem possible to simply bypass the controller board and run the unit at a fixed single speed. There is nothing on the controller board which looks damaged or over-heated - I still think the board looks way over complicated to simply run a motor!

Thanks to all.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
(1) In the UK, goods are required to be 'fit for purpose' in relation to a reasonable expected working lifespan. In spite of the statutory 12 months guarantee period there can be a period of up to 6 years when a claim can be made for a faulty item. Has anyone any experience in making such a claim?
You're mis-reading what the legislation says (as most people do) - after the initial 12 months warranty it gives you the right to take the RETAILER to court (NOT the manufacturer) where YOU have to then prove the fault was caused by a 'manufacturing defect' - as you can imagine, this is pretty well impossible to do (particularly as it's quite probably NOT a manufacturing defect).

There's also the further problem that it's been 'tampered with' (by you), this effectively means the purchaser has now lost even those rights.
 

Musicmanager

Active Member
Hi Paradigm

A thought to share;
In the past 12 months or so I've looked at repairing two cordless cleaners, one a Dyson, the other I think was a Vax .. ..

I discovered the same fault in both.
Between the motor housing and the dust collector there is a filter surrounded by a silicon seal and within that seal there is a small magnet positioned to coincide with a Hall Sensor on the main circuit board which is the other side of a thin plastic case.

The Dyson would work when the trigger was pulled but only for a few seconds, then stop because the suction the motor created moved the filter and the magnet far enough away from the sensor to break the circuit.

The Vax would not even trigger because the magnet was somewhat ill fitting.

I got over both problems by adding a small piece of rubber behind the magnet to close the gap between magnet and sensor.

Maybe worth a try .. .. .. .

S
 

chris lyons

New Member
hello i got two same make with same problem did any one manage to sort it, it might boil to down to micro-controller i not 100% on that
 

chris lyons

New Member
ok i getting somwhere with mine i have taken the battery out and charged it up with power supply it come with it by using two wires on to tip, it now works as it should so my guess its the charging ic that has 6 legs may this is at fault
 

hyedenny

Member
Most of the circuit board is probably for charging. Since the OP says that it's charging fine, I'd say to look for the problem elsewhere. Start from the motor and work backwards.
 

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