[1amigo]

Originally Posted by lfc_fan

1amigo,

Will you be teaching us on water / liquid damaged phones, how to identify when a phone has been imersed in liquid, what the common faults are and how to repair them with step by step instructions using circuit tracing and diagrams. I have come across a few water damaged phones and common faults seem to be unresposive keypad and no backlight on LCD.

Thank you

Kind regards.

As you are having quite a number of water damaged phones, i assume that you are into Mobile Repairing in a Serious Way, CONGRATS ! I suggest you to equip yourself with the following 3 gadgets soon :
(1) Ultrasonic Cleaner and good quality Detergent Liquid to be used inside the UltraSonic Cleaner.
(2) A good quality and powerful Hand ****er to **** normal air but with much force over and around the PCB cleaned in the UltraSonic Cleaner. I would suggest the one used by Air-conditioner Mechanics, which is much heavier and powerfull also. This may sound funny or surprising but we are making use of it since long.
(3) A good quality of Hot Air ****er, not the Hot Air gun which we use for Soldering and desoldering. Here you may even use a good quality hair drier initially to avoid big investment.
I can suggest the exact make and model number of the ones which we are using.

The Procedure is fairly simple :
(1) Take out the PCB (without the LCD which is a glass part with Liquid inside and also without the inner kaypad ) and immerse it in the Detergent poured into the UltraSonic Cleaner (UC) and switch on the UC. The UC should switch off in 2-3 minutes time either automatically or manually. Though normally you won't need to but if necessary, again repeat the same procedure once more. (We normally use the same Detergent to wash around 4-5 PCBS before changing the detergent again.)

(2) Clean the PCB after taking it out of the UC by a simple tooth-brush kind of Brush and some detergent from another container containing fresh clean detergent, to Brush away any residues.

(3) Use the Hand ****er (Normal,not Hot Air kind) to remove all the residues and the liquids from the PCB for about 45-60 seconds by very slowly moving the PCB against the Powerfull Air Flow keeping it very near to the outlet of the ****er, so that all remanants like dried out salts which have been seperated from the PCB are removed completely from the PCB by the strong force of the air ****ing and any traces of water or the detergent etc. are also ****n off., in particular from the places between the PCB and the Chips and are not left there to cause damage in the future. This salts can very easily eat away the metals like PCB track or Balls and pins of the chips on the PCB and can make the PCB irrepairable at any time in the future. Therfore, it is necessary to remove all traces of the salts which have cripped in alongwith water or liquid.
(4) Next, **** the Hot air from the hot air ****er (Not the Hot Air Gun) over each and every portion of the PCB to ensure that all water or liquid is evaporated . The heat from the Hot Air ****er is not enough or likely to melt the solderings on the PCB and so the exposure to it for a few minutes is not likely to loosen any of the parts on the PCB whereas the Heat from the Hot Air Gun can be damaging if used for more time because it will melt the solder and you may **** off some components from the PCB if not done carefully ! (At this stage you will have in your hand a PCB looking as fresh as a brand new untouched PCB)

(5) Clean the Inner Keypad and LCD contacts with a small piece of cloth after applying IPA (Iso Propyl Alcohol) to the cloth and rubbing it gently on the contacts.

You may now reassemble the phone , insert the battery and try to switch on the phone. If you (and the Customer , of course) are lucky the phone will start working at this stage only and no more work required to be done on it. The success ratio till this stage is very easily near to 75 % of the cases and this way you can very easily recover the investment you made in buying the new tools as asked above !

However, if the phone does not switch on now, remove the PCB again and

(5) Finally, use the Hot Air Gun to resolder or reflow the chips normally. Never never press the chips down on board forcibly while reheating please . You may even need to reflash the phone software by using Griffin or UFS or Twister Box.


As per my experience more than 75 % of the water / liquid damaged phones start working by repairing in this manner. Rest 20-25 % may be more damadged because of the effort of putting the Battery and trying to switch it ON without completely drying out the Whole PCb and The Parts and so would need real fault finding to be done to diagonise the exact faulty components and replace them.

Hope this helps. Best of Luck ! All sincere effort without Luck is Futile ! No one can deny that sincere and hard work does help most of the times, though !