TDS-524A NVRAM backup

Questions in this forum area are community supported. Tektronix does not regularly monitor posts in this area.
t_staton@msn.com
Posts: 2
Joined: March 17th, 2017, 6:37 am
Country: United States

TDS-524A NVRAM backup

Postby t_staton@msn.com » March 17th, 2017, 6:50 am

I have a TDS-524A in excellent condition. Everything is working well and it was last calibrated a couple of years ago. I have read that it is wise to replace the electrolytic capacitors that are prone to leakage. I will definitely do that. I have also read that it is wise to back up the NV RAM in the Dallas DS1650Y chip. Mine has a date code of 9317U. I assume that means 1993? 27 years!
What is the best way to back up the NV RAM? Is it safe to remove it so it can be duplicated using a ROM programmer? I heard of instances where removing it corrupted it. I have heard that it is possible to read the contents without removing the chip, either through the GPIB port or the console port. Details of either seem to be missing form the site. It looks like some older posts have gone missing.
I presently don't have a ROM programmer, GPIB adapter, or Console port adapter, so whichever path I take I will have to purchase or fab some hardware.
Any suggestions would be appreciated.

Terry

strick
Posts: 14
Joined: March 22nd, 2016, 11:23 am
Country: United States

Re: TDS-524A NVRAM backup

Postby strick » March 19th, 2017, 6:26 pm

Terry,
If your surface mount capacitors (smc) haven't leaked yet, you are truly blessed. Once it happens, it will wreak your machine. Cap is the real expert on replacing and if you do a search on the board for his posts, you will get the info. I've only done 800 or so smc replacements and only over the past 3 years, so I'm a relative newbie.

The DS1650Y chips are available on ebay from China and occasionally the states. I don't believe that they are still produced by Dallas or Maxim, but some folks that I've bought from are refurbishing them and putting a 2016 date stamp (9317U does mean 1993...) on em. Nevertheless, the refurbished ones seem to work as well as the original ones produced in 2009 or so, when they were still being made.

To back up the NVRAM, you can remove the chip (I use a high-powered vacuum solder sucker), replace with a socket and and then read the NVRAM with a rom reader/programmer. If you get the chip too hot, it will scramble the memory and reading it is useless.

I use the software tool "tektool.exe" that can be found in the forums and other places to get the image before I try to get the chip off. From memory, the image starts at location 0x4000000 and is 0x80000 bytes (Hex) long (512k). This image is then written (I use a GQ-3X programmer) back to the new chip and installed.

If you have more questions, you can send me a PM and I'll be happy to answer. BTW, I have NVRAM images for the 520A, 540A, 544A, 540C, 520D, 744/784A, and 640/644A. If you brick your unit, my 520A image will probably work.

Strick

t_staton@msn.com
Posts: 2
Joined: March 17th, 2017, 6:37 am
Country: United States

Re: TDS-524A NVRAM backup

Postby t_staton@msn.com » March 20th, 2017, 5:43 pm

Thanks strick.
Interesting to hear that someone is rebuilding the DS1650 and selling them with newer date codes. I saw those when I was looking for chips but figured they must be counterfeit chips. I ordered some with a 0802J date code, but maybe I'll see about something newer.
I will wait until I have re-capped and cleaned before I power it up again. Then I will try connecting the console port to the UART board as some have done. I hope to be able to read the NV RAM contents that way before removing the chip and using a ROM programmer to duplicate it.

Terry

strick
Posts: 14
Joined: March 22nd, 2016, 11:23 am
Country: United States

Re: TDS-524A NVRAM backup

Postby strick » March 21st, 2017, 2:11 pm

I built one of the serial debug connections using the option 13 card and use it for monitoring power on self tests and SPC. Gives a lot more info than the simple diagnostics for finding and fixing problems. However, I've never tried to use it to give commands. I'll give that a try this evening and see if any of the TDS460 commands do anything to a 640A that has a failed ACQ board. I'm a little concerned about using it on anything that works as Cap indicated that this port had full access and could brick the scope. The Tektool utility has safeguards built in that help to keep you from ruining the board.

Anyhow, good luck and I'll let you know if I figure out how to read anything with the serial port on the 5-700 series.
Strick

fenugrec
Posts: 14
Joined: January 18th, 2017, 3:51 pm
Country: Canada

Re: TDS-524A NVRAM backup

Postby fenugrec » March 21st, 2017, 4:17 pm

strick wrote:I built one of the serial debug connections using the option 13 card and use it for monitoring power on self tests and SPC. Gives a lot more info than the simple diagnostics for finding and fixing problems. However, I've never tried to use it to give commands.


Funny you should mention this now, I spend last evening playing with the service console on my TDS744A.

Some info on reusing the option 13 card (RS232+parallel) for the service console:
viewtopic.php?t=138100
viewtopic.php?f=568&t=138489&p=280292
viewtopic.php?f=568&t=137307

I use the "corrected pinout " from this post
viewtopic.php?f=568&t=137307&start=20#p279787
which is mostly the same except 1-2 signals, I forget which.

On the TDS744A I need to have RTS/CTS flow control enabled, or just bridge the two pins together, otherwise the scope doesn't boot.

As Strick and others say, you can probably brick your scope very easily and efficiently from this mode. There are no safeguards; you can execute pretty much any of the ~ 4000 visible functions.

A few relatively safe commands that work on my 744A:
libManagerWordAt
d
readAddr
readByteAddr
readFromAddress
HWADumpOptValues
HWADumpSysValues
HWADumpCpuValues
scopeErrorLogDumpToConsole
scopeErrorLogClear


I haven't seen any utility to dump NVRAM through the service port, Strick are you aware of one ? (tektool is only GPIB I think) Otherwise I could write one fairly easily; only issue I have is the addresses aren't always the same when you read via GPIB vs the service port. And I don't think I have a sample NVRAM dump to compare to, so my confidence level is not very high.

strick
Posts: 14
Joined: March 22nd, 2016, 11:23 am
Country: United States

Re: TDS-524A NVRAM backup

Postby strick » March 21st, 2017, 6:37 pm

Well, I just did a check on my defunct 640A. I dumped the contents of the NVram (0x4000000) using Tektool, and then used the serial debug port that is well discussed here. Typing help gave the same commands as shown for the TDS400 series. I dumped the first 1000 and compared it to the Tektool dump and they are the same. I have not done an exhaustive (512 Kbyte) check, but if the first is the same, I'm pretty sure it's as good a way as Tektool. All you have to do is use a serial dump program and dump the data to a binary file for a loader to access. I'll give it a try on one of my (many) old DS1650s and let you know how it works.

More importantly, I suspect you can write to memory directly with the serial tool. I would love to be able to reflash some flash memory that is corrupted on a couple of boards that I have. Tektool was written for a flash that uses 16 byte path (28F016, I think) vice the 8 byte path of the 28F008 that I see in most of my boards.

Anyway, it's looks like it's another way to get the NVram data, if you don't have a GPIB setup.

Strick

emalju
Posts: 3
Joined: March 20th, 2017, 8:25 am
Country: Spain

Re: TDS-524A NVRAM backup

Postby emalju » March 22nd, 2017, 11:43 am

Strick, Hi

I have a TDS544A Version: FV: v3.8.4e and I am trying to fix the bug:

ERROR: diagnostic test failure, nvLibrariansDiag, Libs with crcc failures:, ExtConst
ERROR: diagnostic test failure, extended cal librarian reset

Would it be possible to fix this fault by reprogramming the NVRAM?

Do you have a suitable image for me to compare with a dump by console or GPIB?

Any ideas will be welcome.

Best regards.

strick
Posts: 14
Joined: March 22nd, 2016, 11:23 am
Country: United States

Re: TDS-524A NVRAM backup

Postby strick » March 23rd, 2017, 7:36 am

Emalju,
As a matter of fact, my "test-case" TDS520A started throwing those exact error messages last weekend. I had not bothered to change out the DS1650Y yet as I never intended to pass the scope on to anyone. I pulled the chip, put in a socket and reprogrammed a new DS1650Y with a known good image. The scope then booted properly without that error message. However, I lost the 2F option that I had programmed using the gpib earlier. Let me check my TDS540A version and I can send you a good NVram image via direct email. I don't think I have a 544A image, as my color scopes have been 744As and a 644A.

You can send me your direct email address via PM unless you want everybody to know it... :)

If you have a gpib connection, you can easily reset any options that get lost.

Strick

emalju
Posts: 3
Joined: March 20th, 2017, 8:25 am
Country: Spain

Re: TDS-524A NVRAM backup

Postby emalju » March 23rd, 2017, 1:18 pm

strick wrote:Emalju,
As a matter of fact, my "test-case" TDS520A started throwing those exact error messages last weekend. I had not bothered to change out the DS1650Y yet as I never intended to pass the scope on to anyone. I pulled the chip, put in a socket and reprogrammed a new DS1650Y with a known good image. The scope then booted properly without that error message. However, I lost the 2F option that I had programmed using the gpib earlier. Let me check my TDS540A version and I can send you a good NVram image via direct email. I don't think I have a 544A image, as my color scopes have been 744As and a 644A.

You can send me your direct email address via PM unless you want everybody to know it... :)

If you have a gpib connection, you can easily reset any options that get lost.

Strick

Thanks for answer so soon.
Actually I'm newbaby here :oops: and I still can not send PM.
Try to send me a PM and I will provide my mail by that means.
Thank you.

emalju
Posts: 3
Joined: March 20th, 2017, 8:25 am
Country: Spain

Re: TDS-524A NVRAM backup

Postby emalju » March 24th, 2017, 6:09 am

strick wrote:Well, I just did a check on my defunct 640A. I dumped the contents of the NVram (0x4000000) using Tektool, and then used the serial debug port that is well discussed here. Typing help gave the same commands as shown for the TDS400 series. I dumped the first 1000 and compared it to the Tektool dump and they are the same. I have not done an exhaustive (512 Kbyte) check, but if the first is the same, I'm pretty sure it's as good a way as Tektool. All you have to do is use a serial dump program and dump the data to a binary file for a loader to access. I'll give it a try on one of my (many) old DS1650s and let you know how it works.

More importantly, I suspect you can write to memory directly with the serial tool. I would love to be able to reflash some flash memory that is corrupted on a couple of boards that I have. Tektool was written for a flash that uses 16 byte path (28F016, I think) vice the 8 byte path of the 28F008 that I see in most of my boards.

Anyway, it's looks like it's another way to get the NVram data, if you don't have a GPIB setup.

Strick


What configuration do you use with tektool?
OS is DOS, W98,..? Card GPIB is ISA, PCI, PCMCIA or USB? Must be N.I.?
There is no tektool compiled for USB and Windows 7?

Emilio


Return to “Other or Discontinued Oscilloscopes”

Who is online

Users browsing this forum: No registered users and 5 guests