Announcement

Collapse
No announcement yet.

Acer 1716 problems

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
    #1

    Acer 1716 problems

    Ok, guys, I've been reading around on the forums, and decided to ask you guys what I should do.

    I have recently taken up a hobby of fixing LCD monitors with Capacitor problems. Been buying them cheap and reselling them. I have been pretty successful so far.

    But, I have run into an inverter that won't be fixed by replacing the caps.

    The issue is that when "cold" the monitor will display for about 1 minute, then the back light cuts off. Then, if you turn it off and back on, it displays the Acer logo, then cuts off, then flashes the backlights 1 more time, then nothing.

    This inverter has 3 - 25V 470 μf, 2 10v 1000μf, 1 - 10v 470μf, and 1 - 50v 22μf. I replaced them all with the exact voltage and μf rate Rubycon and Samxon caps that I got from Badcaps.

    I resoldered the tranformer pins and also replaced the large 470v cap with a known good one. still no dice.


    Any suggestions would be helpful. I have a multimeter and have also check the resistance on the fuse. It appears to be good to go.

    What should I try next?

    Last edited by Skoffer; 06-12-2011, 11:32 AM.
    Tags: None
    #2
    Re: Acer 1716 problems

    Here's what I would.
    Verify the backlight on voltage stays the same when the lamps shut off.
    Identify the inverter secondary coils and see if they are within 3%of each other.
    Substitute known good CCFLs.
    Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

    Comment

      #3
      Re: Acer 1716 problems

      Originally posted by alexanna View Post
      Here's what I would.
      Verify the backlight on voltage stays the same when the lamps shut off.
      Identify the inverter secondary coils and see if they are within 3%of each other.
      Substitute known good CCFLs.
      The CCFLs good. The panel has been tested with a good inverter. no issues.

      Comment

        #4
        Re: Acer 1716 problems

        Peel back the glue and check the resistance between the 2 pins circled red
        and do the same to the 2 pins circled yellow and post results
        Attached Files

        Comment

          #5
          Re: Acer 1716 problems

          multimeter is showing infinite resistance across both. What exactly is that component?

          Comment

            #6
            Re: Acer 1716 problems

            Originally posted by Skoffer View Post
            multimeter is showing infinite resistance across both. What exactly is that component?
            Dependant on the Board that is fitted. resistance MAYBE approx 856 ohms for both coils !!! what resistance scale was your meter set to ??

            Comment

              #7
              Re: Acer 1716 problems

              Originally posted by Rtech View Post
              Dependant on the Board that is fitted. resistance MAYBE approx 856 ohms for both coils !!! what resistance scale was your meter set to ??
              I had it on the lowest setting. I didn't realize it could be so much, I will retest on a higher setting.

              EDIT -
              Ok, It is showing 1013 across the red
              and 1010 across the yello.
              Last edited by Skoffer; 06-12-2011, 12:32 PM.

              Comment

                #8
                Re: Acer 1716 problems

                Alexanna asked you to check B/Light voltage ??
                With everything plugged in,including a PC input,check the Voltage on the On/Off pin,should be between 3 and 5 volts DC as long as the Logic board has a signal from the PC and has recognised it.

                Comment

                  #9
                  Re: Acer 1716 problems

                  Originally posted by Skoffer View Post
                  Ok, It is showing 1013 across the red
                  and 1010 across the yello.
                  Those are the secondary inverter transformer pins. Your readings suggest they are good.

                  PS. We prefer pictures uploaded here using the manage attachments functions and not inline.
                  --- begin sig file ---

                  If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

                  We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                  Please do not post inline and offsite as they slow down the loading of pages.

                  --- end sig file ---

                  Comment

                    #10
                    Re: Acer 1716 problems

                    Originally posted by Rtech View Post
                    Alexanna asked you to check B/Light voltage ??
                    With everything plugged in,including a PC input,check the Voltage on the On/Off pin,should be between 3 and 5 volts DC as long as the Logic board has a signal from the PC and has recognised it.
                    I don't really know what you are talking about. Any chance you can explain in more detail? Where are the On/Off pins?

                    I'm not very experienced using a multimeter. Which setting should I have it on? Where do I put the black wire, where do I put the red?

                    Comment

                      #11
                      Re: Acer 1716 problems

                      Originally posted by retiredcaps View Post
                      Those are the secondary inverter transformer pins. Your readings suggest they are good.

                      PS. We prefer pictures uploaded here using the manage attachments functions and not inline.
                      Sorry about that. I'll remember next time. It won't let me edit my original post, or I would change it, now.

                      Comment

                        #12
                        Re: Acer 1716 problems

                        On the very short side of the Board, there are 8 pins which plug into the Logic Board, they will be labelled on the boards, and you need to put the black probe on Ground and the Red on the On/Off pin and measure DC volts.take your time as obviously there will be Power On, so be very careful.Also Have you got any Spare Loose Backlights, Or another 17 " Screen that is working ??

                        Comment

                          #13
                          Re: Acer 1716 problems

                          Originally posted by Rtech View Post
                          On the very short side of the Board, there are 8 pins which plug into the Logic Board, they will be labelled on the boards, and you need to put the black probe on Ground and the Red on the On/Off pin and measure DC volts.take your time as obviously there will be Power On, so be very careful.Also Have you got any Spare Loose Backlights, Or another 17 " Screen that is working ??
                          I don't have any loose backlights, but I do have a few cracked panels I could probably pull the backlights out of. I DO have another 17" screen that works, but the panel that I am currently testing this inverter with came out of a perfectly fine working monitor. I know that the backlights in this panel work.

                          I am getting 3.26V on the On/Off pin.

                          Comment

                            #14
                            Re: Acer 1716 problems

                            In that case, if you are TOTALLY satisfied the B/Lights are good, then the chances are the problem is one of the Mosfets.To take you through that tonight,I'm afraid I cannot do.You need to Get the Part codes off them, and then the data sheets.

                            Comment

                              #15
                              Re: Acer 1716 problems

                              Originally posted by Skoffer View Post
                              I don't have any loose backlights, but I do have a few cracked panels I could probably pull the backlights out of. I DO have another 17" screen that works, but the panel that I am currently testing this inverter with came out of a perfectly fine working monitor. I know that the backlights in this panel work.

                              I am getting 3.26V on the On/Off pin.
                              If you have good CCFLs that are in broken panel, I would suggest removing them. In future repairs they come in handy because you are able to see if each inverter coil has the ability to light the CCFLs, and if they are of equal brightness.
                              I want to clarify, Dose the on/off pin stay the same voltage when the lamps shut off?
                              Last edited by alexanna; 06-12-2011, 02:39 PM. Reason: edit
                              Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                              Comment

                                #16
                                Re: Acer 1716 problems

                                Since the monitor seems to work fine for the first minute and then shuts down, it might be a possible indication of a bad solder joint and/or a component that is overheating. Try cooling the power board with a fan to see if you can get it to remain on for a longer period.

                                Comment

                                  #17
                                  Re: Acer 1716 problems

                                  Originally posted by alexanna View Post
                                  If you have good CCFLs that are in broken panel, I would suggest removing them. In future repairs they come in handy because you are able to see if each inverter coil has the ability to light the CCFLs, and if they are of equal brightness.
                                  I want to clarify, Dose the on/off pin stay the same voltage when the lamps shut off?
                                  Yes, the voltage stays the same. It didn't fluxuate at all.

                                  Comment

                                    #18
                                    Re: Acer 1716 problems

                                    Try with CCFLs that are not inside a panel.See if you notice anything different between the bulbs
                                    Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                                    Comment

                                      #19
                                      Re: Acer 1716 problems

                                      Ok, I pulled the CCFLs out of a cracked panel that I have. That monitor worked fine other than the cracked screen, so I am aobut 99.999% confident that these CCFLs are working properly.

                                      Anyway, I plugged them in to the monitor and got the same response. When I turn the panel on, they light up, then go off, then flash 1 more time, then nothing.


                                      I have another inverter that I am having a similar problem with, I may post pictures of it later, but it is also off of an Acer LCD and is nearly identical to the one in this thread, except it only has 7 pins instead of 8 pins to the logic board. Anyway, if we can figure out the problem on this one, I'm hoping it will also solve the problem on the other.

                                      Any advice on how to test the mosfets would be much appreciated. But, looking at this board, I'm not sure if I would have the soldering skills to replace them. I've gotten pretty handy with soldering caps, but the mosfets are tiny.

                                      Comment

                                        #20
                                        Re: Acer 1716 problems

                                        Originally posted by jetadm123 View Post
                                        Since the monitor seems to work fine for the first minute and then shuts down, it might be a possible indication of a bad solder joint and/or a component that is overheating. Try cooling the power board with a fan to see if you can get it to remain on for a longer period.
                                        Actually, I can't get the backlights to stay on for any longer than a few seconds, now. The only time it lasted for a minute or 2 was right after I had replaced one of the caps. But, before you tell me to replace the caps again, I have already done this and it didn't solve the problem. To be clear, I have replaced the caps on this board twice, and the second time didn't change the behavior at all. Even if I leave it for a few hours, now, it still just blinks twice and then nothing. btw, the LCD is displaying the image, I can see the desktop when I shine a flashlight on it.
                                        Last edited by Skoffer; 06-13-2011, 10:25 AM.

                                        Comment

                                        Previous 1 2 template Next
                                        Working...
                                        X