Need to know IC name - Page 1
Forum section: electronics / repair

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 09:03:17 am
content: Hello allI am new in this forum and this is my first topic.-I have damaged IC in the screen board of ete video intercom system type T-708c.please, I want know its name.See attached image.

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 12:07:39 pm
content: please help me

author: Simon
author_rank: Unknown
timestamp: November 19, 2019, 12:34:17 pm
content: The number is rubbed out, so what do you want us to do? bumping your thread hours later won't help.

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: November 19, 2019, 12:36:17 pm
content: can you read any digits from the IC?

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 07:27:24 pm
content: Quote from: EEEnthusiast on November 19, 2019, 12:36:17 pmthe short circuit caused the damage of writing of the IC

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 07:37:22 pm
content: Quote from: Brave on November 19, 2019, 07:27:24 pmthe IC is like this

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 07:50:44 pm
content: Quote from: Simon on November 19, 2019, 12:34:17 pmthe short circuit caused the damage of writing of the IC

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2019, 08:28:28 pm
content: It looks like a buck regulator, a good starting point would be buck regulators in an 8 pin SOIC package, it shouldn't be too hard to identify the pinout, the inductor and freewheel diode are easily identified.

author: Brave
author_rank: Contributor
timestamp: November 19, 2019, 09:05:20 pm
content: Quote from: james_s on November 19, 2019, 08:28:28 pmthank you sircan you give an example of this regulators.

author: fzabkar
author_rank: Super Contributor
timestamp: November 19, 2019, 11:17:25 pm
content: The "FSC" marking could point to Fairchild Semiconductor Corp, which is now a subsidiary of ON Semiconductor.I would start by identifying the other ICs, in particular U9, U6, U1 and U8. This should hopefully tell us which supply voltages are generated onboard.Can you identify the markings on the two resistors above D1? I believe these would be the feedback resistors for the buck regulator. We could then estimate the likely voltage at the feedback pin of the regulator, which would help to narrow down the candidates.Also determine which pin connects to L3 and the cathode of D1. That will be the Lx output of the regulator.The regulator's Vcc and Ground pins should be easy to determine.

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2019, 11:55:37 pm
content: I would start with the parametric search on Digikey and look for buck regulators in a SOIC-8 package, then start comparing pinouts. It's possible that it's something like the NCP3170ADR2G, it's also possible that there are multiple parts that will work.Another thing you could do is post the exact make and model of the device and maybe someone else with the same unit can look at theirs.

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 01:00:48 am
content: Quote from: fzabkar on November 19, 2019, 11:17:25 pm

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 01:07:39 am
content: Quote from: Brave on November 20, 2019, 01:00:48 am

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: November 20, 2019, 02:39:55 am
content: My best guess is the NCP3170. You can try that and see if it works.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 05:40:27 am
content: The pinout of the NCP3170 does not match the circuit:https://www.onsemi.com/pub/Collateral/NCP3170-D.PDFThe Eon EN25F10-100GIP chip is a 3.3V serial flash memory:file1.dzsc.com/product/14/07/23/128551_013504113.pdfThe BM1117-1.8 is a 1.8V LDO regulator:http://www.bookly.com/images/BM1117.pdfThe MST712CX-LF is made by Morningstar Semiconductor (Mstar). I haven't been able to find much about it, but these SoCs usually require a Vcore and a Vio voltage.I suspect these are 1.8V and 3.3V, respectively, but I haven't been able to identify the "246" regulator IC.Edit:Where does the Vcc pin of the flash IC go? Does it connect to L1 or L19? That will be the +3.3V regulator.The Vcore supply is more likely to be around 1V or so. If the two feedback resistors are 103 (10K) and 242 (2.4K), then …Vfb = (10 / (10 + 2.4)) * 1 volts = 0.806 volts0.8V is a typical feedback voltage for these buck regulators, so Vcore = 1V might be in the ballpark.Edit #2:I'm wondering if I'm wrong about the "FSC" marking. It seems that the designer of the PCB has chosen "off-brand" ICs, so ON Semiconductor would seem to be an unlikely fit.

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 08:17:51 am
content: Quote from: fzabkar on November 20, 2019, 05:40:27 amthank you sircan you put the modification in the picture?

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 09:31:39 am
content: Hello allwhat about OB3370 ?

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 09:58:19 am
content: I found that :+12 connected to pin 2.GND connected to pin4.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 12:13:33 pm
content: Does pin #8 of the EN25F10 IC connect to L1 or L19?The OB3370 is a completely different chip (LED backlight driver):https://pl-1.org/getproductfile.axd?id=3583&filename=OB3370.pdf

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 07:27:04 pm
content: I found a parts list for a SONY DA-792:https://remont-aud.net/dump/lcd_dvd_tv/sony/sony_da_792/318-1-0-7022The list includes MST712CX-LF and EN25F10.The buck regulator is a TD1410.TD1410, Techcode Semiconductor, PWM Buck DC/DC Converter, 2A, 380Khz, 20V, SOIC-8:http://dalincom.ru/datasheet/TD1410.pdfhttp://www.techcodesemi.com/datasheet/TD1410.pdfThe pinout is a match. However, the feedback voltage is 1.222V, which means that …Vout = 1.222 x 1.24 = 1.52VThe TD1410 requires an external Schottky diode, as does the video intercom PCB. If we could confirm that the Vcore requirement for the MST712CX SoC is 1.5V, then I think the TD1410 would be a suitable replacement.Edit:This IC appears to be an equivalent.BM1410A, Bookly, step-down DC-DC converter, 2.2A, 380kHz, 5V - 23Vin, SOP-8:http://www.bookly.com/images/BM1410A.pdfIt is pin compatible with ACT4060/ TD1410 / MP1410.So it would seem that there are at least 4 possible substitutes.Edit #2:MP1410, Monolithic Power, step down switch mode regulator, 2A, 4.75V - 15Vin, 380kHz, SOIC-8:file.yizimg.com/332467/2009080605462983.pdfThe ACT4060 has a slightly higher FB voltage (1.293), so Vout = 1.293 x 1.24 = 1.60VACT4060, Active Semi, step-down DC/DC converter, 2A, 420kHz, 4.5V - 20Vin, SOP-8:file.yizimg.com/332467/2009072110594237.pdfYet another substitute (FB = 1.222V):FP6182, Feeling Technology, 2A, 23V, 380KHz Step-Down Converter, SOP-8:http://www.feeling-tech.com.tw/km-master/ezcatfiles/cust/img/img/24/fp6182v061-g1.pdf

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2019, 07:30:59 pm
content: Something that has been nagging me though, when a buck regulator fails it's common for the output voltage to go all the way up to the input voltage, so usually whatever it powers will be fried.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 07:37:38 pm
content: The OP should measure the resistance between the coil and ground. That should tell us whether the SoC is shorted.FWIW, Sony's NS756 TV DVD player uses the same SoC. A service manual might be helpful, if someone could find it.The MP1410ES is available from Mouser for AU$1.59:https://au.mouser.com/ProductDetail/Monolithic-Power-Systems-MPS/MP1410ES-LF-Z?qs=sGAEpiMZZMv0keMCjoUGAeAtVwFI8TFb

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 08:45:55 pm
content: Quote from: fzabkar on November 20, 2019, 07:27:04 pmthank you very much siryou gave me good informations.so, the MP1410 is the best substitute.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 08:47:51 pm
content: Bingo!FSC = Foslink Semiconductor.FSP3170, Foslink Semiconductor, WIDE INPUT 2A STEP DOWN CONVERTER, 2A, 400kHz, 4.75V - 20Vin, SOP-8:http://www.kexin.com.cn/pdf/FSP3170.pdfThe feedback voltage is 1.222V, so I think that the MP1410 should be an appropriate substitute.

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 08:51:12 pm
content: thanks to allI'll try suggestions of fzabkar.but where can I find this IC ? I mean the unused boards.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 10:04:10 pm
content: https://www.digipart.com/part/fsp3170

author: Brave
author_rank: Contributor
timestamp: November 20, 2019, 10:17:15 pm
content: Quote from: fzabkar on November 20, 2019, 08:47:51 pma great search result .... this is the wanted IC.Thank you very much sir