Please help me decide replacement capacitor

[biatche]

ORIGINAL CAPACITOR:
EPCOS 1000uF 16v 10x20 0.054ohm 1100mA

REPLACEMENT:
choice 1: 0.019ohm 2180mA
choice 2: 0.052ohm 1220mA
choice 3: 0.023ohm 1820mA

which to pick?

[Pentium4]

Re: Please help me decide replacement capacitor

What did the capacitor come out of? It depends but I would choose the 2nd option as it's closest to the original specs. What brand are the replacements you are looking at?

[biatche]

Re: Please help me decide replacement capacitor

monitor

replacement caps: panasonic

Some people on IRC are telling me choice1/3 is better.

[mariushm]

Re: Please help me decide replacement capacitor

Considering you don't say the brands, we could only guess.

The other choices may be better, for some specific uses (vrm circuitry in motherboards, more complex power supplies), but if your original capacitors had those specs, you don't gain much by using capacitors with way better specs.

On the contrary, those capacitors with better specs may have shorter life (let's say 1000h@105c versus 2-4000h@105c for option 2) and life rating actually has more relevance in some cases. like monitors where everything is closed with little ventilation room.

[biatche]

Re: Please help me decide replacement capacitor

choice 1: 0.019ohm 2180mA PANASONIC
choice 2: 0.052ohm 1220mA PANASONIC
choice 3: 0.023ohm 1820mA PANASONIC

[PeteS in CA]

Re: Please help me decide replacement capacitor

The point P4 and mariush are trying to get across is that this is not as simple as you might hope. Value, case size, impedance, ripple current rating, brand, and circuit function (not just the product its used in) all matter. Try being a little patient and maybe learn a little from guys who have been doing this for years or even decades.

[biatche]

Re: Please help me decide replacement capacitor

Hm, perhaps its my misunderstanding.. but would you mind telling me when replacing PSU / monitor PSU caps, what are the things to look at then for a more prolonged lifespan? Is it to check those 1000h@105c? I've went ahead and purchased 10,000 hours @ 105c with lower ESR, higher ripple... Please correct my mistakes

[Pentium4]

Re: Please help me decide replacement capacitor

That is good, that's what you want is a long life span @ 105C, low ESR, and high ripple. As long as they fit then those caps should be perfect. Try and get the dimensions as close as possible. But just to be sure what series are those Panasonic caps?

[biatche]

Re: Please help me decide replacement capacitor

I've already purchased and received the following (for various monitor repairs):

EEUFR1E102 CAPACITOR, RADIAL, 25V, 1000UF EEUFR1E102
EEUFR1V681 CAPACITOR, RADIAL, 35V, 680UF, 20% EEUFR1V681
EEUFM1A102 CAPACITOR, RADIAL, 10V, 1000UF EEUFM1A102
EEUFR1E821 CAP, ALU ELECT, 820UF, 25V, CAN EEUFR1E821

They are all panasonic.

I've fixed a Samsung 931BW, and a AOC 2219VG.

I just did a LG-L226WTQ-PF. The screen power LED now goes standby/lights up normally when the PC turns on. The lighting is obviously turned on but there's no picture on screen. What could this mean? I should note my solder work was bad and I left burns on the pcb. ?copper? is exposed.... should i post a picture?

Also, I've carelessly not noted the 2-pin colors on some other monitors and have forgotten their positions. What happens when the cable is incorrectly plugged?
it's either:

[red-white] [blue-black] [blue-black] [red-white]
or
[red-white] [blue-black] [red-white][blue-black]

[mariushm]

Re: Please help me decide replacement capacitor

The capacitors you chose are very good.

Use a flashlight or something bright and see if you can see something on the screen when you're supposed to be able to see something. If so, there's a problem with the backlight, either you didn't solder something properly or the problem was more than just a capacitor replacement.

Please post pictures, as clear as possible.

As for the cables, if you put them incorrectly you can cause a short circuit, blowing up capacitors or fuses on the boards. Or it could be nothing, depending where those cables go.
If you post pictures as clear as possible, we may be able to tell you where the cables go or in what order. Usually there are hints on the boards or the connectors are in a particular format.
Or someone here may have worked on that monitor (or a monitor with a board similar to yours) and remembers the cable layout.

[biatche]

Re: Please help me decide replacement capacitor

2 monitors don't seem to be capacitor issue! Hmm.. they display for just a split second then picture disappears. By selecting the source from the panel, it displays again for a split second then disappears.

[mariushm]

Re: Please help me decide replacement capacitor

It's quite possible.

I'll give you a simple example: the inverter circuit which converts 12-30v from the power supply to 700-1500v required by the CFL lamps (the light tubes) has a protection mechanism.
The controller will turn off the lamps after a timeout period, if one of the lamps doesn't seem to start or if the lamps demand too much current (which happens when the lamps are very old).
It's possible for a lamp to not start because one of the wires going to it becomes loose due to constant heating and cooling down cycles - it happens often. If a wire is loose, the circuit is interrupted and the controller doesn't detect the two lamps using power so it stops completely after that time out period.
If a lamp is very old and demands a lot of current, the controller could also detect that and stop itself to protect those rectangular transformers from overheating, or to protect other components in the inverter circuit.
Since there are usually two outputs and usually there are tubes (lamps) connected to each output, the controller could stop itself even if one lamp is faulty.

Capacitors can go bad for example when one or several lamps go bad in time and demand more current from the controller which in turn could overload the controller and get it hot and in turn puts more stress on the capacitors... could also be the other way around... the capacitors going bad and messing up the inverter (and you may have soldered the new capacitors badly so it still doesn't work) ... who knows.

There's lots and lots of possibilities.

Please get back to use with pictures, as clear as possible.

[biatche]

Re: Please help me decide replacement capacitor

There are 2 monitors I'm unable to repair:

LG L226WTQ-PF:
capacitors replaced
bad soldering work, pictures to come soon. waiting for camera
light tubes go on and off normally when monitor is on/off, however, no picture can be seen

Samsung 931BW:
nothing's changed.
capacitors not even bulging, looks good.
picture displays a split second then disappears. selecting source causes it to display for a second then disappears again.
found someone else with this issue. this does not look like easy work:
http://www.jestineyong.com/samsung-9...second-solved/

[biatche]

Re: Please help me decide replacement capacitor

LG L226WTQ-PF (MY BAD SOLDER WORK):


Backlight is on but no display.
Pressing on menu button doesn't show anything. Actually none of the buttons do a thing -- zoom, source, menu, etc etc.
Turning on and off does show the LG logo middle of the screen. Very clear.
Also displays source at top right corner. Very clear.

[biatche]

Re: Please help me decide replacement capacitor

LG L226WTQ-PF more pics and vid:

http://cockcrotch.com/tmp1/tmp-bunder-1.jpg
http://cockcrotch.com/tmp1/tmp-bunder-2.jpg
http://cockcrotch.com/tmp1/tmp-bunder-3.wmv

[biatche]

Re: Please help me decide replacement capacitor

SAMSUNG 931BW:
http://www.cockcrotch.com/tmp1/tmp-brownspots-1.jpg
What are these brown spots? there are several spots like this. should it be resoldered? could this be the cause?

[mariushm]

Re: Please help me decide replacement capacitor

The LG looks fine.
If it shows those "no signal" messages and the backlight stays on that long, everything's good.

Since the monitor has both vga and dvi, make sure it's switched to the proper source (that may be the cause for the no signal message).

If you're using a dvi to vga adapter, make sure the video card's dvi connector outputs analogue signal - some video cards have two dvi ports but only one outputs vga.

If you're sure the monitor is supposed to get a signal (you can test this by checking with another monitor), then something between the vga or dvi connector and that large chip could be damaged. Possibly due to ESD or a short circuit etc.
The board otherwise looks fine to me.

If you have a multimeter, put it in DC voltage measurement and measure the voltage on IC702 and IC703 ... Black probe on center pin, red on the first, last and the tab (that large part soldered to pcb like a heatsink)
It's unlikely one of those 2 voltage regulators is bad but it doesn't hurt to try.

The Samsung monitor, it could use some cleaning.. get some cloth and remove the dust.
The brown stuff could be flux left from the wave soldering process, it's not something that would cause problems.
However, there are some solder joints that look like they could be cracked or cold solder joints (from vibrations, heat-cold cycles etc).. the ones at the top and the one by R76 and C9 don't seem so good to me.
It wouldn't hurt to at least reheat that solder with your iron tip (ideally remove the solder and put new solder).
Clean up the board and post pictures of the whole board and pictures with different sections more zoomed in like in the lg pictures