what is this unknown component - Page 1
Forum section: electronics / repair

author: moose
author_rank: Contributor
timestamp: June 04, 2021, 02:23:09 am
content: HiThis component is off my Fisher & Paykel dishwasher controller PCB.Based on how the circuit it is in operates:when pin 1 is hi, pin 4 will connect with pin 2&3 which connect to GND. Pin 4 is the low end from a small fan.similarly with pin 8 & 5...pin 5 connects to 6&7 when 8 is hi.how would one even describe it so as to look up parts suppliers websites?thanks in advancemoshe

author: bob91343
author_rank: Super Contributor
timestamp: June 04, 2021, 03:00:05 am
content: It looks like a dual transistor. Or maybe a logic element that behaves as one.

author: moose
author_rank: Contributor
timestamp: June 04, 2021, 06:22:30 am
content: Hi Bob....yes, i've just discovered that a dual channel n-mosfet has the right pinouts...now to find a replacement!thanks for your input.

author: MathWizard
author_rank: Super Contributor
timestamp: June 05, 2021, 04:41:02 am
content: SMD codes, what can I say, I guess we're lucky if there's any labeling

author: amyk
author_rank: Super Contributor
timestamp: June 05, 2021, 09:02:56 pm
content: Could it be 8205 series dual NMOS? What voltages and currents are expected?

author: Unixon
author_rank: Frequent Contributor
timestamp: June 05, 2021, 09:24:29 pm
content: Looks like a dual MOSFET soldered upside-down, usually pins 1,8 are drains and pins 4,5 are gates.Google suggests Hitachi HAT2050T

author: moose
author_rank: Contributor
timestamp: June 05, 2021, 10:46:35 pm
content: yes..on the board it is upsidedown to the photo so the hitachi & renesas fit the profile.But can you tell me how you managed to identify it?

author: Unixon
author_rank: Frequent Contributor
timestamp: June 05, 2021, 10:58:06 pm
content: Quote from: moose on June 05, 2021, 10:46:35 pmNo, unfortunately it doesn't. Look at pin 1 mark, pinout is different, Drain<->Gate pins are swapped.

author: Unixon
author_rank: Frequent Contributor
timestamp: June 05, 2021, 11:06:42 pm
content: Can you show a larger piece of the board?Now it seems to me that the pins were misidentified, resistors next to pins 4,5 are probably pull-ups, then it fits standard pinout for this package.SOT-23 to the left is probably BAV99 and SOD-323 to the upper-left is some kind of diode or zener.

author: moose
author_rank: Contributor
timestamp: June 05, 2021, 11:19:19 pm
content: pins 4 & 5 go to MCU pins, pins 1 & 8 are the low side of attached peripherals so Hitachi & Renesas are correct.To satisfy your curiosity here's the bigger picture.I would still like to know how on earth you managed to ID it.

author: Unixon
author_rank: Frequent Contributor
timestamp: June 05, 2021, 11:59:00 pm
content: Quote from: moose on June 05, 2021, 11:19:19 pmOh, it's not for curiosity, but rather for context. Surrounding parts may show if a hypothesis is likely true or not.Here it all makes sense, polarity, protection diodes, pull-ups, 40V at rail and N-MOSFET rated for 100Vds.Quote from: moose on June 05, 2021, 11:19:19 pmSo, either 2050 or 4625 in top marking may indicate model number and the initial guess is that it is a dual MOSFET and we know the package is TSSOP8, which is not a hugely popular package for these. So we're making a 2nd guess that there's not a lot of parts where these three come together, so we're trying to check if "model+package+device type" search gets us where we want.

author: richnormand
author_rank: Unknown
timestamp: June 06, 2021, 12:09:45 am
content: @ mooseon your photo below the damaged chip is another one that looks similar. Is it the same number? If so does it measure the same? Can you remove it and compare the tw out of circuit?Again assuming it is the same number chip.

author: moose
author_rank: Contributor
timestamp: June 06, 2021, 12:18:34 am
content: yes..there are 3 chips the same...1 below the other. in the photo..in fact what i did was replace the faulty chip with (an unshorted) one from another board.The biggest problem with working on this controller is that i cannot test it when its powered up as it is in an inaccessible enclosure. And to rig up a jib to test it OFF the machine means i have to set up a skeleton machine on a worktable else the MCU simply reports errors because nothing is connected that it tests on startup.(Plus it also has 240V coming in on 2 pairs of connections)...its a very nice dishwasher until you have to start working on it!

author: amyk
author_rank: Super Contributor
timestamp: June 06, 2021, 03:47:17 am
content: Unfortunately I can't find any seller's pictures to confirm but I think Unixon got this one.