Unknown board for car need fix. - Page 1
Forum section: electronics / repair

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 08:08:12 am
content: Hi CommunityI have some few q´s about a board there inside this vintage car.My car have the digital dashhttps://drive.google.com/open?id=1ufGQuhZ-SDCN6eLmb1X6ssmDrw7pd4Z6The board have a broken componet that i can´t find out what is so i have replace it:https://drive.google.com/open?id=1p9QeC4Vs85zRiGfiLvNVN0ltkgMS2HqKHere it is? what is it? where can i buy a new one?https://drive.google.com/open?id=1KU9jeeU6tjrZ9n5kw1pyqrXPagUAVLb0Someone tells me its a National Semiconductor TO-220-5??i want to keep the electronics alive for longer and now its starts to become old so want to replace what needed to be replaced.can the community help me telling me the componets so i can buy new ones.https://drive.google.com/open?id=1buNIjWZPVoKo3OQcdKCRjq_KsJvIeQWnhttps://drive.google.com/open?id=1Mmh5z3EyWdGubFfIKVGvIjdzIOo3uDn1https://drive.google.com/open?id=1gTPWkqzelHPPYM0ZjX_MUzd25wumCV_xhttps://drive.google.com/open?id=1x16kRkMxtk6P_oDbFzIh_U9WYhrYDQDOHope you alle can help me.//Jonas Villadsen

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 19, 2019, 09:01:17 am
content: That's, very likely, a switchmode regulator, an LM2576 or something like that. Let us see a photo of the other side of the pcb.

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 10:39:49 am
content: Here you got the back sidehttps://drive.google.com/open?id=1A9wH8dg_8RasHU6sIN1Y5TFlQk7e4-mQhttps://drive.google.com/open?id=1ABoCJ7R9rfZ0p_fWbS60rgAl_CjimDW-https://drive.google.com/open?id=1AKFNMVjOqMiYrN522V0q0ddMh9wFoQMghttps://drive.google.com/open?id=1AGj5SjtKHp4j24QS0ToRNgixuwOmP9LO

author: SilverSolder
author_rank: Super Contributor
timestamp: November 19, 2019, 12:48:29 pm
content: Hi Jonas, You might get more help if you attach the images to your post, rather than linking to them.Many people will not click on unverified links (you shouldn't either!).

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 19, 2019, 01:05:39 pm
content: If that's a 2576, pin #1 (Vin) should go to BAT/+12V, pin #3 to pin #63 of the HD44790 (GND), and pin#2 (OUT) to HD44790 pin#22 (Vcc) through a coil. Follow the pcb traces with the tester, look at the datasheets, and try to guess if it makes sense. For example: looking at the diagram in page #1 of the LM2576 pdf, try to find D1, COUT and L1 in the pcb.LM2576:https://www.ti.com/lit/ds/symlink/lm2576.pdfHD44790:https://pdf1.alldatasheet.com/datasheet-pdf/view/129657/HITACHI/HD44790.htmlQuote from: SilverSolder on November 19, 2019, 12:48:29 pmWatt? Why? It's a google drive link.

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 01:16:39 pm
content: HiI tried to put in the pics but eevblog did not put them in.why i had to go with the link thing.i can try again.

author: SilverSolder
author_rank: Super Contributor
timestamp: November 19, 2019, 02:55:27 pm
content: Quote from: GeorgeOfTheJungle on November 19, 2019, 01:05:39 pmWhere I work, you would be taken out back and shot by the IT security bods for clicking on a link that leads to... what? Nobody knows what is at the end of a link that looks like someone's Google Drive. In particular, a new forum member that could be a mobster for all any of the established community knows (Jonazz, this is not directed at you personally of course!)."Think before you click"

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 03:10:10 pm
content: Why are you wasting my/our time with this?im here to get information from experts TI can not help me.i want to fix this with help from all over.if i dont have time to sit down and learn how this forum works then i have to take the fastest way likes. from my own drive.

author: Gyro
author_rank: Super Contributor
timestamp: November 19, 2019, 04:32:14 pm
content: Quote from: SilverSolder on November 19, 2019, 02:55:27 pmWhilst I agree that in-post images are, by far, preferable in all respects, the OP is far from unique in doing it. I'm not sure why you're choosing this thread to make such an issue of it. He's a newbe with straightforward question.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 19, 2019, 04:42:48 pm
content: Quote from: SilverSolder on November 19, 2019, 02:55:27 pmBollocks. You never know what's at the other end until you 1)click and 2)get the response.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 19, 2019, 06:18:09 pm
content: Quote from: Gyro on November 19, 2019, 04:32:14 pmIt's been remarked in other threads as well.

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2019, 06:47:30 pm
content: Quote from: SilverSolder on November 19, 2019, 02:55:27 pmWhere I work, Google Drive is used for hosting all of our internal documentation. It was not my choice to migrate to G-suite but whatever. I block all scripts by default so not too concerned about clicking on a link.

author: jancumps
author_rank: Unknown
timestamp: November 19, 2019, 06:55:29 pm
content: I advised the OP to post the question here, when I saw his question on another website where we didnt’t know the answer.I should have warned him that attitude towards new members is going down the drain here lately

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2019, 06:59:20 pm
content: Well there are a few people who lack tact, but hopefully that doesn't scare him off. I'm happy to help at any rate, although not familiar with that specific component. I don't see any other parts on there that I would replace unless they are determined to be bad. It should even be possible to repair the broken off part if a replacement cannot be located. You can use a file to grind down the epoxy to expose enough of the broken leads to solder new wires to.Here are the pictures for those who are paranoid about links.

author: Macbeth
author_rank: Super Contributor
timestamp: November 19, 2019, 07:41:09 pm
content: Car make: UnknownCar model: Unknown (the owner knows, but hey, it's "Vintage")Board function: UnknownRandom links: UntrustworthyNew Poster: Unknown/Untrustworthy/TrollHow somebody doesn't provide the bare minimum information without having to be co-erced when asking such a simple request is beyond me.

author: SilverSolder
author_rank: Super Contributor
timestamp: November 19, 2019, 07:43:28 pm
content: Poor design decision to have a component flapping in the breeze on an automotive board... almost bound to suffer from metal fatigue like this due to vibrations.I agree with @james_s, the easiest is to re-mount the component that fell off (and glue some supporting structure on the board to make it last...)Perhaps the whole board can be sourced from the US, where they should be common enough... (eBay?) - assuming the car is an 80's/90's Pontiac Firebird

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 07:49:29 pm
content: Pontiac firebird 88 with digital dash.

author: SilverSolder
author_rank: Super Contributor
timestamp: November 19, 2019, 07:50:53 pm
content: Quote from: Macbeth on November 19, 2019, 07:41:09 pmPeople are such utter snowflakes nowadays too, you can't point out simple facts without upsetting their delicate sensibilities. Why, the other day I pointed out to a lady at work that her bottom is a bit on the large side. As a thanks, she almost slapped me! Sheeez....

author: Jonazz
author_rank: Contributor
timestamp: November 19, 2019, 07:54:10 pm
content: The board show the miles plus can change some settings.The problem is. its the owner before me who lost the part.So i dont have it.Interresting to see how evil and down looking this community is! like to where it is embarrising.I was in my good mind asking for help here! but TI can not help. and you just kicking me and pissing on me.Hope you feel good there back behind your screen.

author: SilverSolder
author_rank: Super Contributor
timestamp: November 19, 2019, 07:55:32 pm
content: Quote from: Jonazz on November 19, 2019, 07:49:29 pmCool car! - you can probably easily source that part from the US, once the part number has been identified.

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2019, 08:02:11 pm
content: Quote from: Macbeth on November 19, 2019, 07:41:09 pmMake and model are irrelevant, unless one of us is familiar with that specific car in which case we would recognize it anyway. The board function is not unknown, he said it's part of a digital dashboard and it has a clearly visible HD44790 LCD controller on it, I think that's obvious. Would it matter anyway though? I've reverse engineered plenty of unknown boards, it's not that difficult to figure out what the unknown part is. They're not random links, they're Google drive links, the danger is relatively low. New poster, so what? We all start out as a new poster, how do you expect someone to know all the etiquette right off the bat? Cut him some slack for being new.How somebody can feel it necessary to throw such a fit over something so minor is beyond me.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 20, 2019, 01:58:53 am
content: Quote from: Jonazz on November 19, 2019, 03:10:10 pm Interresting to see how evil and down looking this community is! like to where it is embarrising.I was in my good mind asking for help here! but TI can not help. and you just kicking me and pissing on me.Hope you feel good there back behind your screen.Quote

author: Jonazz
author_rank: Contributor
timestamp: November 20, 2019, 08:49:26 am
content: I do think it is impossible to find a skrapped board to install it into my car..Not many cars had these digital dashes...Also for the time they.. where unstable but cool looking!And this is only the first board the preowers all ready took it out... after this board i have to go into all the other boards.Did not know that only that small part was that rare.. :/

author: Haenk
author_rank: Super Contributor
timestamp: November 20, 2019, 09:11:01 am
content: Zooming in reveals the part missing.(Yes I know, first time poster, blah blah, dubious picture on the Interwebs thingie 'n stuff...)

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 20, 2019, 09:16:25 am
content: Maybe 1573 is GMs code for the LM1575-33 ?https://pdf1.alldatasheet.com/datasheet-pdf/view/203233/NSC/LM1575_07.html

author: sean0118
author_rank: Frequent Contributor
timestamp: November 20, 2019, 09:29:35 am
content: Quote from: Haenk on November 20, 2019, 09:11:01 amWhere did you even find that pic? Or do you have the board in your possession?It's good to have another image of the board but Jonazz did post an image of the missing part earlier, it's a National Semiconductor "8432 1573 REL".I'm guessing 8432 will be the datecode and REL might mean high reliability? But 1573 doesn't seem to exist online. We need someone with some old National Semi databooks...I read on one of thecar forumsthat the board is supplied with 12V. Both the HD44790 (which apparently drives the odometer display and records miles) and the 52801 EEPROM require 5V. So it seems this may be a 5V regulator? Unless 5V comes from off board as well?

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 20, 2019, 09:34:41 am
content: Quote from: sean0118 on November 20, 2019, 09:29:35 amWhere's that?

author: sean0118
author_rank: Frequent Contributor
timestamp: November 20, 2019, 09:42:07 am
content: Quote from: GeorgeOfTheJungle on November 20, 2019, 09:34:41 amIt's the DIP package, you canjustmake it out with the photo Haenk posted. It's mentioned on the car forum i linked too. Maybe Jonazz could confirm it does say "52801"?

author: SilverSolder
author_rank: Super Contributor
timestamp: November 20, 2019, 11:23:08 am
content: Quote from: Jonazz on November 20, 2019, 08:49:26 amIf you are a big manufacturer (like AC Delco, who probably made this board), it is common to buy "special versions" of electronic components. These specials will get unique part numbers for that particular manufacturer. There may be no difference at all between the standard part that it is based on, other than giving AC/Delco a special quantity discount without depressing the pricing for the standard part!So the trick here is to identify which standard part that AC Delco's "saturday night special" actually is under the hood.Most of the "unstable" problems are likely to be the connectors, rather than the electronics themselves! - perhaps time to get acquainted with products like DeOxit and VW's "Stabilant 22" to keep this 'bird flying...

author: Jonazz
author_rank: Contributor
timestamp: November 20, 2019, 03:57:34 pm
content: Eprom does say 52801 yes.

author: YetAnotherTechie
author_rank: Regular Contributor
timestamp: November 20, 2019, 08:13:11 pm
content: What is the part number for the little transistor next to the eeprom?

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 20, 2019, 08:15:26 pm
content: Should be pretty straightforward to follow the traces and confirm that it's a 3 terminal regulator (look up the data sheets on the other chips and see if the Vcc lines go to the chip. That will also give you the voltage). Back in 88 they're not going to be doing anything particularly tricky in a 3 terminal device. Hopefully they used the standard pinout.

author: jancumps
author_rank: Unknown
timestamp: November 20, 2019, 08:24:42 pm
content: Quote from: PaulAm on November 20, 2019, 08:15:26 pmI first thought it was a 3-terminal device too, but it's a TO-220-5. 5 pins.

author: PaulAm
author_rank: Frequent Contributor
timestamp: November 20, 2019, 09:06:48 pm
content: Maybe something like an LT1529, but what was contemporaneous in 1988?Same deal though, trace the connections and see if it looks like it should be a 5 terminal regulator. Seems like the most likely thing, that package is for handling significant power.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2019, 10:06:36 pm
content: I have seen linear regulators that have an enable pin in a 5 pin package like that. Either way tracing out that part of the circuit and drawing a schematic ought to make it obvious.

author: fzabkar
author_rank: Super Contributor
timestamp: November 20, 2019, 10:37:25 pm
content: If it's a switcher, then where is the inductor?Here is the EEPROM datasheet (5V only):https://www.thirdgen.org/forums/attachments/electronics/302778d1463432237-hacking-into-86-88-ncr52801-datasheet.pdfI have checked my 1982 NS Linear Data Book, but there are no "1573" parts.Maybe it's worth trying here:www.bitsavers.org/components/national/_dataBooks/Nothing here either:http://www.bitsavers.org/components/national/_dataBooks/1984_National_Linear_Supplement.pdfIt seems odd that the designer used vibration resistant capacitors (as per MIL spec), but did not anchor the regulator in a similar fashion.Some alternative pinouts:https://www.ti.com/lit/ds/symlink/lm2931-n.pdfwww.ti.com/lit/ds/snvs770i/snvs770i.pdf

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2019, 11:50:02 pm
content: I thought perhaps those cylindrical black components could be inductors but I'm not sure, if I had the board in front of me I could figure all this out in about 5 minutes but I don't so I have to rely on the pictures. If I can find the time I'll print out the pictures of both sides and reverse engineer the regulator section but I'm fairly busy with my day job and other chores so I can't make promises.The part is almost certainly house marked, this is or at least was a very common practice. The numbers printed on it will have significance only to the manufacture, it is their own part number printed on what is almost certainly a standard part.

author: fzabkar
author_rank: Super Contributor
timestamp: November 21, 2019, 01:06:07 am
content: Here is a fixed, dual output, 5V + 5V, linear regulator that was available in 1984 (LM2935TV):https://www.onsemi.com/pub/Collateral/LM2935-D.PDFIt was designed for automotive applications.

author: Haenk
author_rank: Super Contributor
timestamp: November 21, 2019, 07:58:29 am
content: (nonsense deleted)

author: fzabkar
author_rank: Super Contributor
timestamp: November 21, 2019, 10:02:48 pm
content: @Jonazz, you have been asked twice to trace the Vout and ground pins of your mystery part. Please help us to help you.You have the datasheets for the MCU and EEPROM, so you know their Vcc and ground pins. Now use the continuity mode of your multimeter to locate the corresponding regulator pins.Also measure the voltages coming into the PCB. One of them will be the +12V battery supply.

author: fzabkar
author_rank: Super Contributor
timestamp: November 22, 2019, 04:11:53 am
content: From that other forum …https://www.thirdgen.org/forums/electronics/732858-hacking-into-86-88-a.htmlH: to F from speedometer, +12 V, hot in runG: pin 15 (from big digidash conn), to H from speedometer, VSS input LT GRN/BLK wireF: pin 16, +12 V, hot in runE: pin 19, display dim input, did not use this oneD: not usedC: pin 21, +12 V, hot at all timesB: not usedA: pin 24, GND, to fuse G118

author: stevelup
author_rank: Regular Contributor
timestamp: November 22, 2019, 09:07:22 pm
content: Quote from: Jonazz on November 19, 2019, 07:54:10 pmI think you are -massively- overreacting. No one has been that rude really. The point about links -vs- embedded images was a fair one, as was the fact that you gave no information about the vehicle.If anyone has been rude, I’m afraid it was you.

author: fzabkar
author_rank: Super Contributor
timestamp: November 22, 2019, 09:26:19 pm
content: After reading the detailed explanation at thirdgen.org, it appears that the EEPROM stores the odometer reading in 10 mile increments. This is because it has a finite number of write cycles, namely 10,000. Its capacity allows for 8 odometer readings consisting of 32-bit words (including ECC bits). So 10,000 x 8 x 10 miles = 800,000 miles.The in-between odometer readings are preserved in the MCU when the ignition is switched off. This would support the idea of separate 5V standby and 5V run supplies.Edit:Here is the OP's original thread:https://www.element14.com/community/thread/74328/l/pontiac-firebird-88-boardPontiac 1988 Firebird Service Manualhttps://depositfiles.com/files/ty1vrpu5x(102MB)Page 1425 shows connector C2.pin 21 = battery voltage = memory input - hot at all timespin 16 = ignition

author: Jonazz
author_rank: Contributor
timestamp: November 29, 2019, 09:35:56 am
content: Quote from: fzabkar on November 21, 2019, 10:02:48 pmSorry i know. i been out town for work. now i have a little time again in this weekend. so im on it.

author: Jonazz
author_rank: Contributor
timestamp: December 18, 2019, 09:50:03 am
content: Hi all!Im super happy for everyone trying to help me!Im sorry that im so slow. but i been working last six weeks plus weekends.Im 100% open to send it out in the world for who that want to play with it and analyse it. im paying for the shipping each way plus spare parts!Who is up for the challenge?//Jonas

author: fzabkar
author_rank: Super Contributor
timestamp: December 19, 2019, 03:17:55 am
content: Maybe Per Hansson (https://www.eevblog.com/forum/profile/?u=121676) could help you