| Electronics > Repair |
| TDS3052 stuck at splash screen |
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| tom66:
All FF in the NVRAM chip likely means factory calibration and configuration was lost. It would need to be restored somehow, probably by referring to the calibration manual. Not sure how the model number can be restored, hopefully someone has reverse engineered what bytes do what. |
| sicco:
The model number is stored if flash, not in the DS1742W. The calibration is also in flash. Both are files, stored in some obscure VxWorks flash file system. Maybe you broke some PCB traces (from flash roms to XPC860) while desoldering the DS1742W? Looks like writing to flash no longer works. Quite well possible that by now you will need to reflash the roms, and reload the ds1742w with proper data. Can be done over BDM. Possibly you ended up with random data in the DS1742W that somehow suggests that it’s a 4 channel unit. First step: there’s diagnostic start up data on a ttl level serial stream at 38400 baud, on a pin on the 100 pin expansion connector. Explained elsewhere. That may tell you something. See also https://www.eevblog.com/forum/repair/tektronix-tds3012b-repair-help-needed/ |
| meduza:
Thanks. Do you know, if SPC calibration stored in flash too? Does the firmware stored in the same flash as model ID and calibration? It's strange that the scope boots (so the firmware is loaded), but somehow changed its model name and SPC loses after reboot. What even more strange, why SPC fixes noise, but doesn't fix DC offsets, but finishes with a successful message. |
| sicco:
SPC calibration result, when it's a pass, is stored in flash I think. Possibly some of it ends up in the MM9595 also. Flash for a TDS3000-no suffix and TDS3000B model is two AM29LV160 chips. They have 16 bits data bus, the CPU has 32, so that's why two. The -c models have 32 bits wide data bus flash chip, S29AL032D04. First try to load a known good binary image in your DS1742W, using a common suitable EPROM programmer. Experiment with all-zeros and all 0xff. Does your RTC actually tick seconds or is it static? Can you set the time/date to the correct time? And try to capture the boot log as per previous post. |
| meduza:
Finally, I found some time to continue troubleshooting the scope. I've found that pins 11 (WE#) of two AM29LV160B are not connected together. Can anybody check if they must be connected? Thanks. I also tested my NVRAM chip separately, it works fine in reading/writing zeros, ones, and random data. Clock is ticking. |
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