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

[Mark Harriss]

I have a F&P MW059 pride 5.5Kg washer with a blown motor board:
this includes both fuses on the board, a few mains tracks vapourised
and several of the power diodes short or physically disintergrated.

Can anyone familiar with F&P washers advise me about a source of
exchange motor boards to suit these: part No. 426974

Also I notice the rotor appears locked with the tub, is this normal
for a powered down machine?.

tia
Mark Harriss

 

[budgie]

I have a F&P MW059 pride 5.5Kg washer with a blown motor board:
this includes both fuses on the board, a few mains tracks vapourised
and several of the power diodes short or physically disintergrated.

Can anyone familiar with F&P washers advise me about a source of
exchange motor boards to suit these: part No. 426974

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.

http://www.dougsmithspares.com.au/AboutUs.htm

Also I notice the rotor appears locked with the tub, is this normal
for a powered down machine?.

Yes.

 

[Mark Harriss]

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.

http://www.dougsmithspares.com.au/AboutUs.htm




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.

 

[budgie]

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.

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.

 

[Mark Harriss]

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.

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.

 

[Tops]

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.

 

[Tops]

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.

http://cgi.ebay.com.au/Used-Fisher-...518899052QQcategoryZ20714QQrdZ1QQcmdZViewItem

 

[Tops]

Hi Mark,
below is a link to the F&P spare parts manual for your washer if of any use.
http://tinyurl.com/8mgz3

 

[budgie]

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

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.

I read somewhere that engaging the active braking by opening the lid in
spin cycle can kill some machines.

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.

 

[Mark Harriss]

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.

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

 

[[email protected]]

WWW.stokes-aus.com.au and seach for f&p you will find all info and
cross ref if not send email to [email protected] and i will send
it

 

[Mark Harriss]

WWW.stokes-aus.com.au and seach for f&p you will find all info and
cross ref if not send email to [email protected] and i will send
it

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

 

[budgie]

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.

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.

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.

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.

 

[Mark Harriss]

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

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.

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.

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

 

[Mark Harriss]

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