Electronics > Repair
TDS3014 adventures
james_s:
I don't sell them, I just don't have time to be doing production, especially not for esoteric things like that where the component cost is high and the sales volume likely just a handful of units per year. They are trivial to build though, there is nothing on the board besides the Dallas chip, some headers and a decoupling capacitor that is probably not even really necessary.
sicco:
How about we design a board that fits into the expansion slot and has the new SMD DS1744W on it, plus maybe the serial port DB9, the VGA connector, maybe a Bluetooth serial, maybe also a Lantronix Ethernet/WiFi to serial module, and maybe a FTDI USB chip or TTL adapter pin row?
The expansion connector seems to have all of the address and databus lines that the DW1742W has. I guess the /CS for the DS1742W is just a selection on a memory bank from the remaining A12..A19 lines. And I guess a ‘dead battery’ (or an ‘over-Dremelled’) DS1742W simply will not get active anymore on the tri state databus. So maybe we can do a Kicad board that not only fixes a dead RTC battery TDS3000 TDS3012, TDS3014, TDS3034, TDS3054 etc etc scope without even opening the case, without soldering, but also gets an affordable Serial interface as a bonus? Serial port as per what’s reverse engineered elsewhere on forum, 74AC245 etc.
With all info on that expansion port on the www fora, this looks like feasible?
Anyone any thoughts? Commercially viable? Guess there must be 1000nds of otherwise perfect but 15-25 years old / dying / dead units that can get a second life for another decade or two?
james_s:
You'd still have to remove the dead DS1742W, it wouldn't magically stop functioning and tristate with a dead battery, it will just be full of random garbage each time you power up. I don't know if the entire address space is accessible from the expansion connector, if it is then something like this might be feasible but it's likely to be quite a complex project. The cartridge shell is probably a good candidate for 3D printing.
sicco:
Let’s find out if the DS1742 does or does not tri state when battery is dead. Really dead i mean. Not just no longer ticking the clock, but also no longer NVRAM persistence. Reason why I suspect it would go tri state always with a really dead battery is that others mentioned that it does not matter what’s in them: garbage, zeros, whatever. If it has good VDD, but really dead battery, one would expect that the scope finishes booting instead of doing only Tek welcome screen, one relay click, one second of floppy drive activity, and then nothing. But I think it does not do that. So...
Anyway, worst case if it does still output data, we’d need to destroy only a few pins of an old DS1742W, like its VDD, or pull high /CS or /OE. I’d even dare a short wire bridge from VDD to /CS. Easier still than de-solder 24 pins, without any mainboard pcb damage.
james_s:
--- Quote from: sicco on October 08, 2020, 10:47:16 am ---Let’s find out if the DS1742 does or does not tri state when battery is dead. Really dead i mean. Not just no longer ticking the clock, but also no longer NVRAM persistence. Reason why I suspect it would go tri state always with a really dead battery is that others mentioned that it does not matter what’s in them: garbage, zeros, whatever. If it has good VDD, but really dead battery, one would expect that the scope finishes booting instead of doing only Tek welcome screen, one relay click, one second of floppy drive activity, and then nothing. But I think it does not do that. So...
Anyway, worst case if it does still output data, we’d need to destroy only a few pins of an old DS1742W, like its VDD, or pull high /CS or /OE. I’d even dare a short wire bridge from VDD to /CS. Easier still than de-solder 24 pins, without any mainboard pcb damage.
--- End quote ---
It does not, this is already known. The device continues to function normally except it powers up in an unknown state, usually FF in all RAM cells. I have modified several of them to use an external battery and had one develop a faulty connection so the battery was not connected at all. When power is applied the only change is that the battery flag bit is set indicating a faulty battery, all other functions appear normal. Desoldering 24 pins is trivial if you have proper equipment, I can remove one of those ICs in less than 5 minutes without damaging the board. .
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