Benq FP757, replacement transistors only worked for three days

[bluesmoke]

I had a black screen on my Benq FP757. I replaced all four c5707 transistors on it that are known to fail and all was good for about three days. Not it's back to a black screen again.

Is there something else failing that would cause the transistors to fail? I'm not much of an electrician, just a noob with a multimeter and a soldering iron.

[Bobdee]

Re: Benq FP757, replacement transistors only worked for three days

I had a black screen on my Benq FP757. I replaced all four c5707 transistors on it that are known to fail and all was good for about three days. Not it's back to a black screen again.

Is there something else failing that would cause the transistors to fail? I'm not much of an electrician, just a noob with a multimeter and a soldering iron.

You need to resolder the 4 inverter transformers, all the legs of each one, these are possibly reason transistors failed in the first place
IT may be only one has failed so you can replace one of the good old ones as they never all fail plus possibly a new fuse will be needed on inverter

[EGuevarae]

Re: Benq FP757, replacement transistors only worked for three days

You need to resolder the 4 inverter transformers, all the legs of each one, these are possibly reason transistors failed in the first place
IT may be only one has failed so you can replace one of the good old ones as they never all fail plus possibly a new fuse will be needed on inverter

I agree. Replacing the 5707s without resoldering the transformers is almost like not replacing them ..... in fact worse, as you may have to remove the 4 pieces and see how many went south ....

[starmaxpc]

Re: Benq FP757, replacement transistors only worked for three days

i have one of these models which also had a bad lcd. a ton of vertical lines plus no power when powered on, blue power button turns yellow etc. i replaced the 4 c5707's, 2 fu9024n's and the 3 amp fuse and also the lcd was replaced. i now have a red tint to the screen and pictures arent really clear. like photo quality clear. is it possible that the cable on this is not compatible with the newer lcd and causing the red tint?

[PlainBill]

Re: Benq FP757, replacement transistors only worked for three days

i have one of these models which also had a bad lcd. a ton of vertical lines plus no power when powered on, blue power button turns yellow etc. i replaced the 4 c5707's, 2 fu9024n's and the 3 amp fuse and also the lcd was replaced. i now have a red tint to the screen and pictures arent really clear. like photo quality clear. is it possible that the cable on this is not compatible with the newer lcd and causing the red tint?

It's possible, but more likely the red tint is die to CCFLs that are dying.

PlainBill

[EGuevarae]

Re: Benq FP757, replacement transistors only worked for three days

It's possible, but more likely the red tint is die to CCFLs that are dying.

PlainBill

I agree. Red/pink hue is the signal of dying lamps