The customer’s inverter had been connected up properly but had been severely overloaded and it would appear that the protection modules within the inverter had not operated correctly. Therefore a burning smell had been reported, just before final failure.
This was going to be a difficult repair as I had no schematic diagram for the main PCB and I was effectively going to be testing components in isolation using rudimentary methods.
A quick look around the inside of the unit revealed no obvious damage, but upon testing the IBGT transistors on the units’ high voltage output and several Zenner diodes in line with them, revealed serious damage to that part of the circuit.
These components are not cheap and collectively, the cost in parts alone would have been over £50, without my time factored in and without the guarantee that the unit would work again. On that basis, sadly, I had to inform the customer that the unit was beyond my help and probably beyond economical repair. It will therefore be disposed of responsibly at our local amenity tip.
I quite like the idea of this vacuum cleaner in that it’s lightweight, easy to use, highly portable and easy to maintain. All things that make a great product.
The particular vacuum cleaner came in to the workshop, just outside of its warranty period and had been looked after well. However, it had developed a nasty intermittent cutting-out problem when in use. I also noticed that the charger’s flex had also cracked near the wall plug, making it dangerous while charging.
First things first and it was off with the rollers and filters to clean any obstructions that might make a device like this overheat. Nothing obvious there, but all items cleaned and washed as a precaution to allow the roller to move freely and the vacuum to breathe easily.
Closer inspection of the handle area revealed a weakness in the design which had meant that the quick-release mechanism had caused an electrical connection to degrade, causing the cutting out.
The only remedy was to address the handle’s weak point with a mechanical fix and make good the electrical contact.
I hope Bosch take note and make an improvement in this area on an otherwise nicely engineered item.
I also did a small repair to the damaged flex on the charger.
Cost of a new vacuum cleaner, circa £250. Cost of screw… less than 50p (without my time of course!)
This Dyson presented with a pretty terminal case of ‘no go’. The owner had run this relatively new machine in to the ground with little maintenance so it was little wonder what happened next.
Whilst in use, the machine spectacularly went bang and tripped the main fuse board of the house. The noise and following smell was quite something I was told.
The owner had nearly rushed out and bought a new machine and was budgeting between £300 and £400 for a replacement.
I was glad I could help since I was fairly certain I knew what the problem was without seeing it. After giving the cable, switches and casing a visual inspection, it was time to delve deeper. The filters were in poor condition and the general smell of it indicated that overheating had been an issue, probably leading to premature wear on the motor.
With the motor out, the true extent of the damage became apparent. Both motor bushes had worn away to nothing and part of the brush holder had broken up inside the motor, probably while it was running, causing the noise.
I suspect that the owner had ignored the warning signs of burning smells and occasional cutting out (as the thermal overload circuitry performed its fail-safe role).
Being only a few years old, the owner had a couple of options; either replacing the faulty part with a genuine Dyson replacement (a very reasonable £40) or pattern motor kit with filter pack for under £25. The owner chose the latter on the basis of the machine’s age and the fact that both filters in the machine were also ruined.
The job took an hour, including testing before the machine was back performing its cleaning duties once more.
A note to all vacuum cleaner owners (that don’t take bags): Keep your filters cleaned every couple of months or so. Your machine will last much longer if you do.