GSM-Forum - View Single Post - iPhone 4 NO VOLTAGE @ R500_RF BASEBAND WON'T START

loser18 · 02-13-2014, 08:52

Hi every one...

The story:

Got an iphone 4 from joblot of other phones, so don't know the history...
Didn't look like water damaged...
The phone came with bb CPU missing,so I've replaced BB CPU & BB FLASH...
Phone turns on but have NO wifi,bluetooth,baseband,iccid or IMEI...
I've had L2_RF=1.3v & L3_RF=1.8v and no voltage at R500_RF...
I've reballed & also tried another U11_RF...
After that reballed U8_RF with no luck but the L2 voltage changed after reball to L2=1.6V & L3 is still 1.8V...

C4_RF
C18_RF
C46_RF
C26_RF

These 4 caps voltages are ok???

Anything else i should check???

THX FOR ANY HELP IN ADVANCE>>>>

FORGOT TO TELL THAT U11_RF IS GETTING VOLTAGE AS FL3_RF READS 3.7V on booth sides & C67_RF getting 0V???

02-13-2014, 08:52	#1 (permalink)
loser18 Junior Member Join Date: Mar 2012 Location: UK Posts: 29 Member: 1739597 Status: Offline Thanks Meter: 0	iPhone 4 NO VOLTAGE @ R500_RF BASEBAND WON'T START Hi every one... The story: Got an iphone 4 from joblot of other phones, so don't know the history... Didn't look like water damaged... The phone came with bb CPU missing,so I've replaced BB CPU & BB FLASH... Phone turns on but have NO wifi,bluetooth,baseband,iccid or IMEI... I've had L2_RF=1.3v & L3_RF=1.8v and no voltage at R500_RF... I've reballed & also tried another U11_RF... After that reballed U8_RF with no luck but the L2 voltage changed after reball to L2=1.6V & L3 is still 1.8V... C4_RF C18_RF C46_RF C26_RF These 4 caps voltages are ok??? Anything else i should check??? THX FOR ANY HELP IN ADVANCE>>>> FORGOT TO TELL THAT U11_RF IS GETTING VOLTAGE AS FL3_RF READS 3.7V on booth sides & C67_RF getting 0V??? Last edited by loser18; 02-13-2014 at 08:58.