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orlandolaconcha · 11-04-2011, 22:40

hello friend who tells me what is jtag PS_HOLD in ort

rajeshchiyyan · 11-05-2011, 05:25

What is PS_HOLD ?

The idea is If you can’t keep phone powered on PS_HOLD will do it for you
PS_HOLD is a Test Point that designed to keep cpu powered up while supplying a battery power .

Some Power Management IC’s are not able to hold dead handsets powered up and it affects operating while JTAGGing them that’s why they have PS_HOLD Points

It is required to make PS_HOLD Connection if it is exist on the pcb just to make sure everything will be stable while you are repairing the phone

There is another way to keep the phone up is : Keep pressing the power button !

How to use :

Dead Qualcomm handsets sometimes require PS_HOLD Connection on the board and purpose of this powering up the phone’s cpu by force

Basic connection is connecting PS_HOLD to VBAT with a resistor .

What is the Value of resistor that you should use :

Since VBAT Source differs on different phones which average is 3.6V to 4.2V
we should use something between 1K and 4.7K

11-04-2011, 22:40	#1 (permalink)
orlandolaconcha Freak Poster Join Date: Sep 2009 Location: MOVIL GSM / VENEZUELA Posts: 228 Member: 1123972 Status: Offline Thanks Meter: 28	hello hello friend who tells me what is jtag PS_HOLD in ort

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11-05-2011, 05:25	#2 (permalink)
rajeshchiyyan Product Supporter Join Date: Jul 2010 Location: MobilesFactory,trichy,TN,India Age: 33 Posts: 1,523 Member: 1347585 Status: Offline Sonork: 100.1596390 Thanks Meter: 467	What is PS_HOLD ? The idea is If you can’t keep phone powered on PS_HOLD will do it for you PS_HOLD is a Test Point that designed to keep cpu powered up while supplying a battery power . Some Power Management IC’s are not able to hold dead handsets powered up and it affects operating while JTAGGing them that’s why they have PS_HOLD Points It is required to make PS_HOLD Connection if it is exist on the pcb just to make sure everything will be stable while you are repairing the phone There is another way to keep the phone up is : Keep pressing the power button ! How to use : Dead Qualcomm handsets sometimes require PS_HOLD Connection on the board and purpose of this powering up the phone’s cpu by force Basic connection is connecting PS_HOLD to VBAT with a resistor . What is the Value of resistor that you should use : Since VBAT Source differs on different phones which average is 3.6V to 4.2V we should use something between 1K and 4.7K