Need help finding replacement part (SW4506AP, I think) - Page 1
Forum section: electronics / beginners

author: vinaduro
author_rank: Contributor
timestamp: September 11, 2017, 05:25:32 pm
content: Hi there,I'm new to the forums, but I've been a great fan of Dave's YouTube channel for a couple of years now. Although I did do some electronics back in school, and have tinkered with the odd project, I am basically a complete newbie when it comes to electronics, so please forgive me if my question is stupid.Background (you can skip this part if you like):The wife and I bought an automatic pet feeder from what Americans would call a Thrift Store. We bought it for the equivalent of ~$6. Now I knew that it likely wouldn't be working, but figured I could use the bin and motor hooked up to a raspberry pi, to control the feeder. I eventually got around to plugging it in, and the motor just turns, but the front display does not come on. So I decided to open it up, and take a quick look (yes, I know I should have taken it apart before turning it on). Inside, I found an IC that has clearly let the magic smoke escape.The Problem:I have Googled the heck out of what I think is the part number, but I can't seem to find anything useful. I have attached the best photo I could take with my phone (the best photographic device available to me). I live in South Africa, so I want to try and source the part locally, but searching the local suppliers's websites, also yielded no results. I'm hoping one of you could possibly help, by giving me an alternate part that I can search for, or ask my local suppliers for.Please let me know if you need (or want) more details or photos.Kind regards,Vin

author: SeanB
author_rank: Super Contributor
timestamp: September 11, 2017, 06:29:33 pm
content: Photos of fromt and back of the board will help, so that we can either figure out what it was and a replacement, or suggest a work around.

author: sanwal209
author_rank: Regular Contributor
timestamp: September 12, 2017, 09:57:14 am
content: Seem like optocouplerhttp://datasheet.octopart.com/HCPL-4506-Avago-datasheet-7552030.pdfFront and back side photos will be helpfull

author: vinaduro
author_rank: Contributor
timestamp: September 12, 2017, 04:24:49 pm
content: Hi,Thanks for the replies.I am unable to upload the images to the forum, as they are too large, so I have shared them from Onedrive:https://1drv.ms/f/s!Am1QqWom5z27_UUg11oF6yFmhCxuI have marked the broken chip, as well as the power input.Please let me know if you need more / better images.Kind regards,Vin

author: capt bullshot
author_rank: Super Contributor
timestamp: September 12, 2017, 04:54:33 pm
content: Looks like some kind of a voltage regulator or switch. Can't see if three of four pins are connected. SW4506AP seems to be the correct IC number, google brings up some chinese sites (one could order a 10000 pieces for a small price as far as I understood) but no datasheet.You could try to do some reverse engineering (where do the three or four connected pins go to, especially, do they go to the power input, does this IC appear to provide power for other parts, ...), then we could do some guessing.

author: vinaduro
author_rank: Contributor
timestamp: September 12, 2017, 05:21:31 pm
content: Thanks a lot Capt.I must be honest, I didn't even think of the fact that not all of the pins are connected. I will investigate further, and provide feedback.Kind regards,VinP.S. I like your signature.

author: Assafl
author_rank: Frequent Contributor
timestamp: September 13, 2017, 06:47:13 pm
content: Seems like only pins 1-4 are connected.Pin 1 seems to go to the red wire (probably +V or maybe battery?)Pin 2 is VccPin 3 goes through switch S6 to the SOIC on the top right.Pin 4 goes under blob. Maybe Gnd?What does S6 do?My guess is some sort of battery charger or a power-on chip to conserve battery. Or an actuator control. Where does the actuator (that hands out the feed) connect?The other chip (next to it) is a TDA2822 low voltage power amplifier and is connected to the speaker. I think the blobbed chip next to it is the voice recorder (probably and ISD something). My guess is you record a "Supper time rexy" message and it plays it to the pet being fed.I guess the eeprom next to it is for software and maybe storing the timetables, and the chip next to it is a microcontroller. The blob in the center is probably for the LCD. My bet is Holtek HT1628.http://www.holtek.com/productdetail/-/vg/ht1628