advice on a F&P washer with a blown motor board

Hi Mark

Our F & P failed a while ago. The Service Person stuffed it up completely. Parts kept blowing up on him. We ended up buying a different brand of washing machine all together. Much better. Thats my comment, although probably not much help to you if you really want to fix your F & P.

Regards

Not that it's much help to you in ?Qld, but there's certainly one place here in WestOz. Had to buy a new controller board for our machine a couple of years back. Was ~$160 exchange but they didn't ask for the old one.

There was a place (Doug Smith Spares) that had the diagnostics and other good info on their website a few years back, but they removed it because service organisations bitched that you and I were fixing our own machines. They certainly sell the spares.

Yes.

Thanks for the help Budgie. One final question: do these boards just blow from surges etc., or does the motor or something else take the board out of action. My board had every diode in the bridge blown and two diodes (BYW95C's) across two blown IGBT's.

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I have no clue as to why they expire. In mine there were two FETs in the "three-phase H-bridge" that went. Obviously if one breaks down conducting its opposite number is gone in a flash. I replaced the pair only to have an instant replay, so I followed the circuit back up the drive chain to the micro, which was driving one FET continuously. Obviously the fuses failed to protect much, blowing after the FETs.

A mate and I have had identical F&P 603's since 1996, and have each replaced one board. They seem to "just go".

There are some clever things about these boards - like the water-cooling for the semis. If the temp on the heatsink rises the micro just admits some more cold water, pumping some out if necessary to control the level in the bowl. Quite sneaky. But whether the electronics are truly real-world-proof is another question entirely.

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I see... this machine was given to me for free and is a week out of warranty. I can see extra damage to at least one other semi, but the fault appears identical to your own experience. Depending on the part price it should be worth a try. This machine has smartdrive V9: I wonder how the reliability compares.

FWIW this board uses 38W IGBT's throughout the design, Possibly increasing the heatsinking will help things survive, although I read somewhere that engaging the active braking by opening the lid in spin cycle can kill some machines.

Below is a link to an item on eBay that is described as a blue motor board, it is a different part number, but worth investigating. $167 delivered but a $50 rebate if you return your old unit.

Hi Mark, below is a link to the F&P spare parts manual for your washer if of any use.

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Does it have the water-cooled heatsink assembly? If so, i doubt you will get any benefit from trying to improve on this in the space available.

That's what I meant by not real-world-proof. That's what did it to mine :-((

Be aware (when servicing/repairing these at the component level) that the DC rails on the board are directly derived from the AC supply, so there is no such thing as a "cold side", and connecting a CRO (which I found necessary to trace the faulty FET drive) requires appropriate precautions.

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Very good advice, my old BWD has a removable earth link on the front panel...hang on I have an isolation tranny, I'll use it as well.

Definitely haven't found any water cooled heatsinks, I've only looked inside the console area, hmm looks like time to pull of the back covers and check out the motor assembly.

My model can take two versions of motor board I'll try and do a straight swap using one of them.

Thanks Mark

and seach for f&p you will find all info and cross ref if not send email to snipped-for-privacy@bigpond.com.au and i will send it

Thanks, i've narrowed it down to two part numbers and have sent Stokes a query.

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Ideally you need a 1kW isolation transformer - on the WASHING MACHINE. Floating the BWD could be lethal.

To look at logic level signals on the pcb you need to use two channels in differential mode, unless you want to work with a live CRO chassis. Whichever way you approach this, BE EFFING CAREFUL.

In my machine, behind the display/control panel there is a plastic snap-together box housing the pcb. Atop the pcb is a long hollow heatsink with the FETs etc fixed along each side. The inlet cold water from the solenoid passes through that heatsink en route to the bowl. The scheme in yours may well be different, being a much later model.

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Can do: I have a 2KVA safety pack tranny and a smaller 1KVA unit, I could do both the CRO and washer. If these boards are not too exxy I'll just buy one and sling it in rather than muck around fault finding the original board.

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Ahh not on this one, it has about 12 IGBT's , six of which have postage stamp sized bits of copper track for heatsinking, but no watercooling. Figures after a few generations corners would start to be cut cost-wise.

I think at this stage I'll try a replacement board rahter than fix this one: i have a few exploded devices I can't read numbers for.

Thanks Mark

My motor board has a blown transistor like device mounted below a surface mount LM393 and a surface mount 7805. It appears to be labelled "75" but the rest is obscured by the crater, does anyone have a board they could take a look at to identify the part in question?. These parts are roughly located on the opposite side to one of the mains filter electros.

tia Mark Harriss