Simpson Washing Machine SMPS Repair & Failure Analysis

[@bertbrecht7540]

I fixed my washing machine that was out of warranty by about 6 months by replacing the power supply board that was 'only' a third the cost of the machine. I wish I had seen this video then and been a bit more of a detective. The satisfaction of a $5 repair over a $200 replacement would have been immense. Thank you!

[@landcruiser1868]

Thanks for putting this video up . I have next model on , board slightly different , replaced that component along with the capacitor beside it as top looked swollen , were back in action . ✅

[@danatmonst3594]

Thank you for showing the site you bought from. Element 14 also has the chip I need, for $1.34 and the cap next to it for 34c. Its shocking that these boards sell for almost 200 aud when only a part or two has failed. In my searching for this board today I saw that simpson issued a recall on these boards!! Guessing the same part is failing for all of us tho my part has a different number but its the one with the burn marks in the gel around it. I got many years use out of my washer.. and hope to have many more. Thank you for your video!

[@landcruiser1868]

Excellent video , mine is playing up same symptoms.

[@user-gn1df7km8l]

Tim thanks for taking the time to put up the video , i have next model onwards , the same component on my board was defective and the capacitor near it , top looked to be swollen , i changed them both out and we are back in action , machine working again . cheers

[@misterbeetz]

I just stumbled upon your videos. Well done! Keep up the great work!

[@h7qvi]

Diagnosed a dead fisher & paykel washing machine where the water cooled aluminium heatsink sprung a leak from corrosion and wet the pcb. Ingenious design for guaranteed failure !

[@WizardTim]

Geez that must be some high performance racing washing machine to need a water cooled heatsink, this one I think had a 350 W motor yet the VFD heatsink never got very hot despite the confined space it's in.

[@h7qvi]

@@WizardTim it was a pancake stepper motor looking thing with a ring of magnets fastened to the tub, direct drive and vfd

[@airmann90]

Had that exact chip fail on a cheap 300w lab psu about a month ago. Took some figuring out though as it would work for quite a while before crapping out.

[@jaro6985]

Good analysis. I see a few mentions of TNY278 failing online, speculating either input voltage spike or over current. But not that many posts, and this seems to be running nowhere near its max power limit, also has MOV on the input it looks like. Although, even with the washing machine "off" this thing is always running right? So it has been going quite a few hours.

[@WizardTim]

Thanks! Yes it has both a MOV and NTC along with the appropriate X and Y class capacitors on the PCB input along with the separate line filter module, however it's worth noting the VFD and off-line switcher share the same input protection so it wouldn't surprise me if the VFD was the source of the line transients if that's what killed it. However I am leaning towards the speculation that it's a failed bond wire as the chip still worked and regulated the output voltage just fine, it's just that it overheated which would make sense if one of those three transistor sections was disconnected resulting in poor Rds(on) or bad rise/fall times. Normally I see stuff just completely die when it's killed by transients. Really wishing I cut open the new chip first and the bad chip second as I had a few new spares if I was unsuccessful. :/ When the rotary knob is in the "off" position it's in soft standby, that off-line switcher is still running and it consumes about 10 VA, however the physical power switch is very accessible on the back so it's always been turned off there, the machine likely only has 1,000 to 2,000 hours on it despite being 10+ years old.

[@lpaul2438]

Could you tear down the IC that you suspect failed from your ATX power supply for failure analysis?

[@WizardTim]

At the time I was considering doing that but I thought maybe I should wait and do that in another video about the PSU and buy some nitric acid to get a very clean die. But that will be awhile away, I have a lot of other videos I need to finish before starting another.

[@karenpayne8987]

My machine when power is turned on has a constant buzzing sound and won't start any cycle have tried to do this but nothing happens lights still work

[@WizardTim]

If it sounds like the buzzer at the end of a cycle or when the lid is open it may be that one of the many sensors is bad, eg. lid position sensor, out of balance sensor, water inlet sensor etc. However it should display an error code on the 7 segment display or beep in a pattern after a couple minutes if this is the problem. If it's not the buzzer beeping and it's something mechanically buzzing it could be the drain pump or hose is blocked by something like a sock, or the motor or motor VFD is bad.

[@tubuna730]

good job

[@h7qvi]

Far easier to clip the leads from the dip package from above, then you can remove the leads individually

[@h7qvi]

You near Melbourne ? I've got surplus stuff for decapping chips

[@WizardTim]

I'm up near Brisbane, but I'm staying away from acids until I absolutely have to use them, although I have found a place that will sell me nitric and HF.

[@h7qvi]

@@WizardTim ok. I wouldn't be able to post it easily

[@h7qvi]

The right acid and heat will disolve the package