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How to open the back of a Compaq FP5315 LCD Monitor

By hogwillie
Oct 10, 2009
  1. Hi folks,
    I've looked over the posts and can find no previous post on this subject.
    I have a Compaq FP5315 LCD monitor. I can't get the back off. I've found the fours screws (two recessed above the base and two in the bottom corners) and what I think are pressure release clips inside slots in the bottom edge. I've peeled back the label on the center of the back and found what looks like a molding sprew or a glued in plastic plug.This doesn't seem to come out.
    Something is still holding this back on. Can any of you assist me?
    I've found a user manual and a repair manual. but neither has the dis-assembly instructions.
    I'd appreciate any guidance that any of you can provide.
    Thanks,
    Bill
     
  2. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Use a large flat-blade screwdriver, and press it firmly in the crack between the front and back plastic housings. Carefully release the plastic retainers. You might have to twist the screwdriver a bit, but be careful not to mar or crack the plastic too much
     
  3. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    Thank you for your reply.
    I found the two plastic clips inside the cracks in the bottom edge. I got them to release but something still seems to be holding the back in place.
    So far this is what I've found:
    Two screws in the bottom corners of the back.
    Two screws recessed on the back above the pedestal.
    Two plastic clips inside small rectangular openings in the bottom edge.
    Am I still missing something?
    Thanks again for your help.
    Bill
     
  4. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Does the VGA cable detach, or is it secured inside the monitor? It has been some time since I worked on these. What is the manufacturing date? 2004?

    What is the problem? No video, flashing intermittant video
     
  5. nismo91

    nismo91 TS Evangelist Posts: 899   +15

    i have a 2006 LG 15 inch LCD. at the sides of the screen, there are "pressure" clips. for my case, i accidentally opened the front "frame" because the LCD fell down.

    u might try to open the front frame first, maybe it helps.
     
  6. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    nismo91,
    Thank you for your suggestion. I followed the advise of an earlier reply from Tmagic650 and the case back popped right off. It seems that I was using to little force in my effort not to break something. I twisted a bit harder with a large flat screwdriver blade and the clips all around the edge released one at a time.
    On another point: do you have any idea where I might find an actual schematic for this monitor? I have a service manual with a block diagram and theory of operation, but it has no schematic or parts placement layout. I may be able to make do with what I have but a real schematic would be useful.
    Thanks again for your help.
    Bill
     
  7. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    Tmagic,
    Thanks again for your reply.
    I got the case open. I followed your instructions and it popped right open. It seems that, in my efforts not to break something, I had been using too little force when it tried before. A bit more torque on the screwdriver and the clips release one at a time as nicely as you please.
    OK, the problem with the monitor is this: when I push the power button to turn it on the green power light comes on for just a second then goes off. I never get any kind of display at all. I suspect that something is knocking down the power supply, but I haven't gotten far enough into the troubleshooting to determine this yet.
    I'm not sure what the date of manufacture is. I peeled the sticker off of the back looking for hidden screws. I'll have to smooth it out and try to determine the DOM.
    The video cable is integral.
    I now have the back open and the EMF shield removed. I've been looking at the power supply board but I don't see any obvious burns or damage.
    I've heard stories about capacitors that "bulge just a bit" indicating failure. I think I may see something like that, but none are obviously leaking.
    This appears to be a switching power supply, but I don't have a schematic to verify this. I do have a service manual with a block diagram. I haven't studied it in detail yet, but I'll do that today. Do you have any idea where I might get an actual schematic for this monitor?
    The service manual is published by Lite On. Would that be the OEM? Do you know how I might figure out who the OEM is?
    I'm rambling now. I'll close this note with thanks again for your help.
    Bill
     
  8. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    Tmagic,
    Thank you for your reply.
    I've looked at the label on the back. The monitor seems to have been manufactured in Aug of 2003. The documentation (dated 2003) is by LiteOn so I'm guessing they are the OEM.
    The problem is that when I turn on the monitor, the power led goes green for about one or two seconds, then goes out. No amber, no green. There is no display at all.
    The service manual starts it's troubleshooting procedure from either a green led or an amber led. The block diagram isn't sufficiently clear. I could really use a schematic with a parts layout diagram included. Do you know where I might get one?
    I'd appreciate any further insights that you might have on this issue.
    Thanks,
    Bill
     
  9. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    The one I worked on was a Compaq FP5317 (2004). From memory, it has 2 printed circuit boards. 1. Signal/chroma/video and 2. Power supply... It had intermittant video. I was able to aquire a complete non-working monitor from EBay for $14. I swapped video boards and my FP5317 was fixed. I never found any schematics
     
  10. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    Tmagic650,
    I've looked at this FP5315. Yes, it has two PC boards just like the one you worked on. I believe the power board is the problem. The data in the service manual that I got online doesn't seem to match the physical board. The component numbering is wrong. Still, I may be able to work my way through it.
    I'll start looking for a bad monitor or a power board from EBay or the net.
    Thanks again for your help.
    Bill
     
  11. hogwillie

    hogwillie TS Rookie Topic Starter Posts: 17

    I thank you for your help! I fixed it!
    The original problem was that when I pressed the power button to turn on the monitor I'd get a green led for about half a second or so, then it would go dark. No power.
    This is what I did.
    I opened the case and checked the fuse. It was good.
    I looked at the capacitors and noticed all five of the 470 uf, 16V, 105 C and both of the 1000 uf, 16 V, 105 C units were domed on the top. This is an indication of “Capacitor Plague.” “Capacitor Plague” is caused by the dielectric in the capacitor breaking down under excessive strain (voltage ripple/spiking and heat). This releases hydrogen from the dielectric which caused the capacitor to degrade. This eventually results in failure. I replaced all of the capacitors with 25 V, 105 C (the next higher voltage rating with the same temperature rating) caps.
    I also replaced the 7.5 V Zener Diode connected to pin 6 of the PWM. This is ZD904 on my monitor’s power supply PCB but may be different on yours. The tech data is very bad and the Tech manual part numbering doesn’t match the numbers on the PCB. Since this is a surface mount diode, and since I couldn’t find one like it at my local supplier, I used a 5 watt (massively over sized for the application) 7.5 V unit and it worked. It does require some care in the soldering of it in place. I did this because I read about it in another post. I just took the shot and it worked.
    In any event, having replaced the capacitors and that Zener Diode, the monitor is functioning again.
    I hope this helps some of you other folks. Good luck.
    Bill
     
  12. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Good work Bill,
    I'm glad I could help a bit...
     
  13. martinslater

    martinslater TS Rookie

    Hey folks,
    is new to this site, what an awesome resource. \
    Hardware: Monitor is a FP5315 (compaq) flat panel monitor..

    Symptoms: Monitor will switch on, indicator will go Green, Screen go a slightly pink color, display the screen, then the screen will blank out and the indicator will. switch to Orange.
    I am guessing it is a power supply issue of some description


    ISSUE: I got the black plastic backing off the monitor, I am not sure how to get the Metal shield off. there are three silver screws at the bottom. The left one holds a black cable going off a circuit board. Centre one just holds the metal down to the circuit board. the right one goes to another black cable going into the bottom circuit board. There are 2 screws on the left side and the right side . I am not sure to try and take the front panel off or undo the screws to the bottom and the side.
    .
     
  14. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    martinslater,
    I'm afraid that the symptom you describe is a common one with this Compaq model. It is caused by the video/ color IC not the power supply. You may have to replace the whole chroma board. It wouldn't hurt to check the circuit boards for heat damage or cold solder though. There should be 4 screws on the sides of the LCD display. They are hard to see and harder to get to. They are covered partially by the front plastic
     
  15. martinslater

    martinslater TS Rookie

    Tmagic650. With the pink/red tinting of the screen I was afraid of that. Oh I saw the 4 screws. silly me. Is there any way to test to see if it is the video/color IC?. I have looked around for a schematic but to no luck.
     
  16. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    There are no schematics available... With much lighter, higher resolution and bigger LCD monitors going for $150 or less these days, there is not much sense putting much time and money into repairing these heavy beasts. I was able to get a damaged Compaq FP5317 off EBay for $14including shipping. I used its parts to fix another FP5317. I charged the customer $85
     
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