hp pavillion vf51

[dood]

Re: hp pavillion vf51

hpaca509- Try plugging the adaptor into the monitor and testing the input voltage on the board. This is to make sure that it doesn't short the power supply when plugged in.

[hpaca509]

Re: hp pavillion vf51

where do i put my pins to see if power is an issue

[hpaca509]

Re: hp pavillion vf51

well after retracing all my step it turns out fb500 is out and the going over the pins i stil got zero.

[retiredcaps]

Re: hp pavillion vf51

well after retracing all my step it turns out fb500 is out and the going over the pins i stil got zero.

Please clarify "fb500 is out".

What is the exact ohms reading on fb500?

[hpaca509]

Re: hp pavillion vf51

instead of the .3 ohms you told me i got zero
but the others were .3

[hpaca509]

Re: hp pavillion vf51

on the fuse thing fb500 through fb503

[retiredcaps]

Re: hp pavillion vf51

instead of the .3 ohms you told me i got zero
but the others were .3

I still don't know what you are referring to, but let's try this again.

A good fuse measures 0.3 ohms with using resistance tests (power off, unplugged). Some multimeters will say 0L when the resistance is too high to measure (especially if your multimeter is manual range and set to 200 ohms). For a fuse, this is an open or bad fuse.

So if FB500 measures 0L, it is a bad fuse. That would explain why you have no power.

0 (zero) and 0L are two different things. 0 is zero. 0L means infinity.

[hpaca509]

Re: hp pavillion vf51

i got a plain zero. now does that mean i have to replace fuse they are so small how do you replace that.

[retiredcaps]

Re: hp pavillion vf51

i got a plain zero. now does that mean i have to replace fuse they are so small how do you replace that.

Can you post a picture and model number of your multimeter?

If you put your multimeter on the lowest ohms setting and touch the red probe and black probe together, what reading do you get? What is the exact ohms reading?

To replace a small fuse, I like these videos on soldering by CuriousInventor

http://www.youtube.com/watch?v=3NN7UGWYmBY

Fuses can be found at digikey.com if you are in USA.

[PlainBill]

Re: hp pavillion vf51

Ahh, guys. FBxxx usually means 'Ferrite Bead'. Fxxx is a fuse; PFxxx is a Picofuse.

PlainBill

[retiredcaps]

Re: hp pavillion vf51

Ahh, guys. FBxxx usually means 'Ferrite Bead'. Fxxx is a fuse; PFxxx is a Picofuse.

PlainBill

Aren't some fuses marked FB for "fast blow"?

edit: F500 is definitely a fuse though. I think it says 3 for a 3A fuse.

[hpaca509]

Re: hp pavillion vf51

ok so i have done all the procedures to make sure where my problem is a have established from the info given from you all that my fuse is blown it was FB500 the quote was from retiredcaps
"2) Check all the fuses on the board with power off and unplugged. They should measure 0.3 ohms. I see (thanks to the great pic) FB500, FB501, FB502, and FB503 right by P500"

i then retiredcaps you told me to "Put your black probe on pin 3 (ground). Put your red probe on pin 1. Record DC V reading. Now move your red probe over to pin 2. Record DC V reading." I did this and established that maybe my 680uf cap looked suspicious.

should i just but those two items and see how it goes from there or can i bypass these two things and see what else to replace or what should my next step be?

[retiredcaps]

Re: hp pavillion vf51

ok so i have done all the procedures to make sure where my problem is a have established from the info given from you all that my fuse is blown it was FB500 the quote was from retiredcaps

If your fuse F500 reads 0L (infinity), that is definitely a bad fuse. Please upload a picture brand/make and model number of your multimeter. The manual should tell us what it will display for infinity or out of range.

i then retiredcaps you told me to "Put your black probe on pin 3 (ground). Put your red probe on pin 1. Record DC V reading. Now move your red probe over to pin 2. Record DC V reading." I did this and established that maybe my 680uf cap looked suspicious.

Yes. This was to test the voltage regulator. I then speculated that the 680uF cap was bad because we were not seeing 12V DC. HOWEVER, that was based on the assumption that F500 fuse was good. If the fuse is bad, it is possible that the 680uF is good.

should i just but those two items and see how it goes from there or can i bypass these two things and see what else to replace or what should my next step be?

I wouldn't advise bypassing the fuse (i.e. jumper or short it). The fuses are there for a reason.

There are a number of reasons why a fuse can blow. It can just be bad. It can blow because of lightning or surge. It can be bad because of too much current.

Another question. Is there a possibility that you have the incorrect AC adapter with the monitor? Many devices like laptops use similar looking AC adapters. The documentation for the LCD specifies 12V DC, but your adapter is 19V DC.

The voltage regulator documentation also specifies 12V DC.

PS. Stick with this. We are almost there to solving this problem.

[hpaca509]

Re: hp pavillion vf51

My multimeter is a Craftsman 82141
As for the AC adapter I bought this monitor when I was in High School in 2002-2003ish from Rent A Center(never buy from there). The adapter came from them and thats the only one i have used til now.

[hpaca509]

Re: hp pavillion vf51

so what is the order number for this fuse or where do i go from here

[retiredcaps]

Re: hp pavillion vf51

so what is the order number for this fuse or where do i go from here

Okay, now that I have read your multimeter manual, there are 3 more tests that must be done before ordering anything. If these 3 tests are consistent, then we can proceed to the next step. This is sort of the culumation of a number of questions from myself and others. These tests should not take more than 5 minutes.

Refer to attached diagram where I have circled the component in red. It is the white component with the number "3" on it. This is the only component we are going to test.

Put black probe in com jack, and red probe in v/ohm jack.

Test 1
======

Put your multimeter on the 200 ohms setting. Touch your black probe and red probe together and hold it until you get a steady reading.

Q1) What is the ohms reading?

Test 2
======

With power off and unplugged from the power adapter.

Leave the multimeter at 200 ohms. Put black probe on one side of the component circled and red on the other. Hold until you get a steady reading.

Q2) What is the ohms reading?

Test 3
======

Plug in your ac adapter into the monitor. Assemble everything and put all your ground screws back in.

Put your multimeter on 20 VDC. Put your black probe on the ground screw just right of P500. Put your red probe on one side of the component circled.

Q3) What is the DC V reading?

Now leave the black probe on the ground screw and move the red probe to the other side of the component circled.

Q4) What is the DC V reading?

[hpaca509]

Re: hp pavillion vf51

hello and good morning.
here are my results for the tests

Test 1. i got a reading of .3ohms then after about two seconds or so it goes to .2ohms.

Test 2. I got a reading of .3ohms then after about two seconds or so it stays on .2ohms steady.

Test 3. I got the same reading for both sides of component circled. It was 0.01.

[hpaca509]

Re: hp pavillion vf51

what is the fb500's part called it right under the circled item

[retiredcaps]

Re: hp pavillion vf51

Test 3. I got the same reading for both sides of component circled. It was 0.01.

Can you retest #3 again and make sure the ac adapter is plugged in and power on?

BTW, I have to head about in about 30 minutes so I won't be online for a few hours. We continue after I get back.

[hpaca509]

Re: hp pavillion vf51

i got zero on both sides