I just set up my voltage on both sticks slightly above 1,5 V. Starting with 100 MHz until 200 MHz works fine.
At 225 MHz one works and one goes zombie after a short time.
At above 250 MHz I get this right after starting:
cgminer version 4.10.0 - Started: [2017-11-27 19:48:51.017]
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(5s):0.000 (1m):0.000 (5m):0.000 (15m):0.000 (avg):0.000h/s
A:0 R:0 HW:0 WU:0.0/m
Connected to connect.pool.bitcoin.com diff 4.1K with stratum as user derwasi
Block: 8d1340e3... Diff:1.35T Started: [19:48:50.068] Best share: 0
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[U]SB management [P]ool management [S]ettings [D]isplay options [Q]uit
0: GSD 10012603: COMPAC-2 250.00MHz HW:0 | ZOMBIE
1: GSD 10010286: COMPAC-2 250.00MHz HW:0 | ZOMBIE
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[2017-11-27 19:48:49.492] Started cgminer 4.10.0
[2017-11-27 19:48:49.494] Loaded configuration file /home/pi/.cgminer/cgminer.conf
[2017-11-27 19:48:50.017] Probing for an alive pool
[2017-11-27 19:48:50.067] Pool 0 difficulty changed to 4096
[2017-11-27 19:48:50.068] Network diff set to 1.35T
[2017-11-27 19:48:50.120] Found 2 chip(s) on GSD 0
[2017-11-27 19:48:50.122] Found 2 chip(s) on GSD 1
[2017-11-27 19:48:51.105] GSD 0 failure, disabling!
[2017-11-27 19:48:51.112] GSD 1 failure, disabling!
Is this a power issue? The voltage to set is the total string voltage, right?
I have a 30 W power supplied hub. That would be 6 A at 5 V. So three A per stick. The table on post#1 says 2.8 A at 1,5 V and 300 MHz. So it should be enough power, right?