Lamp DLP Cool Down ?

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Tech 57
    Member
    • Aug 2014
    • 37
    • United States
    #1

    Lamp DLP Cool Down ?

    Working on This Toshiba DLP 62HM95
    Burned up 3 Lamps Already about ready to throw the towel in.
    MY question is On the Cool down on this model.
    When you power this off should the lamp stay on.
    The lamp will not shut off it stays on for 2 min. then shuts off & fan shuts off at the same time.
    So the lamp is not being cooled down at All.
    Don't most dlps when you power it off the lamp should shut off right away so the fan can cool the lamp then the fan
    should stop after this cycle.
    Any Ideas!
    Tags: None
    • RCA2000
      Senior Member
      • Sep 2014
      • 111
      • USA
      #2
      Re: Lamp DLP Cool Down ?

      I WONDER...if perhaps you have a stuck power relay---for the ballast...that is NOT dropping out/stuck.. and leaving on the lamp till cool down period is over and ALL power is removed except for standby ? yes--that 2 minutes SHOULD be the cool-down period...and if it DID work that way...with a decent bulb like a Phillips...it should last awhile...

        Comment

        • japlytic
          Badcaps Legend
          • Oct 2005
          • 2086
          • Australia
          #3
          Re: Lamp DLP Cool Down ?

          Originally posted by RCA2000
          I WONDER...if perhaps you have a stuck power relay---for the ballast...that is NOT dropping out/stuck.. and leaving on the lamp till cool down period is over and ALL power is removed except for standby ? yes--that 2 minutes SHOULD be the cool-down period...and if it DID work that way...with a decent bulb like a Phillips...it should last awhile...
          Leaving the lamp on until cool-down period doesn't make much sense to me; normally, the lamp turns off before the fans remain running to cool down the lamp for a certain amount of time.
          My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

            Comment

            • RCA2000
              Senior Member
              • Sep 2014
              • 111
              • USA
              #4
              Re: Lamp DLP Cool Down ?

              I took a look at your diagram...what there is of it. It looks like the ballast is controlled by the light engine... Perhaps IT is not turing off the ballast soon enough...before the relay drops it out.

                Comment

                • budwich
                  Badcaps Legend
                  • Jul 2015
                  • 3097
                  • Canada
                  #5
                  Re: Lamp DLP Cool Down ?

                  perhaps you need to trace the powering path between the fan and the light engine. It sounds like the powering has "jumped" / "shorted" such that the light engine's powering is coming from the wrong point.

                    Comment

                    • eccerr0r
                      Solder Sloth
                      • Nov 2012
                      • 8662
                      • USA
                      #6
                      Re: Lamp DLP Cool Down ?

                      My Samsung DLP the lamp turns off about 10 seconds after you press power (the screen blacks out immediately when power button is depressed) and the fan remains turning for around a minute or so after the lamp actually turns off.
                      My BenQ DLP the lamp turns off when instructed and fan turns off around a minute afterwards.

                      Yes the lamp should shut off before the fan.

                        Comment

                        • R_J
                          Badcaps Legend
                          • Jun 2012
                          • 9514
                          • Canada
                          #7
                          Re: Lamp DLP Cool Down ?

                          I remember that certain Toshiba dlps did leave the lamp on during cool down, but check the menu for the " Quick Restart" feature on/off
                          I found this site http://www.hdtvmagazine.com/articles...g_your_hdt.php with this quote:
                          Toshiba engineering, on the other hand, claims this process is not necessary and that their products do not provide a cool down process; when the lamp turns off so does the fan.
                          On this forum the also mention this which would tell me thats normal operation for the Toshiba
                          http://www.avsforum.com/forum/63-rea...-s-dont-s.html

                            Comment

                            • RCA2000
                              Senior Member
                              • Sep 2014
                              • 111
                              • USA
                              #8
                              Re: Lamp DLP Cool Down ?

                              I FORGOT that ....DO check the menu and turn OFF ..that "quick restart" feature...it does keep the lamp on at least SOME...during cool--down...

                                Comment

                                • budwich
                                  Badcaps Legend
                                  • Jul 2015
                                  • 3097
                                  • Canada
                                  #9
                                  Re: Lamp DLP Cool Down ?

                                  Toshiba and others manufacturers in general all indicate the same thing about the "cool down" process. The main reason for fan cooling during shut down is to allow some form of "quick start" there after as the "heritage" of projectors was for presentations where people have been know to turn the projector on and off (standby) to reduce noise and other "distractions" during a presentation / meeting. The "bulb restart" process is extremely hard on the bulb especially if it is caused when it is still hot.

                                  Having said that, it is still reasonable to expect the bulb to go out before the fan turns off as the design intent so do the checks suggested (especially tracing the powering between the fan and bulb). Further, during your troubleshooting, do not restart your lamp until a "reasonable cool down" period to help prevent / reduce potential bulb issues.

                                  PS. what is the original problem that you were chasing, bulbs dying or something else?

                                  Further, 2 minutes seems rather long. My Optoma does a 10 second count down on "high speed" and then shuts down..... Hmmmm, does your fan ever operate at different speeds?.... may be a clue?
                                  Last edited by budwich; 02-28-2016, 01:10 PM.

                                    Comment

                                    Previous template Next

                                    Related Topics

                                    Collapse
                                    • vestaviascott
                                      Epson 5040UB Projector No Lamp Strike Stuck in Startup - Blinking Status/Lamp Lights
                                      by vestaviascott
                                      Hoping someone here can put me on the right track. I'm trying to troubleshoot/flowchart the "internal projector error" on my newly acquired Facebook Marketplace bought Epson 5040UB projector (3LED, not DLP). Owner said it needed new lamp, actually error code blink pattern indicates "Internal Projector Error, call Epson support". Unit is out of warranty as of 8/19

                                      Here's what happens:

                                      1) Power on
                                      2) Blue power indicator lights and the lens cover motor opens the lens cover, light fan noise heard
                                      3) Blue status light flashes for appx 4 minutes...
                                      07-29-2020, 06:08 AM
                                    • huzo
                                      HP Omen shuts down when loading OS
                                      by huzo
                                      The model is 15ec-1061nm
                                      Board number is DAG3EDMB8D0​

                                      SO i turn the laptop on , and as soon as it starts booting from disk, from usb, windows,linux,HBCD,anything i boot it just turns off....while in bios menu or in linux boot menu it stays on normally...It's like when it starts to use graphics it shuts down...But i measured 0.72V while working on the GPU power line,no excess heat is comming from GPU or CPU, i even removed the heatsink and turned the laptop on and everything worked fine, got a bit hot, fan span to full speed, but it worked like that for few minutes in bios...
                                      10-29-2024, 12:05 AM
                                    • mikey5791
                                      Help on Samsung Syncmaster T220 dead ccfl lamp
                                      by mikey5791
                                      Hi,

                                      This monitor previously is my main working monitor which i have been using for 8~9 years. Yesterday, when i switched on my pc from fresh to power on, the monitor is just black no display. I started dismantle to look inside the monitor power board but nothing looks suspicious or burnt. So i took my external ccfl inverter to try to power the monitor ccfl lamps which consisted of 2 lamps on upper part and 2 lamps on the lower part.

                                      Found out the upper ccfl lamp which is supposed to connect to cn304 on the power board did not light up. Then i installed a used working...
                                      10-18-2020, 03:17 AM
                                    • khelane
                                      test active pfc power with lamp test
                                      by khelane
                                      Hello
                                      I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
                                      Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
                                      Is there a way...
                                      06-03-2025, 01:00 AM
                                    • chaos-theory
                                      Asrock z97x starts then shuts off after 4 seconds, sometimes more, no post
                                      by chaos-theory
                                      I have a really weird problem, this motherboard was working normally, someday it just started and all fans were running but didn't want to post, tried resetting bios, checking CPU and it was getting warm tried external gpu, flashed bios with programmer, but same problem.
                                      Next day after several attempts the board goes into protection mode, no more staying on, I turn on the PSU fans starts directly turning, it used to not start until I press the pwr button, now it starts directly and fans spins, and shuts off after 3 seconds sometimes less, then won't start again unless I unplug the PSU and...
                                      03-14-2025, 05:37 PM
                                    • Loading...
                                    • No more items.
                                    Working...