Am 23.03.2017 um 10:59 schrieb H. Nikolaus Schaller hns@goldelico.com:
Hi,
Am 23.03.2017 um 09:49 schrieb Matthijs van Duin matthijsvanduin@gmail.com:
On 23 March 2017 at 07:10, H. Nikolaus Schaller hns@goldelico.com wrote: Yes, that is the fix. Remove R2607 and make R2606 a 0R.
Wrong resistors. That's for VBAT, not VBUS.
Ah, yes. You are right. Maybe I did the same mistake as when I applied the fixes... To forget that R2605 must change the value.
Or I did fix it only in some CPU boards and the design data for V5.2 and forgot about fixing it in the CPU boards handed out to ED.
That is what the latest schematics and BOM given to GC says.
It has been fixed for V5.2 and is in the V5.2 BOM as 0R.
The 5.1 schematics show R2603 crossed out, but R2605 is still 100K.
Should be and is 0R in V5.2 schematics.
here is the page how it is for V5.2:
Can you show where R2605 is located?
I have measured several CPU boards I have here. Some have 0R and some have 100k.
And I managed to test VBUS on 0R boards only.
So there is an unknown percentage of the 30 CPU boards we have built last time which is missing this known fix and hence reports wrong VBUS and makes other trouble.
(Even better would be a PDF of both sides of the pcb, also so I know where to find stuff if I want to measure something)
I usually give the raw file directly to the Fab. And they use the coordinates to program their pick&place, i.e. they rarely need a placement plan.
I don't have exactly documented that for the exact PCB you have in your hands. To find out I would have to match e-mails about sending production data with my git.
I could easily generate a PDF for the latest design data (V5.2) but that would deviate sometimes.
So here is a photo where the R2605 is (apparently a board where it is not fixed or you would see solder flux around R2605 as well):
<PastedGraphic-1.tiff>
Maybe this (V5.2) Pick&Place coordinate list also helps: