Rasbee II: firmware flashing flashing not working, hardwar defect?

next try:

debug log of GCFFlasher


slip put 0xA6
slip put 0xAC
slip put 0xC0
09:30:37:357 TX c0818400007d02009e007cdc9f7ebb3d63780e92215ad3d71cbae1cbdbdd4d695c98449099d07f513e094826dcf9ace5459007a91c5c9997a1eee63f3fc6d2ba364c507b64084902b644e5990ba33fb4dbdd7a61ddd8a0e6820912f8adef00d1bfb43f353cae1760e2e7c6bf21bd39dbddd21de96be6c5e83139ba4d0d2d288efdf5f0a7902e720cb9b7f275da4e0cc3cc86c4a57453338a9ab65b8141a2dbddc3025f73d3a20100ffc5022ca6acc0
09:30:37:357 bootloader v3 finished all data
|09:30:38:308 verify application is running
09:30:38:309 query deCONZ firmware version
09:30:40:311 failed to query application
retry, failed

GCFFlasher_internal -l

GCFFlasher V3_17 (c) dresden elektronik ingenieurtechnik gmbh
Path | Vendor | Product | Serial | Type
-----------------±-------±--------±-----------±------
/dev/ttyAMA0 | 0x0000 | 0x0000 | | RaspBee

After rebooting, the gateway still reports:

Version: 2.19.03 / 19.9.2022
Firmware: nicht verbunden (not connected)