xplio computer monitor

[scampo77]

i posted on a nother thread and got kind of hijacked so i thought i would start my own here. here is what i already posted

Quote:
Originally Posted by scampo77
i came across this thread on a google search and i am very excited to be a part of this forum. i am very new at this but i really want to learn how to fix my problem. i have the same same power supply it is slightly differnt so i included a picture .i have different symptoms, mine is just dead. i seem to have DC voltage for the first bit of the board then when it reaches the blue transformer (P/N SPW-055 Rohs) i have +-160vdc going in and nothing coming out. also next to it there is a cap (JNC JM472M) and a 4 leg zener diode (P/N 817B)all have voltage on one side and not the other.

im not too sure what i should measure next or what to pull out next

any help would greatly be appreciated. please keep in mind im willing to learn but im new to this


Welcome to the forum! Good initial try at trying to figure what's going on. Here's what you need to do:

1) post some photos (top and bottom) of the entire power board and logic board (the board you plug your video cable into) per PlainBill's links on post #45

2) I think you're measuring the 160VDC off the bridge rectifier. This should be the same voltage across the 450V main capacitor.

3) looks like you're getting voltage to the PWM controller chip.

4) when you push the power button, does it show any activity?

5) any flash on the screen when you push the power button?

6) any other observations will be helpful.

[retiredcaps]

You can start by answering questions 1 through 6.

[scampo77]

yes the 160dcv is the same as the big cap

the power LED just keeps blinking green

i have zero volts at either inputs of the high voltage transformers

and no blinks of brightness or attemps at the moniter display lighting up or powering on even for a second

when i toggle or hold down the power button it seems to make no difference at all in the intervals of the blinking green LED it comes on for about 5 secs then off for .5 sec and just keeps cycling

[retiredcaps]

You have at least 2 bloated bad caps (just right of the schottky diodes). This is why we always ask for pictures.

[retiredcaps]

Most here will suggest you replace all the electrolytic caps on the power board except the largest one which rarely, but not never, fails.

If you live in the USA, you can follow PlainBill's instructions to order Panasonic FM caps (FC is a 2nd choice). See

http://www.badcaps.net/forum/showpos...33&postcount=2

[scampo77]

sorry, your quick!! i thought i could get up both posts before someone would answer. i figured it would be too long for one big post

[scampo77]

thanks for all the help i will get ordering right away

[retiredcaps]

The diodes that are mounted on the heat sink give off a fair bit of heat. Caps die from heat. So the closest one take the full brunt of the heat.

The diodes produce the 5V DC for the logic board and another voltage for the inverter section. If those caps are on the 5V rail and are bad, the logic card will not get proper voltage to operate normally.

[scampo77]

i got my new caps today and before i put them in i have a couple questions

1, is there a positive negative on these caps or is there a forward direction? i mean can i install them backwards?

2, why are they a different size from the orginals? some of the new ones ill need to lay down to get them in, is this normal do i need to order by dimension aswell as capacitence?

3 the guy at the store said that the voltage rating on a cap is a rating that the cap can operate "up untill". is it true that i can use a 25v220uF in place of a 16v220uF ?

[jetadm123]

Originally Posted by scampo77

i got my new caps today and before i put them in i have a couple questions

1, is there a positive negative on these caps or is there a forward direction? i mean can i install them backwards?

2, why are they a different size from the orginals? some of the new ones ill need to lay down to get them in, is this normal do i need to order by dimension aswell as capacitence?

3 the guy at the store said that the voltage rating on a cap is a rating that the cap can operate "up untill". is it true that i can use a 25v220uF in place of a 16v220uF ?

1. Yes, these caps have a pos and neg lead. Neg is usually a stripe running down the side of the cap. Either draw a picture of the cap placement before you start, or replace them one at a time. Do both.

2. Different manufacturers make different sizes. No harm in using a different height/diameter as long as it fits. Next time, measure the old caps before you buy.

3. Yes, you can use a higher voltage cap. A higher voltage cap could be physically larger.

[retiredcaps]

Originally Posted by scampo77

2, why are they a different size from the orginals? some of the new ones ill need to lay down to get them in, is this normal do i need to order by dimension aswell as capacitence?

PlainBill's last instructions on how to order was to make sure to check the dimensions.

If you bought them for a local store, take them back and see it they will exchange it for you?

[PlainBill]

Originally Posted by scampo77

i got my new caps today and before i put them in i have a couple questions

1, is there a positive negative on these caps or is there a forward direction? i mean can i install them backwards?

2, why are they a different size from the orginals? some of the new ones ill need to lay down to get them in, is this normal do i need to order by dimension aswell as capacitence?

3 the guy at the store said that the voltage rating on a cap is a rating that the cap can operate "up untill". is it true that i can use a 25v220uF in place of a 16v220uF ?

When I see something like this I wonder "What brand and series of caps did you get?" 95% of electronics will function properly with general purpose caps. The SMPS (Switching Mode Poer Supply) found in monitors is not part of that 95%. They require low ESR caps to work properly. A common result of using general purpose caps is 'two seconds to black'. An early failure is also likely. I understand there are areas where high quality caps are available over the counter, those are quite rare.

PlainBill

[scampo77]

this is my first repair and i have learnt i should get the actual quality caps from MCM but for this repair i would like to see if i can make this work off of the 3$ worth of caps i got from the local electronics guy. i suspect i will learn a great deal more before im done even soldering all these in. at this point ill even take a 3 secs to black as a victory

my questions are about the positive and negative leads on these caps. they all seem to have a stripe on them but some have a "-" and some have a "+" on the strip and some have a rectangle. what does this mean?

my board has pretty clear +- marks and even the "parking spot" is painted half black to signify the neg side (im assuming).

do i line up the stripe? line up the rectangle or +- signs? or is there such a thing as positive or negative cap?

[retiredcaps]

Originally Posted by scampo77

do i line up the stripe? line up the rectangle or +- signs? or is there such a thing as positive or negative cap?

See post #8

http://www.badcaps.net/forum/showthread.php?t=485

[retiredcaps]

PCBONEZ explains ESR, ripple, etc so you can understand why low ESR caps are required and why buying quality matters ...

http://www.badcaps.net/forum/showpos...30&postcount=7

[scampo77]

is there an affordable meter i can buy to test the important specs of capacitors? i am curious which one of these caps failed and which ones i can throw into my toolbox and save for later if i am ever in a pinch and need one.

i have a cheap meter right now that has a "cap" setting but i am either using it wrong or dont understand what it is telling me. i was hoping to find a meter that says "440uF" or so and so ESR. or whatever else is relivent info.

i ordered parts from mcm and i managed to get this moniter working "for now" off of my dollar store caps and the help of everyone here so a big thank you to everyone!!!!

i have a very old scope that i was told i could use to test caps but im not sure how or even if its true any advice would be appreciated.

[retiredcaps]

Originally Posted by scampo77

is there an affordable meter i can buy to test the important specs of capacitors?

From what I know, most of these ESR meters range from $60 to $300.

i have a cheap meter right now that has a "cap" setting but i am either using it wrong or dont understand what it is telling me.

Some multimeters only measure caps up to a certain uF like 100uF. So anything above that might give out of range.

What brand and model number is your multimeter?

i ordered parts from mcm and i managed to get this moniter working "for now" off of my dollar store caps and the help of everyone here so a big thank you to everyone!!!!

I was just at 2 dollar stores here in Canada and neither of them sell caps. I did pickup a decent 9 LED flashlight and ball pump for $1.25 each.

[EGuevarae]

Originally Posted by scampo77

is there an affordable meter i can buy to test the important specs of capacitors? i am curious which one of these caps failed and which ones i can throw into my toolbox and save for later if i am ever in a pinch and need one.

i have a cheap meter right now that has a "cap" setting but i am either using it wrong or dont understand what it is telling me. i was hoping to find a meter that says "440uF" or so and so ESR. or whatever else is relivent info.

i ordered parts from mcm and i managed to get this moniter working "for now" off of my dollar store caps and the help of everyone here so a big thank you to everyone!!!!

i have a very old scope that i was told i could use to test caps but im not sure how or even if its true any advice would be appreciated.

Mostly, you'll find them to be bloated, or if no signs of damage at all, they will be Capxon or other bad/failing (crap) brand/series.Sometimes you'll find a change-on-sight cap.For that, you don't really need an ESR meter,unless you plan to do a living from this, maybe ...

[Mikeley]

Hi,
Nice video tutorial on Capacitor basics... http://www.youtube.com/watch?v=YCSNWi3UHf4&feature=fvw

[scampo77]

here is my meter its a word doc instruction manual.

http://sitebuilder.tradeeasy.com/sho.../52-0052EN.doc

its just a cheap meter from canadian tire #52-0052-2. its just the only one i have that has a cap setting, it seems that every time i try to meause i get a different reading. im not sure if i am doing something wrong or if the meter is junk. i also have a true RMS meter that i use for everything else.

i was just kidding about getting about my caps from the dollar store they came from the local electronics supply guy in montreal where the tech support usually goes as far as about the 16 year old kid saying, "capacitors are round and have legs on them" so its not that far off the dollar store.