On Tue, Oct 2, 2018 at 09:52 AM, Sergey Kubushyn wrote:
On Mon, 1 Oct 2018, jmtfungus via Groups.Io wrote:
TEST 4 FAIL 10 is nothing to worry about -- it is dead battery in Dallas
NVRAM chip. You'll have to replace it with a new NVRAM (buy it from DigiKey
or Mouser, not from Ebay so you'll get a really fresh one, not something at
the end of its life) or, better yet, with FRAM and recalibrate.
But would this not mean a total RECAL of the entire scope will be required, which is far from being an easy procedure, or not exactly cheap if sent to a third party accredited cal lab. Most people will not even have the proper equipment in-house to make most calibration adjustments, and even so its a complicated lengthy procedure. You made it sound almost like a routine issue, so I felt this needed to get the proper attention and definitively be weighted into the whole initial cost of acquisition deal. Sure he could get an image of the NVRAM from another similar scope to get this one going again, to maybe be in the ballpark, and then go on from there. But does anyone really want to have one of these top tier scopes sitting on your bench with an accuracy that is just so-so there?
Not to discourage anyone, or implying I am an expert, which I am not but I've read quite a bit about the fears and consequences of lost calibration standards. I have myself been looking around for a 2465x for a while, and although there are procedures to save the NVRAM data from a dying on-chip battery before its lost, and write it to a new chip, it still can be a crap-shoot. But if the data is already lost, all odds are off. So I've tended to stay away from cheap deals listed as "for parts only, tested to power up" and no screen shots of live traces on pictures, or any mention of error codes. I am even considering sticking to the pre 50K serial number B scopes which I understand where still build with through-hole components and have a separate Lithium battery to backup the cal standards.
