q: 
How to service db2010/db2020/pnx5230 cid52/cid53 using new setool2 (>=v0.914029) alternative bypass method ? 
what problems i can meet and how to resolved them ?
what precautions i should follow ?

a:

terms:
phone should work fine.
red blink, white blink, etc phones are NOT supported.

you can only use alternative bypass if your phone has supported firmware (you have BOTH rest file and bypass package)
if yours firmware not supported, either flash supported firmware (only main part in enough) or post request on forum.

BEFORE using new alternative bypass method you SHOULD turn phone on and install CSCA(MODEM) drivers.

i STRONGLY recommending to browse that FAQ and READ article about com-ports growth - there is EXTREMLY helpful file,which
prevents discovering of same phone models as new devices. 

if you are capable user, you can edit .inf files of CSCA(MODEM) drivers - we only need to install
Sony Ericsson Device XXX bus driver and Sony Ericsson Device xxx USB WMC Modem - all other devices is not needed.
that will help you to save comport numbers.

important! if your phone had unsupported firmware and you flashed main part (all parts) of supported - you MUST power on phone, so phone will update new firmware info.

because of way new alternative bypass method works, you need
TEST SIM card (mcc/mnc 00101) or OPERATOR SIM card. (you must be able browse phone menu,etc)

.....will be updated soon.......

supported following models:

db2012 cid52 - normal CID52 phones (w200,w300), abnormal CID52 phones (k310,k510,w810,z550)
db2020 cid52/cid53 phones
pnx5230 cid52/cid53 phones

supported operations:
unlock via patch, all additional things that setool2 can provide.

Procedure of new alternative security bypass :

1. select correct phone model
2. go to settings tab, 
3. check BOTH "signed mode (using server)", "enable alternative security bypass", that is required
4. optionally, check "unlock after flash", "patch otp<>gdfs check in firmware"+"allow to change IMEI when unlocking" (read precautions)
5. optionally, check "complete phone after flash" (i recommend use custpacks)
6. go back to semc tab
7. if you need, add main+fsimage+custpack (script)
8. press desired operation
9. when asked, disconnect phone, insert TEST SIM, power on phone fully and connect it.
10. when asked, disconnect phone, remove battery, insert battery and connect phone while holding corresponding button ('C' or '2' for w880)

approximate time for unlock by patch using new alternative bypass method is 160-180 seconds on one phone.

.....will be updated soon.......

precautions:
please take care that there is NO (at least, i can't get) cid52 firmwares for following db2010 phones: k310,k510,w810,z550

luckily, k310,k510 can be flashed with w200 firmware, so we can always return them to original state.

but it is NOT related to w810,z550 phones.
cause there is no firmwares, we can't recover them in case of error.

because of that, one mistake with that phones - and you get deadweight.
you have been warned.

under mistake i mean: 
- terminated flash or anything,which prevents phone from starting up
- changed IMEI of phone, which prevents phone from using new alternative bypass method.

.....will be updated soon.......

possible problems:

in case of terminated flash/etc you can always return phone to life by flashing any original firmwares into them - 
and then it ready for execution again 

db2012 k310 (via w200),k510 (via w200) ,w200,w300 - supported cid52 firmwares available.
db2020 supported cid52/cid53 firmwares available
pnx5230 supported cid52/cid53 firmwares available

.....will be updated soon.......

following firmwares are supported:
.....will be updated soon.......