Yokogawa DL2700 No OS - Page 1
Forum section: electronics / repair

author: cattlot
author_rank: Contributor
timestamp: May 14, 2025, 09:34:13 pm
content: Hello Everyone, I recently bought a Yokogawa DL2700, it powers up but it has no os, Ive sent a request to yokogawa for a disk or file but like i feel like nothing will come from that, does anyone know how to fix this or does someone magically have the file i need for this. (Strangely looking at the service manual it doesnt seem to have a hard drive so i dont even know where the Operating system would be saved, that being said it doesnt even have this error listed so idk)it has a 3.5" floppy drive and appears to work when loaded with other disks as a message appears showing its checking the directorylink to service manual >>>https://elektrotanya.com/yokogawa_sm700820-01e_020_dl2700_oscilloscope.pdf/download.htmllink to user manual (Japanese) >>>https://cdn.tmi.yokogawa.com/IM700820-01J_040.jp.pdfAny help would be greatly appreciated, i feel very screwed as this is a scope with basically no documentation

author: m k
author_rank: Super Contributor
timestamp: May 21, 2025, 05:43:18 pm
content: Somewhere is a flash disk.With luck it's a standard removable one, and with more luck it has lost its boot info.

author: cattlot
author_rank: Contributor
timestamp: May 22, 2025, 03:10:18 pm
content: Its built onto the CPU board, its 3 intel flash chips, either it got corrupted somehow or maybe one of the chips died, i want to dump the roms when i can but because they are soldered on the PCB i need to find the time.

author: m k
author_rank: Super Contributor
timestamp: May 23, 2025, 11:20:27 am
content: Couple other things to check, battery backed setup RAM and socketed boot ROM.Turning machine on while pressing Reset key is resetting something.Are these things doing any console stuff?68k is not M$, maybe it's a Unix of some sort.

author: GGMM
author_rank: Frequent Contributor
timestamp: May 24, 2025, 04:21:01 pm
content: hello,I went through the Yokogawa site, no firmware for DL2700.Maybe we should flash? See if there are any Jtag connectors on the main board.There is a battery, check its voltage.The manual service is no more helpful than that.Expect a reply from Yokogawa (??)Product discontinued since 2004, this will not helpcdt

author: cattlot
author_rank: Contributor
timestamp: June 02, 2025, 05:30:05 pm
content: Hello,I contacted yokogawa, they said they have nothing, i even reached out to their service center.i need to look on the board for a jtag connector but how would that help? if the memory is corrupted there is not much to do, I also think the M6800 cpu on the board doesnt have it. Although on the board there is a white connector with pins directly connectected to the cpu, maybe it has a uart or something as its not plugged in normally?for the other post, pressing on the reset key does nothing, the rom chips are soldered directly on the PCB which sucks. I dont think the scope would have a CLI or use a common OS due to the weird architecture it uses (motorolla 6800 and a intel i960 on different boards), there is also nowhere to plug in a keyboardon the post i have attached pictures of the 6800 board where the roms are. its a multilayered board which makes reverse engineering hard to do, it also has an FPGA on both this and the i960 board, i think it has to do with sending data between the two cpus as the CS of the memory chips are connected to it.I also want to look at the interface board where these boards plug into and look for cracked joints or maybe issues with the connection because maybe it corroded and not making a proper connection.Thanks for your replies and i apologise for not responding as I am currently doing exams

author: GGMM
author_rank: Frequent Contributor
timestamp: June 03, 2025, 06:27:47 am
content: hello,It does not seem obvious to troubleshoot. You probably need a connector extension. Only positive point, the circuits are screen printed.Apart from testing the diodes, capacitors, resistors, no solution. And in addition no scheme.A priori no Jtag connector. Meaning of leds?Not easy...good luck

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 03, 2025, 07:27:05 am
content: I have the same oscilloscope and it works.I might be able to read the memory off a chip depending on how much effort it'll take.It is highly likely that all of the data is stored on the flash, unless there is an IDE connector on the board. I have a spectrum analyzer with a similar processor where all of the data is stored on the flash. I also have the programmer and socket for programming these. (Hopefully there isn't a SCSI hard drive)Can you identify all the flash ICs on the board? Are there any flash chips on any other boards, and is there a hard drive? (There are some oscilloscopes from that time period which have an IDE connector for the hard drive). If it is the flash IC you will need to get a programmer (I suggest the Xgecu ones) and a socket.

author: m k
author_rank: Super Contributor
timestamp: June 03, 2025, 09:08:01 am
content: Quote from: cattlot on June 02, 2025, 05:30:05 pmHave you tried GPIB?Right of GPIB controller is RTC chip.Is there a battery somewhere?There is a boot block, 2 parameter blocks and 1+3 main blocks per chip.If those can be configured more than one way somewhere must be an info of how.E,complex math.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 03, 2025, 09:51:53 am
content: the white connectors goes to ?rtc62421 datasheetupd7210 gpib controllerupd72069 is a floppy controller

author: cattlot
author_rank: Contributor
timestamp: June 03, 2025, 09:52:38 am
content: Ok so by looking on the service manual, it says that the 68k CPU board (the board i put images of before) contains the flash memory, so it means that it would be the 3 28f400bx memory IC chips right? (I attached the datasheet for the chip)I have a hot air gun, the Xgecu programmer (but it cant go in it because the IC is 44 pins) and the socket reader for it (44 pin PSOP), I can take the ics off the boards, but the problem is to read them and im worried about heating the chips and the data being corrupted.Ive also looked inside the scope there is no ide hard drive or scsi driveI havent tried GPIB, i dont think i have any of the kit nessecary to hook up to it, there is a port on the back of the scope for it though. do you think i should try it? but what would it tell me other than its not booting?Quote from: m k on June 03, 2025, 09:08:01 amHow did you find that out? By reading the chip datasheet or something else?

author: cattlot
author_rank: Contributor
timestamp: June 03, 2025, 09:57:50 am
content: They dont connect to any other device inside of the scope, the connectors are present on both CPU boards, i need to check to see what pins they are connected as i cant remember right now but i remember 3 pins were connected directly to the CPU, but at one point i hooked up a logic analyser to it and there was no activity so i dont know?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 03, 2025, 10:23:45 am
content: gpib manual translated thru onlinedoc translatororiginalhttps://cdn.tmi.yokogawa.com/IM700820-12J_040.jp.pdf

author: cattlot
author_rank: Contributor
timestamp: June 03, 2025, 11:11:36 am
content: Thanks! what site did you use to translate it?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 03, 2025, 12:21:31 pm
content: its written loll but be aware they have nags or popupsdo they load the os thru the floppy drive, like some tds3k serieshaven't checked in the gpib document, if you have some memory dump commands ...

author: m k
author_rank: Super Contributor
timestamp: June 03, 2025, 03:01:50 pm
content: Quote from: cattlot on June 03, 2025, 09:52:38 amNot much I guess.Even if you get an ID from it you're still missing all special commands.QuotePage 12 of your memory PDF.E,Lattice has a single row JTAG version.

author: GGMM
author_rank: Frequent Contributor
timestamp: June 03, 2025, 04:21:32 pm
content: hello,In the manual we talk about batteryHave you tested it?Also it seems to boot on a ROM, but is the message not misleading? Boot disk doesn’t exist? As if it was looking for a floppy?Not see configuration in service manualTo dig......before diswelding

author: GGMM
author_rank: Frequent Contributor
timestamp: June 03, 2025, 04:22:36 pm
content: or internal scsi disk???

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 04, 2025, 01:01:57 am
content: There doesn't appear to be a hard drive inside my model.I think the i960 is a red herring. The i960 is actually reset on the next screen after that boot screen.

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 04, 2025, 01:16:43 am
content: Here is a video of what happens to the debug LEDs when the machine boots up.I have also taken the machine apart and there is no floppy or hard drive inside. It looks like the interface board is likely to blame, particularly the ROM.What you might want to do is back up all the data on the ROMs first. Then see if you can "test" the memory by writing 0s and then writing Fs.

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 07:00:31 am
content: Woah Ok thats interesting, I thought the 3 beeps was an error code but its not, whats different with my machine is that the last LED does not clear when it boots.Ok so i will desolder the roms and read the data out when i can (or maybe i can find a chip clip). I think you are right about the i960, it doesnt even boot with it not plugged inso i think if there were issues with it the whole machine would not bootthanks dudeAlso yes i did check the battery, the battery is working. The osciloscopecouldbe connected to a enternal scsi disk but that was just to store waveforms, all the boot and operating system information is stored in flash.In the manual there is nothing about memory dumping so i think its a dead end which is unfortunate.I think the reason its asking for a boot disk is because yokogawa at some point probably had a recovery disk for the osciloscope and it was just the machinine's way of asking for it.Thanks for your replies

author: m k
author_rank: Super Contributor
timestamp: June 04, 2025, 10:09:44 am
content: Quote from: cattlot on June 04, 2025, 07:00:31 amIs the battery rechargeable?When you are dismantling the machine you're also disconnecting that battery from other boards.So don't desolder anything before you know that there is no battery backed setup memory.QuoteHave you ever seen a computer without an operating system?There's a boot order.If no boot device is found, the message is what your machine is showing, it is not an error.When you insert a floppy the machine start checking if it can boot from there.

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 10:25:53 am
content: All boot memory on the board is intel flash chips, they are non volitile, its a common thing of yokogawa gear from this generation is that when the battery dies the only thing that is lost is saved waveforms and the clock, why would it be any different on the dl2700?The Scopeislooking for a disk but we dont have what it needs, it doesnt run any normal operating system as its custom built by yokkogawa, when i load in a floppy it tries to read it and says its missing the proper directory, probably a recovery file.by looking at the firmware that is avaliable for the other scopes such as the dl750 which has data loaded by a floppy, its probably looking for one of these files but specific for the 2700, the problem is that the firmware avaliable online is for the newer generation of yokogawa scopes that are not based on the M6800 (instead it is a 32 bit risc cpu), so anything we could get from it is probably not helpful.if we couldmaybefind firmware of the scopes from the same generation like the dl1540/20 maybe we could modify it to work but thats alot of workThat being said, i have attached the dl750 firmware as reading up on it, it does say that its firmware was based of the 2700 but it looks like its compressed or encrypted and i dont really have the technical skills to do that let alone port it to a different architecure

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 04, 2025, 04:12:02 pm
content: Quote from: m k on June 04, 2025, 10:09:44 amThe backup battery doesn't do anything important. The machine also still works after I removed the interface board and put it back.

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 04:15:51 pm
content: yeah that makes sense. Also its interesting that your board doesnt have any of the bodges that are on my board? has someone fixed by board? or was there a design problem

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 04:25:14 pm
content: Eggert,Only for information is it possible to have picture of the battery and video of the starting...only curiosityno solution at this time for mecdt

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 04:26:21 pm
content: Also for reading the flash, i mentioned that there might be a problem with me reading it as it is 44 pins, reading into the datasheet it does mention that its compatable with the 40 pin rom pinout by excluding some of the pins, the 4 pins that are missed out are just for writing to the flash so could I just leave them disconnected?

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 04:29:54 pm
content: Heres the battery, its an absolute pain to remove from the machine

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 04:40:18 pm
content: re,thank's for the picture. You have tested it. 3.6v?other:somebody known the utility of the white connector on the cpu board?The unit appears to start and displays an error message.So it seems to start charging the flash, find an error (soft or material?) I think.How can I be sure that the flash is corrupted?No doubt, but please check everything that is possible on all cards.I had the case of a corrupted flash on a rigol, it booted at first, but then the screen was completely zebra.here, It seems too "clean".I have this feeling that it’s elsewhere but it’s just a feelingif you want to read the flash, be careful...cdt

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 04:55:02 pm
content: You make a good point, maybe it could be something else.the battery is at 3.3v, its a bit low but i really dont think changing it will help,maybe it could be an issue with the motherboard as all the boards connect there (diagram below),I think the CPU boards do talk to eachother as without both boards it does not boot or show signs of life, but that doesnt mean that there arent other issues on the board and you are right that its very risky to desolder chips and try to read themAlso I dont know what the connectors are for, there are 5 data pins connected to it but it goes through some other logic, i was wrong about it being directly connected to the cpu, when power is on they pull high to 5v

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:14:22 pm
content: Re,i download the user manual.see codes error, see tab 14 also...I looked on the net pictures of dl2700.there is a floppy disk drive (no disk input lol)can you confirm with picture your.see error codes on user manualPlease confirm that it is your device that was working well and now down. This is not a recovery purchase.too strange itcdt

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:15:11 pm
content: user manual

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 05:21:21 pm
content: You have the wrong manual, thats the 7200 not the 2700, I think i might have put the wrong one up, I only have a japanese manual that i found online.There is no error codes just what that showsI purchased it working but with no returns accepted, the guy told me on ebay he bought it from a closing lab, i kinda got scammed but like i might aswell try fix it

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:22:09 pm
content: Sorry!!error it's dl7200 user manual!!!!but there is a floppy normaly!cdt

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 05:23:48 pm
content: yes, mine has a floppy drive too, I just dont have the software it wants, it tries to load the software, when it cant find it, it errors out

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:27:42 pm
content: Re,you mean it worked when you had it, or you had it with this problem? It's not the same.cdt

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 05:28:50 pm
content: When it arrived it was not working.

author: GGMM
author_rank: Frequent Contributor
timestamp: June 04, 2025, 05:43:51 pm
content: re,So when it came in, it wasn’t working.At least it’s clear and we know where we’re starting.You’re talking about loading...Is there a floppy disk in the drive?If so, what is indicated on it.Start without floppy to see.The ideal is to make a video of the start...These are silly questions... LOLnb if you have a floppy disk, can see files on a PC (Think is not a standard boot )cdt

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 05:46:04 pm
content: To be clear, this did not come with a floppy disk, i have them laying around and i put a known good one in. I can send both a video with and without a disk.

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 06:02:00 pm
content: Here are the videos, they are too large to upload here, they are on a google drivehttps://drive.google.com/drive/folders/1505-DaJBFncHYb3w0_bN3xxxwhnTiDgC?usp=drive_link

author: m k
author_rank: Super Contributor
timestamp: June 04, 2025, 06:29:43 pm
content: Quote from: cattlot on June 04, 2025, 10:25:53 amVery small parts of disk images are almost something, still practically useless.Included PDF has that for System Update Utility you must hold a shift key down when turning the machine on.It indicates that without a shift there can be a different disk operation.Some machines are saving their initial software versions.68k board has a backup RAM, it is also marked as different than flash RAM, but there are no other nonvolatile memory chips.So if one is for backup, two others can still be for old and new OS versions, but is a single 500k chip enough for the whole thing.Quote from: cattlot on June 04, 2025, 04:26:21 pmCMOS doesn't like floating pins, but 40 pin connection is doable.Pin 44(RP#) is Reset/Power_Down and must be high for all operations.Low means deep power down mode.

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 08:12:23 pm
content: Quote from: m k on June 04, 2025, 06:29:43 pmYeah ok i thought so, imma need to remember to do that thoQuote from: m k on June 04, 2025, 06:29:43 pmI dont really think so, I think that all 3 chips are used as the main OS, maybe one chip for the M6800 and the other two for i960? thats what i think it is and i dont really have any proof of it so who knows.Maybe the backup ram is just ram thats kept by the 3.6v battery?

author: cattlot
author_rank: Contributor
timestamp: June 04, 2025, 08:19:45 pm
content: For the white connector, I dont really know what it is, the pinout is the same for both boards.Ive attached a logic analyser to both boards and there is no activity on any of them, i havent followed the traces of the 'D' pins to see where they end up, do you think its worth it to look into the actual pinout or idkAlso something else strange is that I think the clock for the 6800 is generated on the i960 board? because powering on the m6800 by itself the cpu has no clock

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 05, 2025, 12:35:40 am
content: I can confirm that my working scope has no floppy disk too.

author: Kean
author_rank: Unknown
timestamp: June 05, 2025, 03:34:36 am
content: Quote from: EggertEnjoyer123 on June 05, 2025, 12:35:40 amI wonder if in the previously mentioned "System Update Utility" there is any options for a backup of flash to floppy...Seems unlikely, but worth a check if you can. Else, the only source of boot floppies would be Yokogama (i.e. nonexistant).

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 06:45:21 am
content: re,I don’t see Yokogawa unsoldering the flash chips to reload a firmware!!There is probably another solution. This white connector is intriguing especially if there is no connection.Do not forget that this oscilloscope must have been "tinkered"Make a map of the connections on the white connector.the tracks can be followed. watch if they go to uart.Verify that the ports at the back are coming on "hard", it can be soldered directly to an extension cardIs there a serial port (I do not believe a USB present) try to communicate.These are only ideas.You would need a former Yokogawa technician to give you information on this forumBe sure to contact them with a good explanationNot seen too much YOKOGAWA forum on this topic.cdt

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 05, 2025, 06:52:15 am
content: Quote from: Kean on June 05, 2025, 03:34:36 amThe floppy with an image from that zip file doesn't boot.Perhaps there is a GPIB command for getting the flash data off the device?Quote from: GGMM on June 05, 2025, 06:45:21 amThe white connector is unconnected on my board. There might be something funny going on with the DIP switch on the CPU board though.

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 06:53:53 am
content: re,when i repair my DL1640 Yoko, I had downloading many thingssee if it exists for a DL2700 or otherdon’t forget the picture of the floppy toosome exemples in pjyou have to found the soft for DL2700cdt

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 07:14:52 am
content: Re,what it this file on floppy disk. Zip file??may you put all files of the disk floppyto seecdt

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: June 05, 2025, 07:16:07 am
content: Did you contact their American office by the way?Might be worth a shot to try contacting their Japanese office (which is probably where the scope was designed anyways).Quote from: GGMM on June 05, 2025, 07:14:52 amSorry, I wasn't clear. I wrote a floppy with the first image and the scope got to the "Hard Reset i960" page. It then tried executing the code on the floppy and it said "Error 646" for a few seconds, and then it just went to the scope screen.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 05, 2025, 07:33:28 am
content: i'm registred at yokogawa, and believe me : all their ressources pages or the only mentions about DL2700 ends up with discontinued, and no files to download, still some infos papers, but nothing to help your caseit is either find a donor / part, dump from a working one and know how to ? without destroying it ...try to find yokogawa groups/forums if there anysell it for parts ...sorry and you have posted on reddit and others and got no answer(s) .......you have a yokogawa t&m guy here : Yokogawa TM UK but not active from 1 year and he's Tests and Measurement team ?

author: m k
author_rank: Super Contributor
timestamp: June 05, 2025, 07:38:03 am
content: Quote from: cattlot on June 04, 2025, 08:19:45 pmLattice ispDOWNLOAD?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 05, 2025, 07:45:43 am
content: a matter of knowing where the white connector pins goes ...

author: cattlot
author_rank: Contributor
timestamp: June 05, 2025, 08:46:11 am
content: Quote from: EggertEnjoyer123 on June 05, 2025, 06:52:15 amThe dip switch's use is defined in the service manual, it looks like its nothing usefullQuote from: coromonadalix on June 05, 2025, 07:33:28 amyeah thats what im thinking, these scopes are rare though but like i can wait to see one pop upQuote from: m k on June 05, 2025, 07:38:03 ammaybe? both boards do have FPGAs, i will find out what its used for.I do still want to desolder the chips from my board and read them, maybe I can do a checksum of the bytes and compare it with the one that Eggert's scope showed at boot? what are the risks of doing that? is it just that like the pads might come off?Is there not a chip clip for 44-Lead PSOP? that i can just pop onto it?I have contacted yokogawa about it, there is nothing left unfortunatly, no amount of begging will change that.Quote from: coromonadalix on June 05, 2025, 07:33:28 amTests and Measurement is the team that deals with osciloscopes i think right?

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 10:06:20 am
content: re,some help herehttps://www.eevblog.com/forum/testgear/all-things-yokogawa-tm/cdt

author: cattlot
author_rank: Contributor
timestamp: June 05, 2025, 10:07:41 am
content: its the same guy i talked to at yokogawa, is there just one guy working in the uk?

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 03:22:02 pm
content: Eggert,may you explain this. how you wrote on floppy disk?how you do? Not clear for meit's image of a DL2700?"Sorry, I wasn't clear. I wrote a floppy with the first image and the scope got to the "Hard Reset i960" page. It then tried executing the code on the floppy and it said "Error 646" for a few seconds, and then it just went to the scope screen."you go in a secret fonction (F2 at boot or other?)For me err 646 is pb medium (on list of error on a DL1640)--->>> 646 to 653 Storage media failure. Check the mediumcdt

author: m k
author_rank: Super Contributor
timestamp: June 05, 2025, 05:17:31 pm
content: Quote from: cattlot on June 05, 2025, 08:46:11 amIt's like any desoldering operation, same with risks.So interface board ROM/RAM check text comes first.Then boot ROM version.Then the actual boot or disk missing, or floppy access.i960 stuff comes later.My guess is still so that flash is not a single block.DOS 6.22 was less than 150k, command interpreter included.Pin 14 of flash chip is OE#, scope them all.If all goes down you can be sure that all are accessed at least once.Maybe GPIB can be something.Earlier communication manual has a File Group with many commands.Interface board is also first in line, so maybe GPIB is active.Quote44 pin chip clip seems to be missing.And even if you find one you may not like its price.

author: GGMM
author_rank: Frequent Contributor
timestamp: June 05, 2025, 06:28:08 pm
content: re,the ideal would be to have a function like here...try??cdt

author: m k
author_rank: Super Contributor
timestamp: June 07, 2025, 02:15:38 pm
content: Quote from: cattlot on June 05, 2025, 08:46:11 amFor light version with less work you can put U8 to sleep, lift pin 44(RP#) up and connect it to GND.Middle chip so that it is least likely first and containing boot code.Since first text is interface board ROM/RAM check you should see a change.