I saw with a quick comparison of the photo of the pcb 9.14 and 9.15 - circled in red
That seems to be a MICRONE SOT23-5 package IC. Probably an additional power supply regulator.
It is hard to tell as the pictures, despite being large files, do not show the IC labels in clear detail, although the MICRONE logo is visible on this specific IC.
jebem, went through the microcircuit with a white marker, then erased the marker. did on occasion on a cheap microscope. EVERYTHING FOR SCIENCE!
Yap, that is the MICRONE logo printed on the chip for sure.
Thanks for sharing the new v9.15 PCB.
The reference "S7UF" can't be found on the usual SMC Codes websites, although several LDO regulators from other manufacturers do use the SMD code "S7", so this one is likely a LDO regulator as well.
By looking to the PCB traces, this seems to be a textbook implementation following the MICRONIC LDO datasheet (see the ME6211 series for instance).
Pin 1 (Vin) and 3 (CE) are shorted together, and they are connected to the common Pwr_On supply voltage where all the other Positive Supply LDO regulators are also connected.
Pin 5 (Vout) also shows a filter capacitor in parallel, as expected.
I counted six Positive and three Negative Supply voltages in the version v9.14.
So this seems to be an additional +V supply to further decouple one more circuit in this new v9.15 oscilloscope.
By looking to the PCB traces in the photos, I can't figure out where this output voltage is going to.
To find out what is the output voltage of this LDO regulator it would required a measurement at pin 5.
Then a continuity test between pin 5 and the IC's pins around it, would reveal what IC circuit is being fed by this new LDO regulator.
So, in this v9.15 they decided to further decouple the +V supply voltage of one of the IC's that in v9.14 was using a shared +V supply voltage.
Most likely someone noted some kind of interference on specific setting/operation and the manufacturer considered this serious enough to redesign the circuit to further split one of the +V supply lines to eliminate supply line issues.