Help Required please help me identify some components - Page 1
Forum section: electronics / repair

author: HARBINGERofDOOM
author_rank: Newbie
timestamp: June 16, 2022, 02:20:17 pm
content: Hey guys,I'm in desperate need of help figuring out what some components are on a Hornby TTS DCC decoderA bit of background, I've been handed a butt load of these decoders to fix by a friend whos part of a model railway club apparently he's been collecting them for quite some time:palm:he handed them to me to see if I could do anything with them and I've fixed a few but I still have a ton of them I can'tto be totally honest I don't have much knowledge of electronics I've dabbled with this and that and I can solder and desolder etc but knowing what each part does isn't something I'm confident with I'm learning but my old brain is slowing me down lolthere are 4 components I can't find any info on I've gone as far as completely stripping off the components to see if that helped but it didn't well not much at least the 1st is something to do with driving the motor q8+9 on the board, the 2nd marked u2 I think is some sort of voltage detection or something like that, then next is u5..... now I have no idea what this is apart from its a 9 pin BGA and on the decoders that have this ic blown or damaged the sound doesn't work it is on the other side from the sound chip and the non-sound decoders don't have this component that's as much as I've been able to figure outanyway, enough waffle here's some pic's of what I'm working with

author: fzabkar
author_rank: Super Contributor
timestamp: June 17, 2022, 04:32:37 am
content: ZXMC3AM832, Zetex, COMPLEMENTARY 30V ENHANCEMENT MODE MOSFET, N-ch + P-ch, 30V/3.7A & -30V/-2.7A, marking C01, MLP832 PACKAGE:https://datasheet.octopart.com/ZXMC3AM832TA-Zetex-datasheet-124599.pdfThis part has the correct marking, but its pinout looks wrong (mirror image):https://www.semiee.com/file/backup2/SILIKRON-SSF3056C.pdf(marking 3056C)http://silikron.com/upload01//SSF3056C%20v1.0(preliminary).pdfI expect that the pinout of the 3056C part would be the same as the C01 part. It looks like they may be wired as half bridges, in which case two of them would constitute a H-bridge.The horizontal line on the 5FHC part identifies its manufacturer as probably Monolithic Power. It looks like it might be a stepdown DC-DC converter.U4 looks like a linear LDO regulator.I think this could be the pinout of U2 ("5FHC"):Code:__NC -o| |o- NCBoost -o| |o- FeedbackLx -o| |o- GndVCC -o|__|o- Enable / Power Good ?U2I would examine the other PCBs to see whether the manufacturer has substituted equivalent parts from other IC makers.I would also compare the part markings on all the PCBs to enable us to determine which markings are date codes or batch codes.Can you tell us what the markings are on the BGA-9 IC? I suspect it is an audio amp made by Texas Instruments.Here is a TPA2028D1YZFR BGA 9 Ball 3.0 W Mono Class-D Audio Amplifier with a similar marking style:Edit:This looks like it:TPA2034D1, Texas Instruments, 2.75-W FIXED GAIN MONO FILTER-FREE CLASS-D AUDIO POWER AMPLIFIER, 2.5V - 5.5V, marking BPZ, DSBGA:https://www.ti.com/lit/gpn/tpa2034d1Edit #2:Monolithic Power's web site identifies the package style as "QFN-8 (2mmX3mm)". The part number has a "D" suffix. Also, the marking info identifies "5F" as the part code and "HC" as a Year/Week date code.https://www.monolithicpower.com/en/support/package-information.htmlhttps://media.monolithicpower.com/cms_document/Package%20Information/QFN-8%20(2mmX3mm)%20TOP%20MARKING.pdfhttps://media.monolithicpower.com/cms_document/Package%20Information/QFN-8%20(2mmX3mm)%20POD.pdfHere it is:MP2452DD, Monolithic Power, 1A, 3.3V - 36Vin, 1MHz, STEP-DOWN CONVERTER, marking 5F, QFN-8:https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP2452/document_id/255/

author: HARBINGERofDOOM
author_rank: Newbie
timestamp: June 18, 2022, 01:45:38 pm
content: thank you so much, I can't tell you how long I've been trying to identify these parts, and from the looks of things you have figured it out.Unfortunately, I will have to double-check things on Monday as I'm away this weekend visiting the inlawsAnyway just wanted to say a quick thank you, you've managed to get further than I have in the weeks ive been trying lol

author: HARBINGERofDOOM
author_rank: Newbie
timestamp: June 20, 2022, 08:06:12 pm
content: Unfortunately, I haven't had as much time free today as I planned, I did check up on the BGA chip, I think your bang on with that one the datasheet mentions BPZ as a marking code and that's exactly what I found...... once I rigged up a magnifying glass along with my eBay special microscope as these things a tinylike I said before I'm not very experienced with this level of PCB work but I'm enjoying the learning experience and quite chuffed I was on the right track (pun intended lol) with the BGA relating to the sound but without your help, I would have no idea exactly what I was looking for.tomorrow I will have a look at the other parts and then the fun part locating replacements, I had a look on Digikey for the BGA and no joy it was a quick look due to limited time any recommendations would be very much appreciated

author: fzabkar
author_rank: Super Contributor
timestamp: June 21, 2022, 05:56:28 pm
content: Mouser has the audio amp in stock in single quantities.

author: HARBINGERofDOOM
author_rank: Newbie
timestamp: June 21, 2022, 10:02:26 pm
content: Hi thanks for getting back to me, it's been another very busy day but i have made some progress and after looking on Digikey and not finding anything then looking at all sorts of random sites I had a poke around the texas instruments page and found a link too would you believe it DigikeyI did look on mouser but I was looking for one of the other components at the time along with about 100 other pages my poor laptop hasn't worked so hard everthe other part was the one marked U2 it was only a quick look as I spent most of my time trying unsuccessfully to find the part marked Q8 + 9 as I have more decoders with one of them blown than any other part, anyway the Step-Down Converter is sort of available from monolithic power but I'm guessing only in whole reel's of 3000 a few more than I actually need if I even need any at all I have no decoders with physical damage or blowouts but being as its to do with the power part of the circuit I thought it would be handy to at least know what it is and line up somewhere to buy if neededanyway many thanks again for your help, and if you or anyone else can help me find the q8+9 MOSFETs i would be eternally grateful