PinePhone Pro Explorer's edition Qualcomm modem recovery

[zetabeta]

'Kay guys,

it seems i made it. Managed to get modem to work again (no connectivity though, need to install proper firmware anyway). The catch was to find the correct test points on my board to boot modem in to EDL mode, since they are unmarked and completely in different configuration than on the regular PinePhone. By analysing Quectel manual, board schematics and layout diagrams, i managed to find the correct test points to short. I must say, that this task is very inconvenient, because the test points are like 1mm in diameter and in opposite chip corners. Since i have tow-boot installed, i had to short these points with one hand while operate hardware buttons with other hand. The pins must be shorted all the way up until OS boots up completely. It was fun experience  I am adding image with marked spots where the points are located on PinePhone Pro explorer's edition motherboard (upper point is actually at the top right corner of the chip on my motherboard).

P.s. special thanks to @mikehenson  for independent validation and verification of the procedure, so i was able to be more confident to perform it succesfully.

P.p.s the points are in a slightly different location on my ppp. Top point is on the top/right corner of the modem rf shield, and available to reach.

Can you post back an image of higher resolution of the board?  I cannot read some of the labels.  I understand if you cannot but I hope that there is one.

i don't think you need (new) high-resolution pictures.
https://files.pine64.org/doc/PinePhonePr...bottom.pdf
https://wiki.pine64.org/wiki/PinePhone_P...ifications

labels seems to be:
up: T6503
down: T6504