Help identify SMD component on MIELE Washing machine - Page 1
Forum section: electronics / repair

author: xoom
author_rank: Regular Contributor
timestamp: September 14, 2017, 01:04:04 pm
content: This is fromMiele WKB130 WCSwashing machine. Machine doesn't turn on at all.. only have red led on board that's illuminated. And 15V is coming out of primary DC-DC converter.. then there is other (i guess) which gets 15V but nothing going out (maybe enable pin is on it) after that it has 1117 regulator to 3.3v (nothing on in/out)photo is attached if someone can identify that chip (it's sot23-6)IL3FM

author: tszaboo
author_rank: Super Contributor
timestamp: September 14, 2017, 01:26:37 pm
content: I think it is L3FN with the "I" being the pin 1 marker.

author: xoom
author_rank: Regular Contributor
timestamp: September 15, 2017, 08:36:59 am
content: even with this code cant find anything.. :/

author: Zucca
author_rank: Unknown
timestamp: September 15, 2017, 09:10:22 am
content: Desolder it and look on the bottom mark, maybe there is something there: i.e.https://www.infineon.com/dgdl/Infineon-IRS10752L-DS-v01_02-EN.pdf?fileId=5546d462533600a40153567308ca276dMan I hate when they do that...

author: xoom
author_rank: Regular Contributor
timestamp: September 15, 2017, 09:25:02 am
content: on bottom isM395and attached pcb with some annotations..

author: xoom
author_rank: Regular Contributor
timestamp: September 15, 2017, 09:36:33 am
content: im thinking maybe there are some enable pin or something.. or its just problem by it self.. they made those washing machines like top secret projectsno info at all.. + custom chip names.. that machine have 2 board.. bottom (Power board with VFD driver) and upper human interface.. upper board also gets +15V but no reaction.. visualy machines bottom had water leak.. but on board no burning / corroding signs.. and this 1117 3.3 LDO have to supply 3.3v for all controllers on power board.. which is missing..

author: Armadillo
author_rank: Super Contributor
timestamp: September 15, 2017, 10:29:23 am
content: I think its a DC to DC converter, try LT1934

author: xoom
author_rank: Regular Contributor
timestamp: September 15, 2017, 11:15:37 am
content: i also think that its DC-DC converter but by your suggested part its bit different.. PIN 1 is only connected to capacitor ant capacitor goes to inductor.. other pins somehow looks okmaybe need to try short SHDN pin to VIN..

author: Armadillo
author_rank: Super Contributor
timestamp: September 15, 2017, 11:22:39 am
content: Quote from: xoom on September 15, 2017, 11:15:37 amTry trace the circuit as per attached. What's the difference?

author: xoom
author_rank: Regular Contributor
timestamp: September 15, 2017, 11:36:52 am
content: i tryed to force SHDN pin high.. but its no like thatpower supply goes to CC .. im set it to 100mA and was hoping to see anything on output.. but nothing comes out..

author: MichR
author_rank: Contributor
timestamp: September 15, 2017, 07:25:08 pm
content: I don't know I will be of much help here, but I'm quite sure it's a step-down converter. Schematics and pinout of most of these converters are consistent with the circuit on your board.For example, check Richtek's converters, likethis one.

author: floobydust
author_rank: Super Contributor
timestamp: September 15, 2017, 08:00:21 pm
content: ConsiderMPS2357 buck converter. SMD marking code is IL3xx; last letters are case code.