electronics experts - help me out

[Silver86]

so i had an lcd monitor die on me... did some google researching and saw a lot of topics on bad capacitors. (power button was flashing... no picture on screen)

here are pics of some caps in question... are these bad (bulged top section)

http://i5.photobucket.com/albums/y184/blackaccordlx/IMGP9620.jpg

http://i5.photobucket.com/albums/y184/blackaccordlx/IMGP9619.jpg

you can see that theyre slightly bulged... bad caps?

[fivonut]

Looks like they got hot to me.

[PureSound15]

They bulged but don't look terrible (I've seen some that leak - or the top is completely open) but caps are usually the cause of LCD monitor failure, from what I've seen. Just replace em!

[Silver86]

where would i go about picking caps up? i know radio shack doesnt carry stuff like that in-store anymore.

[wikked]

Radio Shack does indeed carry caps.

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=capacitors&origkw=capacitors&sr=1

In-store as well.

[Silver86]

Radio Shack does indeed carry caps.

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=capacitors&origkw=capacitors&sr=1

In-store as well.


well isnt that good news...

edit: well... turns out that the stores near me (grafton and WB) dont have any, but i can order site to store. they also dont carry any of the caps im looing for... 330uf 35v and 680uf 16v

[WhatsADSM]

well isnt that good news...

edit: well... turns out that the stores near me (grafton and WB) dont have any, but i can order site to store. they also dont carry any of the caps im looing for... 330uf 35v and 680uf 16v

You can always get caps that are rated to a higher voltage. i.e. you could get caps that were 330uf 50v and 680uf 50v

The farad rating is a little more important as it is many times the deciding factor in a time constant or damping factor for that circuit. Try to make sure that you pick the same (or very close) farad rating.

In any case it was a little hard for me to judge the lead spacing on those caps so I just picked 5mm. You can make it work anyways by just bending the leads a little bit if need be:

Just click the links, add as many as you want to the order and checkout.

Aluminum electrolytic 330uF 50V long life (105* C), 56 cents a peice:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P13133-ND

Aluminum electrolytic 680uF 35V long life (105* C), 65 cents a piece:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=565-1580-ND

[WhatsADSM]

Oh yea and when you install them electrolytics HAVE A SPECIFIC POLARITY!

So when you take the old capacitors out note which lead is the negative lead. The cap. will have a clearly indicated stripe on it with a "-". Make sure when you install the new cap that you put the negative lead in the same spot. If you reverse the polarity the cap will explode once it is energized with a signficant amount of reverse voltage.

[Prince Valiant]

Pfft. Electrolytics. Sounds like you're making up words to me.


:goof

[Silver86]

Oh yea and when you install them electrolytics HAVE A SPECIFIC POLARITY!

So when you take the old capacitors out note which lead is the negative lead. The cap. will have a clearly indicated stripe on it with a "-". Make sure when you install the new cap that you put the negative lead in the same spot. If you reverse the polarity the cap will explode once it is energized with a signficant amount of reverse voltage.



thanks for the info... i did surprisingly find a bunch of videos on youtube about replacing caps on dead LCDs and i did know about the polarity.

i was hoping on being able to pick these up locally... im kind of impatient and wanted to give this a shot before my weekend ends. but i guess its not really a big deal... have you ordered parts from that place before? and the 2 links you posted will work (i take it that youve done this before?)

[BoosTT]

Heres the story... A chinese company stole a prototype cap forumla... they made a bunch of caps that did expand/fail over time. A lot of early 2000's motherboards failed because of them.

Problem is you can't find the same value replacements easily. Just get a new monitor (I can tell its old, because they stopped making those caps a few years ago). I got some caps off ebay, but they were a bitch to solder. The leads were too big to find in the holes. You can try digikey.com or mouser.com for them.

[Silver86]

Heres the story... A chinese company stole a prototype cap forumla... they made a bunch of caps that did expand/fail over time. A lot of early 2000's motherboards failed because of them.

Problem is you can't find the same value replacements easily. Just get a new monitor (I can tell its old, because they stopped making those caps a few years ago). I got some caps off ebay, but they were a bitch to solder. The leads were too big to find in the holes. You can try digikey.com or mouser.com for them.


thing is... its not that old of a moniter... 2007 was the manufacture date.

[WhatsADSM]

thanks for the info... i did surprisingly find a bunch of videos on youtube about replacing caps on dead LCDs and i did know about the polarity.

i was hoping on being able to pick these up locally... im kind of impatient and wanted to give this a shot before my weekend ends. but i guess its not really a big deal... have you ordered parts from that place before? and the 2 links you posted will work (i take it that youve done this before?)

I have ordered from Digikey more times than I can keep track. There distribution system is probably one of the most amazing on the planet. The stock hundreds of thousands of different part numbers, and they keep track of the exact quantity of each. You can order a single resistor for 2 cents and it will be accounted for. Also when you order assuming you do it on monday, it will likely be shipped out within an hour or 2 even if you order 3 caps. It's truly amazing :wooo

And yes the 2 links I posted will work, they are the specs you are looking for... and FWIW they are also much higher quality than anything at Radio Shack anyways.

[1320PNY]

+1 on DigiKey. I've used them for years. I ordered some light pipes, like $1.75 in parts and I got them in two business days. No matter how small your order, great service.

[Silver86]

awesome... looks like ill be ordering then on monday... thanks for the help fellas!

[Silver86]

wish me luck... got them soldered in... about to power it up... hope all goes well :banana1:


edit: WOOT! fired right up!

[WhatsADSM]

A few dollar fix (all shipping) and your LCD is back in business :) Great to hear!

[1320PNY]

A few dollar fix (all shipping) and your LCD is back in business :) Great to hear!:thumbsup

[Silver86]

Aluminum electrolytic 680uF 35V long life (105* C), 65 cents a piece:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=565-1580-ND


bring this back from the dead. as i have another dead moniter that im gonna fix.

the 680uf 35v above are out of stock till november (estimated time)... will these work?

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P10302-ND

[BoosTT]

Yes. Same thing expect only half the life span.