Our 3423 while old is in good shape, and has been back to Pico for refurb (USB socket poor connection + 1 channel BNC/something else replaced - so general workshop wear and tear type things) about 18-24months ago, but we've always had, before the refurb, and straight afterwards ... and continued to have problems with symptoms ranging from:
1. getting no input at all from connected BNC's
2. Odd input (ie 8v from known and proven 12-14v)
3. Heavy noise
4. Some channels working (possibly not correctly, but getting input) other flat lining
It's almost always (and hard to remember, as never tried to correlate) when we start with the first job, ie rarely, if ever, can I remember the issue being introduced during a session.
Usually unplugging the USB (2 different PICO high quality cables), use any of the 4 usb 2.0 ports on the laptop (not a hub), or restarting the software resolves it, other times a reboot of the laptop (always running on mains power), is needed. Laptops identical except 1 has WinXPx86 (usual one that causes issues - but used for pico 99% of the time) and Win7 x64 (hard to know if this has ever had the issue, as it's used so infrequently for scope work).
So with the USB Lead disconnect issue / Crashing we've had recently, we have been a little more attentive in the "start up strange behaviour" observation department!
I'm not sure if this can make a difference, but we often plug the BNC's and connect them to the Car BEFORE plugging the USB cable in. Could this be a cause? Should we plug the USB in first? Can it make any difference?
On Saturday, we connected up to an alternator, and ChA on battery +/- was giving only 8 volts, but volt meter showed 14.1v, ChB was amp clamp, but very noisy but close to Zero, ChC was AC ripple and very noisy. Unplugged USB, rebooted just Pico, reconnected USB (BNC's remained connected) and it was working fine. It was the first Pcio task of the day, but the laptop might have been on for 4hours to 3days.
Is there some problem that was missed at the last refurb? Is this a known set of problems? Is this a Scope/Laptop/Software Issue?
While we've realised and know how to work around it (and it's become so second nature we've forgotten it's a problem!), the Saturday issue made me thing it's time to raise the matter.
Richard Lukins, with an old scope, but none the less an invaluable asset!