Dell E153FPB Back Light problem

[PlainBill]

Re: Dell E153FPB Back Light problem

Yes they all were. Its a cheap meter so i thought they were find.

I also looked at my LCD with a flashlight to see if i can see the image after it flashes white and i cant see an image. What does this mean?

It means something isn't working; probably either the logic card or the panel.

Take a good quality picture of both the top and bottom of the power supply / inverter. Don't use someone else's picture this time. There are at least two different versions of this monitor. Attach it to your next post.

PlainBill

[jschiefer]

Re: Dell E153FPB Back Light problem

Thank you PlainBill, I will upload pictures tomorrow. In the mean time I tested the transistors again and I'm getting continuity between the collector and emitter, which means they are bad right?

[PlainBill]

Re: Dell E153FPB Back Light problem

Thank you PlainBill, I will upload pictures tomorrow. In the mean time I tested the transistors again and I'm getting continuity between the collector and emitter, which means they are bad right?

Define 'continuity'. If you mean 10 ohms or less, you are exactly right. This is a fairly common problem with these boards. Here's what you do:

Check for C-E shorts on all four transistors (circled in red). If only one of a pair is shorted, replace both. Check the FETs for shorts (circled in blue). Replace if shorted, natch. IMPORTANT: Resolder all terminals on the transformers, even if they look good.

The parts can be found on eBay. You can buy kits of all parts, or if all you need are just the transistors you can buy them.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

The Dell E173FPB I repiared is at it again. When I plug it in I see the Dell Logo for just a split second and it goes dark. Using a flashlight I can see the Dell Logo is still there, just not lit up. I have replaced the Pico Fuse and all 4 of the C5707's and it worked for a few weeks. Now its back to doing the same thing. I have resoldered every connection that even looked funny. I paid particular attention to the spots reccomended on the forums. Any other idea's or things I can test? Thanking you in advance.
Pictures are attached

[Bobdee]

Re: Dell E153FPB Back Light problem

The Dell E173FPB I repiared is at it again. When I plug it in I see the Dell Logo for just a split second and it goes dark. Using a flashlight I can see the Dell Logo is still there, just not lit up. I have replaced the Pico Fuse and all 4 of the C5707's and it worked for a few weeks. Now its back to doing the same thing. I have resoldered every connection that even looked funny. I paid particular attention to the spots reccomended on the forums. Any other idea's or things I can test? Thanking you in advance.
Pictures are attached

If you resoldered all 4 Inverter Transformers then it is possible that you have a failing CCFL
Its is probable that you now have a failed C5707 again due to the initial fault being missed

[freakytiki4u]

Re: Dell E153FPB Back Light problem

You are correct. I just pulled the C5707's out and checked them with my MM and 1 was bad again. I replaced all 4 just to be sure but now 1 of the legs on one of the C5707's refuses to take any solder. I cleaned the area and am using rosen core solder but it will not take solder. I think that spot has just be soldered too many times. Im going to scrap this monitor also. Thank you for your assistance Sir

[Bobdee]

Re: Dell E153FPB Back Light problem

The Flat Panel I fixed has stopped working again. Now it just blinks on and off. Any ideas anyone? I was so excited to have it working.

Hello freakytiki4u
What did you mean in the above old post, did LED blink on/off or the screens B/Lights

[freakytiki4u]

Re: Dell E153FPB Back Light problem

The Power LED Just blinked repeatedly.

[Bobdee]

Re: Dell E153FPB Back Light problem

You are correct. I just pulled the C5707's out and checked them with my MM and 1 was bad again. I replaced all 4 just to be sure but now 1 of the legs on one of the C5707's refuses to take any solder. I cleaned the area and am using rosen core solder but it will not take solder. I think that spot has just be soldered too many times. Im going to scrap this monitor also. Thank you for your assistance Sir

Have a couple of days off it then have think about it
Good Luck
Bob

[freakytiki4u]

Re: Dell E153FPB Back Light problem

What temparatures do you all use when soldering on these inverter boards? I think I may have used a lil too much. I use 800 degrees F and i get in and out as quickly as I can so I dont put too much heat to the board. I use a radio shack soldering station ( i know I know, LOL) and 840 degrees Farenheit is its max temp.

[freakytiki4u]

Re: Dell E153FPB Back Light problem

Have a couple of days off it then have think about it
Good Luck
Bob

I wont throw it away, just set it off to the side. lol, I found a place that I can buy a refurb inverter board for $40.00 and thats not a bad price but it doesnt compare to the rewards of learning to repair my own stuff.

[FredW]

Re: Dell E153FPB Back Light problem

Just to say thanks for the info,was given a Dell E153FPB with the indicator light flashing and got the c5707's off the interweb thingy,pulled the case apart as per your comments the inverter board was clean no burn marks but found that a couple of joints were very dry,dropped the transistors and replaced all 4 then reflowed all the joints areound the inverter,put the monitor back together and oh joy it worked been on test now for 48hours.

[jschiefer]

Re: Dell E153FPB Back Light problem

I am back, sorry i have been away for awhile. I replaced all four of the 5707's on my power board and its still not working. I am still having the problem with the monitor going on blinking white and then black. It does that a couple times and then stays black. With a flash light, i see nothing.

I turned toward the diode trouble shooting. I have the board unpowered and was using a diode check, then reversing the leads. On some of them (all but two) i got a reading with the probes in both directions. What are the chances of all of these being bad. Thanks again for the help.

[jschiefer]

Re: Dell E153FPB Back Light problem

OKAY! I got the monitor to show me a picture but now the ccfl go on for like 3 seconds when i first turn it on, then it goes off again, but i can clearly see the image on the monitor, just no brightness

[PlainBill]

Re: Dell E153FPB Back Light problem

OKAY! I got the monitor to show me a picture but now the ccfl go on for like 3 seconds when i first turn it on, then it goes off again, but i can clearly see the image on the monitor, just no brightness

Good! You've at least got it to show a picture. There are several possible causes for the '2 seconds to black' problem. If you haven't resoldered all the pins on the inverter transformers, do it now.

Next, there are several versions of the power supply / inverter board in this monitor. I will need a picture of the back of yours to be able to identify test points.

PlainBill

[nostebbi7]

Re: Dell E153FPB Back Light problem

Hi new to this forum but have already found a boat load of valuable information - but I need more.

I have a Dell E173 FPB LCD Monitor which has developed a bad flicker.

I've opened it up thinking I would find some bulging capacitors but all look fine and I cannot see any area's in need of soldering.

The monitor flickers randomly and I've tried with a couple of PC's and Laptop but to no avail.

It also flickers when not connected to anything as you can see by the video that I've posted on Youtube.

http://www.youtube.com/watch?v=FzgP9t3GNZM

Anyone got any idea's?

Thanks in anticipation of some assistance

[PlainBill]

Re: Dell E153FPB Back Light problem

Hi new to this forum but have already found a boat load of valuable information - but I need more.

I have a Dell E173 FPB LCD Monitor which has developed a bad flicker.

I've opened it up thinking I would find some bulging capacitors but all look fine and I cannot see any area's in need of soldering.

The monitor flickers randomly and I've tried with a couple of PC's and Laptop but to no avail.

It also flickers when not connected to anything as you can see by the video that I've posted on Youtube.

http://www.youtube.com/watch?v=FzgP9t3GNZM

Anyone got any idea's?

Thanks in anticipation of some assistance

It MIGHT be the logic card; the panel electronics board (usually under a cover on the LCD panel itself) is more likely, but I would bet it's a bad connection on one of the ribbon cables between the panel electronics board and the side of the panel itself. If you can locate the point where exerting pressure makes it work better, you MIGHT be able to put something in place to keep it working.

PlainBill

[RacerX10]

Re: Dell E153FPB Back Light problem

I have an E153FP (about 20 of them, actually) and of the (3) I've tried to repair so far with this kit :

http://cgi.ebay.com/ws/eBayISAPI.dll...m=220488756040

only (1) has worked. I've replaced the 6 transistors, 1 fuse and re soldered the leads on the 2 transformers.

With 2 of the monitors, they are still flashing "ON" for a sec properly working, then the back-light goes dead but the power light stays on and you can barely see the test pattern image on the display.

Is there something else I should be checking on these boards ?

Thanks !

[PlainBill]

Re: Dell E153FPB Back Light problem

I have an E153FP (about 20 of them, actually) and of the (3) I've tried to repair so far with this kit :

http://cgi.ebay.com/ws/eBayISAPI.dll...m=220488756040

only (1) has worked. I've replaced the 6 transistors, 1 fuse and re soldered the leads on the 2 transformers.

With 2 of the monitors, they are still flashing "ON" for a sec properly working, then the back-light goes dead but the power light stays on and you can barely see the test pattern image on the display.

Is there something else I should be checking on these boards ?

Thanks !

There are a lot of possible causes for the 'Two Seconds To Black' problem. You've already seen one of them - bad transistors. Other possible causes include bad (aging or broken) CCFLs, bad wiring to the CCFLs (especially the solder joints at the ends of the tubes), open or shorted turns on a transformer, bad capacitors, and defective components in the backlight safety circuit.

Eliminating the CCFLs and wiring is easy. Take your good board and try it in all of the other monitors. Tag any that don't work as suspected bad CCFLs or wiring.

Next, try the boards from the monitors with bad CCFLs / wiring in your good monitor. Tag any that don't work as needing further testing. Now try to match up as many good monitors with good boards as you can. Save one or two working sets for comparison purposes.

Now you can get down to the real troubleshooting. Open up each monitor to the point you can check each CCFL and wiring. Measure the resistance of the secondaries of every inverter transformer. Check the 6 transistors and the fuse on each board. Replace any caps that show any signs of bulging. Any boards that are still bad are candidates either for more advanced troubleshooting or for use as parts donors.

PlainBill

[kenpospeed]

Re: Dell E153FPB Back Light problem

I was wondering if I can use C5707 transistors for the C5706 ones, because the one on my board are C5706