HP lcd L1502 15"

[Th3_uN1Qu3]

Re: HP lcd L1502 15"

That's the logic board. It's kinda obvious that it won't do it without the logic board connected, since the logic is what instructs the inverter to turn on.

[leov]

Re: HP lcd L1502 15"

Hi PlainBill,

Thanx for taking time to look into this for me. I used united chemi-con caps from Digi-key.


Also, I found out that the problem occurs when I connect little circuit board that has VGA connector on it. If its not connected, there is no clicking heard on the big board.

[leov]

Re: HP lcd L1502 15"

Hi did you test the transistors that you have arrowed (probably 5707 or 5706 markings on them )
Also did you resolder the 4 x transformers

If you check threads that deal with Dell 172 monitors they have the same type of board and have the same symptoms

Hi sabre, Thank you for replying to my post. I appreciate your help. The transistors are 5707. How do I go about testing them? I have very limited understanding of these things. I did not resolder the transformers.

[PlainBill]

Re: HP lcd L1502 15"

Hi guys. I am very new to this, but was hoping you would help me fix my lcd. Originally, the screen started to turn itself off randomly. I was able to restart it, but after few days it shut down and I was not able to bring it back to life. I replaced all 25V 470 uF caps on this board. They were not blown, but looked like they were starting to "inflate". (sorry, i am not sure what the proper terminology is to describe it). That did not fix the problem though. When I connect the power cable I can hear a clicking noise coming from the parts that I circled on the picture. They turn really hot if the power cable is connected. Would someone please tell me what I should do next? How do I go about testing the other components on the board? Thank you.

This is a classic example of the problems with these monitors. As sabre504 said, replace both transistors (2SC5707). Also resolder all pins on the 4 inverter transformers. Just for luck, I'd also replace the cap that was clicking.

What brand and series capacitors did you use as replacements for the bulging caps?

PlainBill

[sabre504]

Re: HP lcd L1502 15"

Hi did you test the transistors that you have arrowed (probably 5707 or 5706 markings on them )
Also did you resolder the 4 x transformers

If you check threads that deal with Dell 172 monitors they have the same type of board and have the same symptoms

[leov]

Hi guys. I am very new to this, but was hoping you would help me fix my lcd. Originally, the screen started to turn itself off randomly. I was able to restart it, but after few days it shut down and I was not able to bring it back to life. I replaced all 25V 470 uF caps on this board. They were not blown, but looked like they were starting to "inflate". (sorry, i am not sure what the proper terminology is to describe it). That did not fix the problem though. When I connect the power cable I can hear a clicking noise coming from the parts that I circled on the picture. They turn really hot if the power cable is connected. Would someone please tell me what I should do next? How do I go about testing the other components on the board? Thank you.