Help needed to repair vehicle diagnostics tool - Page 1
Forum section: electronics / repair

author: Liteace
author_rank: Regular Contributor
timestamp: April 14, 2019, 06:56:37 am
content: Hi all, I know I dont post a lot on here, I think 1 post per year, so I understand if help is lacking due to me not being a regular, would someone have time and patience to help me repair my old diagnostic tool, the tool is the same as this:https://archiwum.allegro.pl/oferta/carman-scan-ii-od-1zl-bcm-i7064185090.htmlit has / had a internal ni -mh battery that leaked and rotted part of the board pcb, Ill see if I can upload some pic later.The 1st thing I have done is removed a flash chip (56-lead tsop) cleaned up the PCB, a couple of pads have come off but I think I can put some link wires on to sort that problem out, I dont think the chip is going to survive being refitted as the corner legs are weak due to corrosion.The chip is a Micron Technology 28F128J3, would this be loaded with data for the machine to work or is that just a read / write while the machine is doing it thing, if the chip is blank whats it commonly used in as I can not get one locally but maybe could salvage one from something elseThanks

author: Chriss
author_rank: Frequent Contributor
timestamp: April 14, 2019, 08:03:13 am
content: Hi!I'm glad to help you. Please contact me by pm so we can stay in touch.Later I will check the link about your diag tool when in front of my pc.I don't know why I can't open the page on my phone.Sent from my GT-I8260 using Tapatalk

author: magic
author_rank: Super Contributor
timestamp: April 14, 2019, 09:59:49 am
content: I have no familiarity with car diagnostic devices, but in general, if it's flash it probably contains firmware so the unit won't work with a blank chip.Broken pins can be repaired, though.https://youtu.be/xqkXvmvusws?t=1615And this was actually unnecessarily difficult. Below you will find some pictures of what those things look like inside. It should be safe to grind-off 1mm of plastic from the edge to gain better access to uncorroded metal.http://members.iinet.net.au/~lantra9jp1_nbn/gurudumps/decap/index.htmlhttps://arstechnica.com/gaming/2017/07/mame-devs-are-cracking-open-arcade-chips-to-get-around-drm/editMaybe less than 1mm, but that would still be sufficient even if everything outside the package is 100% corroded. And if it's a long SOIC chip, it's almost certain that there is no die nor bonding wires near the ends.

author: Chriss
author_rank: Frequent Contributor
timestamp: April 14, 2019, 10:48:29 am
content: Ok, I checked your diagnostic unit. I never saw that kind of diag tool but that means nothing.I repairing lot of car diag, flashing tools and make mods and reworks on them.Pleas show as the pcb so we can see how the configuration is set up on this kind of tool.What kind of cpu is in that tool?Are there any other memory parts or just the cpu and this 28F128?

author: Liteace
author_rank: Regular Contributor
timestamp: April 14, 2019, 04:48:07 pm
content: Thanks for the rapid reply guy's, much appreciated, here's front and back of main board, sorry the pic is crap that the best my phone can do, if needed download the image and zoom in.I noticed it does have another 28F128J3 on the back, in exactly the same position as the one on the front, or should I say the one that "was" on the front.There are 2 other parts, the LCD pcb and the keyboard pcb connected via ribbon cable

author: Liteace
author_rank: Regular Contributor
timestamp: April 14, 2019, 04:55:55 pm
content: Here's a pic of the damaged area, more pads fallen offI dont think the battery is needed for everyday operation, maybe it was there to just save time and date if you wanted to print a diag report

author: Chriss
author_rank: Frequent Contributor
timestamp: April 14, 2019, 10:35:41 pm
content: Huh! this is a huge problem.I would for first focus on the problematic flash memory.Somehow you must get out the content from there and use a new flash memory to write it back.Of course if that is possible due to the protection technique what that flash memory has built in.If you can't replicate the content of that flash memory than you must find a solution how to wire it up to the board.Maybe the shaving technique is the best what you can do.Of course there are some solvent on the market what can dissolve the housing of the IC but I have no experience with that.That flash memory holds something like the firmware of the whole unit I assume.The second big problem is how to stop to corrode the cooper traces?I'm pretty sure you cleaned it well but trust me, the affected cooper traces will corrode in the future and make you big problems.Honestly, I really wouldn't waste my time to repair the unit, mostly because of the corrosion.

author: quadzillatech
author_rank: Contributor
timestamp: April 15, 2019, 01:17:31 pm
content: Hi i brought an autel maxdiag fr-704,with all the software,it was about £160 gbp a few years ago,it covers most makes,maybe a cheap option for you,cheers m3-vuv.

author: Liteace
author_rank: Regular Contributor
timestamp: April 15, 2019, 04:46:26 pm
content: The reason I would like to repair this one, the software in it is just for old Jap vehicle and will talk with most if not all modules, use it a lot on Mitsubishi gearboxes, there's not a lot of diag tools that work as well as this on the Jap stuff, I do have 3 other multibrand laptop based diag tools so dont really need anotherI will have a go at a repair, I have got time, I, maybe cant make it any worse, I'll keep you updated on progressyou say:"That flash memory holds something like the firmware of the whole unit I assume"the mirrored flash mem on the other side, would that also have firmware in or different software ?Thanks for you help up to now

author: Chriss
author_rank: Frequent Contributor
timestamp: April 15, 2019, 08:13:35 pm
content: Sure, most of time all that sort of flash memory is used to hold some backup of the firmware for let say for factory reset.I would suggest you, repair your device as good as you can without the problematic flash ic and power it on.You should maybe get the error message on the screen about the flash memory ic.Maybe you can get then the best answer what that ic is holding.It could also be does de device won't turn on.However, I think you can't do anything wrong if you power on you diag tool without the problematic flash ic.

author: fzabkar
author_rank: Super Contributor
timestamp: April 18, 2019, 02:05:43 am
content: If the two flash memories are in sequential address order, then it might be possible to combine their contents into a single 64Mbit chip and then play with the CE and OE pins and the MS address bit to ensure that the two halves are selected in the correct order. I have used such a technique to replace 3 or more Commodore (microcomputer, not Holden) ROMs with a single standardEEPROMEPROM.

author: Liteace
author_rank: Regular Contributor
timestamp: April 19, 2019, 05:22:44 pm
content: Ive tried to power it up with the chip off, it does power up but nothing on screen, if the contents could be combined into a single 64Mbit chip that would be great but I would need a step by step on how to do that

author: fzabkar
author_rank: Super Contributor
timestamp: April 19, 2019, 10:43:40 pm
content: I would start by reading the chip. If you can't get consistent, valid data, then it would seem pointless to continue.I would then determine how the two chips are addressed. Are their data and address buses shared? How are their CE and OE pins wired?

author: Liteace
author_rank: Regular Contributor
timestamp: April 20, 2019, 07:45:22 pm
content: I will order tsop48 socket adapter to read the chip, that well take a little time to get here.The CE and OE pins on both sides are wired together, is that a good thing ?

author: fzabkar
author_rank: Super Contributor
timestamp: April 21, 2019, 01:26:13 am
content: Are the data and address buses wired together? Are all 3 CE pins connected together, ie is CE0 on U6 wired to CE0 on U7, and likewise for CE1 and CE2?

author: Liteace
author_rank: Regular Contributor
timestamp: April 21, 2019, 11:21:02 am
content: 1st of me being a complete idiot was looking at the wrong datasheet for pinout, I was looking at 48 pin and not 56, I now, I think, please check for me have this:I have checked, , I have:U6, chip pad 29 CE2 is connected to U7 pins 2, 21, 29, 48U6, chip pad 02 CE1 is connected to, U7 pins 2, 21, 29, 48----------------------------------------------------------------------------------------------U6, CE0, pin 14 connected 2 pin 1 of U18 (SJA1000T) at the top of U7 side of board.U7, CE0, pin 14 connected to pin 96 of U8 (A54SX08A-F) U6 side of boardI might have got this completely wrong, if I have I apologize in advance and would need help checking againThanks

author: fzabkar
author_rank: Super Contributor
timestamp: April 21, 2019, 11:04:35 pm
content: If the flash memories are under the control of different ICs, then it becomes too complicated, at least for me. Sorry.

author: Liteace
author_rank: Regular Contributor
timestamp: April 22, 2019, 06:21:04 am
content: I just knew I had done something wrongIve just had another check and the flash memories are controlled by the same chip, the U8 (A54SX08A-F) I will check pinout again after work todayThanks

author: Liteace
author_rank: Regular Contributor
timestamp: April 22, 2019, 06:22:56 pm
content: Im back on this now, I switched off mobile phone so I didn't get disturbed and I think / hope this time I have done it correctU6 CE0 is connected to pin 97 of the A54SX08AU7 CE0 is connected to pin 96 of the A54SX08ANow Ive found the 28F128J3's correct connection points can this be done ?

author: fzabkar
author_rank: Super Contributor
timestamp: April 22, 2019, 08:54:20 pm
content: Another way to approach this problem might be to piggy-back a replacement 32Mx8 flash IC onto U7 and run a separate wire from its CE0 pin to the Actel FPGA.Otherwise, using a single 64Mx8 flash IC to replace both 32Mx8 ICs would require a couple of external gates to decode the two CE0 pins into a single CE0, and the CE0 corresponding to the low order addresses would need to be connected to the MS address bit.

author: Liteace
author_rank: Regular Contributor
timestamp: April 22, 2019, 09:39:42 pm
content: So I could read U6 program another and then just piggy back ?

author: fzabkar
author_rank: Super Contributor
timestamp: April 23, 2019, 12:22:03 am
content: IIUC, the two flash ICs share all pins except CE0. This means you should be able to piggy-back all pins except CE0.BTW, I can see several open traces nearby. These would need to be repaired.

author: Liteace
author_rank: Regular Contributor
timestamp: April 23, 2019, 05:46:48 am
content: Its nice to have a trained eye helping as I am complete novice, could you point out where the open trace repairs need doingThank you