Star / Alps S9920 Screen Repair

Is Your Phone Acting Up?

s9920A week ago I wrote a review of the Alps / Star S9920, in which I highlighted some of the highs and lows of buying this popular S3 mini clone. Shortly after after writing the article I began receiving messages from fellow S9920 owners, who were also struggling with their devices. While I still don’t have a solution to all the problems that have been put to me (and I did look) there just isn’t that much documented on the S9920. This isn’t much of a surprise, when you think of the number of phones that come out of China. Unlike major brands such as Samsung, HTC or Apple, Alps constitute but a footnote in the Android device market.

In this article, I’ll try to address one of the main issues experienced by users of the S9920: ghost touching. It manifests itself in the form of icons randomly selecting themselves without the screen ever being touched. This fix may also help with some of the other problems associated with the digitizer / screen on the S9920.

Before we begin, I must stress that this is a very tricky fix and requires you have a steady hand for soldering. I would only recommend you attempt this fix after exhausting all other avenues. Make a mistake and you could very well damage your phone beyond repair. Know that you do this at your own risk, and I cannot be held responsible if you kill your phone. With the disclaimer out of the way, let us continue.

The Phone Blues

A month after receiving my phone, the tell tale signs that something wasn’t quite right, began to emerge. Sometimes I would pick up my phone and the screen would not register my finger swiping the screen, while on other occasions the phone would act as if it had been possessed, randomly opening apps, usually located at the bottom right of the screen, close to the back button. The only way I found to make it stop, was to place the phone on a flat surface and run a finger firmly across the screen, directly over where the back button icon is located.
A few minutes doing this and the phone usually would begin to act normally. However these bouts of the ‘crazies’ were becoming ever more frequent, making the phone very unreliable for daily use. After contacting Dracotek, the company I bought the phone from. I explained the problem I was having with the phone and their representative kindly offered to replace the faulty handset. This really is a Chinese company with good customer support, in fact the best I have encountered. Generous as the offer was, after reading all the articles I could about the S9920, I realised that a replacement would only delay the inevitable, as the S9920 clearly has an inherent flaw in regard to the touch screen. After making sure I had a back up phone, I decided to try out a suggestion I found online while reading up on the S9920. This involved carefully disassembling the phone, detaching the screen and removing the motherboard. Then, with a fine tip soldering iron, reflowing several points on the rear of the board. Without any photos to go on, this possible repair was really a shot in the dark, but I decided I to give it a go.

Things you will need:

To perform this fix you will require:

1x 25watt soldering iron

1x Set of Phillips screwdrivers

1x Small flat screw driver or plastic separating tool, as used in opening iPods

Disassembling your S9920

First make sure your phone is turned off, then remove the back cover and the battery, place them to one side. Next using a small Phillips screwdriver, remove the eight screws from the rear of the phone. The bottom right screw is covered with a white sticker. By breaking this you will void the warranty of your device, which means you won’t be able to return your phone, so be certain that you wish to continue.

With the screws removed, pick up the phone and examine the edge. You should see a series of small slots, this is where you will need your small flat headed screwdriver. Start by inserting it into these slots and gently prying the plastic apart.s9920-screwdriver3 The back and front of the phone should gradually come apart. With the back removed, carefully unclip the two connectors indicated in the photo. s9920-connectorsThese are for LCD screen and front facing camera. Before you go lifting out the motherboard, you will need to un-stick the power and volume buttons. First remove the plastic buttons that cover them. Underneath these are the switches, held in place with sticky back tape. Using a flat blade screwdriver, pry them away from the case. Remember be careful, replacement parts for the S9920 are scarce on the ground. Once you have them unstuck, lift the board up and away from the front case. You should now have the three parts of the phone laid out in front of you. s9920-threeparts copyThe black rear shell, logic board and front case, which includes the LCD screen (See picture). Don’t lose the plastic home button, located at the bottom of the front case. Turn the logic board over so it looks like it does in the picture above. Now gently remove the yellow tape covering the solder points. There should be one large square at the top of the board and a smaller one at the bottom for the hardware button.

A steady hand will be needed for the next part. Using a fine tipped soldering iron, heat up the contacts you uncovered from under the tape and ONLY those. Don’t spend too long with the iron on the board, you only need to warm up the solder enough for it to reflow. You should be able to see it happen. The solder will visibly change in appearance, becoming shiny. s9920-contacts copyThe contacts pictured above are very fine and tricky, take your time and try not to rush. Once you have done these, finish off by reflowing the contacts you uncovered on the bottom half of the board.

*Additional note: After I reflowed all the contacts, I took a Stanley knife and scored the board between the tracks, just to eliminate the chances of bridges between the lines. You can do this as well if you wish, simply use a sharp blade and run it down between the contacts your have reflowed. Make sure you do not score the brown ribbon cable, it is fragile and will not react well to sharp blades.

Before you reassemble the phone, take a look at the board containing the hardware buttons (see picture). On my S9920 this narrow board was not sitting level, which meant it was not aligned well with the front case. s9920-hwbuttonsThis could easily have attributed to the problems I was having with the back button. The board is stuck down with double sided tape, but can be lifted off by sliding a something under it. Apply a little pressure with a flat bladed screw driver or Stanley knife, be careful as the board does flex and you do not want to snap it. Once it is unstuck, carefully reposition it and press it down, the tape will keep it in place. You can see how mine was slanted in the photo.

Well done! You have done the fix and hopefully your phone should behave a little better. Now you can carefully begin reassembling your phone. You can do this simply by reversing the process of taking it apart. Remember to be careful of the screen and camera cables as well as the volume and power buttons. Remember to place the home button back in the front case before you replace the motherboard.

Update 

So it has now been five days since I took my S9920 apart in a last ditched effort to get the phone performing properly, specifically the screen. I’m happy to report the repair seems to have worked! So if your screen is acting up as described above, this fix might and I must emphasis might! Restore your phone to normality. I was dubious as to whether reflowing the contacts have any effect, but it has. I can only conclude the traces on the board are simply not very good or perhaps scoring the board as I did, isolated the tracks and stopped any bridging that might have been occuring.

That’s all for now folks, keep on geeking!

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15 Comments on “Star / Alps S9920 Screen Repair”

  1. titicom says:

    Hello and congratulations for your articles on the s9920 ….
    finally someone who is interested in this smarphone ….
    I would also like to have a tutorial on changing the window of the phone?
    can you do that?
    thank you in advance

  2. Hugo says:

    Thanks.
    I’ve followed instructions and is working.

  3. Gabor says:

    Hello,

    I would like to know if the repair is still working? I am decided to do the same on my S9920, but I wanted to check if the fix is ok before opening the phone.

    Regards,

    Gabor

    • heamogoblin says:

      Hi there, the repair turned out to be temporary. This appears to be a design fault with the phone.

    • heamogoblin says:

      Hi there, the repair did not last. I am now convinced that these phones have a design fault. I’m also willing to bet it is linked with the charging port and the fact the screen is not glass, but plastic. The constant flexing of the USB port, seems to stress the lower half of the screen, causing the ghosting.

  4. avishai says:

    Hi I have s9920 that I sent to china and they replace the screen ,now it has a problem with the proximity sensor and when there is a call the screen turn off and the phone loacked, I did every thing I opened it and checked thatbthe sensors not blocked, I replace the rom, I tried to blocked it with sensor app and didn’t succseed , I checked it with app that check this and it said that the proximity sensor is near (0). Do you know what can I do? maybe i can cancel the sensors phyiscally? Thanks

    • heamogoblin says:

      I’m not entirely sure what is wrong with your phone, are you saying the phone locks during a call and does not detect the proximity of your head when your speaking?

      I’m afraid I am not a phone expert. I have received a number of messages asking about this handset and I’m sorry to say I can not offer much help. My only advice would be to ask for a refund or try to get your phone exchanged again for a working model.

  5. avishai says:

    O.K. Thanks.

    • heamogoblin says:

      My pleasure, I’m only sorry I was not able to offer you any help. After discovering the problems with my own Alps phone, I realised I had to take a loss and buy another phone. Really in the long run, buying from a main brand is the safest option and will avoid most of the problems faced with the S9920.

  6. Thomas says:

    Hello from Austria,
    my S9920 Excelvan had the described problems with homebutton and the screen, After resoldering the cables it is working like a charm. THANK YOU VERY MUCH FOR THIS DECRIPTION ! Bye, Thomas

  7. bigkoelho says:

    Hi, i have a alps 9920, and works very fine. I´ve broken the front glass (but stil work perfect). do you know where i can buy the screen?

  8. […] previously described on ByteMyVdu, now might be as good a time as any to check out the following link and familiarise yourself with it. Needless to say the fix outlined in the aforementioned article […]

  9. […] AW: Star S9920 MTK6577 Dual-Core Dual-SIM Android 4.1 Star / Alps S9920 Screen Repair | Byte-My-Vdu […]


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