phillips lcd keeps blowing fuse

[tom66]

Re: phillips lcd keeps blowing fuse

Did you replace all four diodes?

[TimT]

Re: phillips lcd keeps blowing fuse

I just replaced the two.. but I can go ahead and replace the other 2 also

[tom66]

Re: phillips lcd keeps blowing fuse

It would be a good idea, also be very careful to get them in the same way they came out.

[TimT]

Re: phillips lcd keeps blowing fuse

I just replace the rest still blowing a fuse. I will buy a new power board! this has been a learning experence and I want to thank everyone for helping!

[Dgtech]

Re: phillips lcd keeps blowing fuse

I just read over this thread from start to end and all that you've tested so far was the diodes. Has anyone found a schematic on this set??? Is there a possible shorted FET? I'm sure theres a way to find the faulty component that's blowing this fuse? These problems are usually the easiest to find and cheapest to fix.

[Dgtech]

Re: phillips lcd keeps blowing fuse

Here, I did you a little legwork. Pull the first transformer (L1501) out of the circuit and see if your short is still there by checking ohms across from fuse (both sides) to ground. Here is a schematic of this primary side of your power supply.

[selldoor]

Re: phillips lcd keeps blowing fuse

I gave up on it because the pictures are so bad they hurt my eyes- chance of spotting anything is almost zero and there are none of the backs

[Dgtech]

Re: phillips lcd keeps blowing fuse

Better yet, I'll go as far as to just say, CHANGE SA1601 and SA1602. If you just pull these parts out I'll bet you that one of them is shorted.

This item is listed on the parts sheet as:

SA1601# SURGE ABSORBER 470V+-10PER



.

[Mark369]

Re: phillips lcd keeps blowing fuse

so becasue SA1601 is on the same line as R1609 you cant test it onboard.
is this right?

[TimT]

Re: phillips lcd keeps blowing fuse

I may pull these tonight or in the morning! Thank you!!

[Mark369]

Re: phillips lcd keeps blowing fuse

Here, I did you a little legwork. Pull the first transformer (L1501) out of the circuit and see if your short is still there by checking ohms across from fuse (both sides) to ground. Here is a schematic of this primary side of your power supply.

do you mean L1601 I don't know where L1501 is.

[Dgtech]

Re: phillips lcd keeps blowing fuse

You are correct, L1601, i read wrong. Look at my notes on the schematic below.
ALWAYS CHECK OHMS WITH THE POWER OFF.

[Dgtech]

Re: phillips lcd keeps blowing fuse

Here is another way to look at it from your point of view.

[TimT]

Re: phillips lcd keeps blowing fuse

I pulled 1601 and 1602 showing 00.2 ohms on both. did i need to test something on the board with these removed?

[Dgtech]

Re: phillips lcd keeps blowing fuse

I pulled 1601 and 1602 showing 00.2 ohms on both. did i need to test something on the board with these removed?

The measuring of the transformer is not going to be accurate for now. Read the ohms across R1609.

[TimT]

Re: phillips lcd keeps blowing fuse

R1609 is 0 no reading at all on meter. tested other resistors of same type tested good. pulled C1602 dead 0 on meter. wanted to make sure i was testing the cap correct. tested on new cap. new cap test ok! so bad cap and resistor?

[Mark369]

Re: phillips lcd keeps blowing fuse

so i would think c1602 and r1609 is bad.
what setting did you have your meter on. 20M, 200K, 20K, 200?
and when you measured they were out of the board right. you tested in both directions?

[TimT]

Re: phillips lcd keeps blowing fuse

the meter was set to 200. I measured the resistor on the board the capacitor out of the board.

[tom66]

Re: phillips lcd keeps blowing fuse

200 - "horseshoe" or 200 - V?

[TimT]

Re: phillips lcd keeps blowing fuse

horseshoe