Soyo 24" stopped, help!

[inaliz]

Hello All,

This all started after I got back from xmas vacation. Came back home turned on my computer and my DVI sigal to my monitor kept going off and on repeatedly. Eventually it would just say "No Signal" when windows would boot up.

So I tested vga from monitor to dvi on video card via adaptor and it worked fine. One week later I came back from a friends and my LCD was in sleep mode which was odd because I never have sleep mode on. Tried to wake it up with keys or mouse and would not. Turned it off and went to power on and LED wouldn't even turn on, just nothing, no power.

Looking online I have found multiple things that could be the problem but I really don't know much about displays. I found this forum which is awesome.

After some research I took apart my monitor to look at the power supply. Only thing that I knew what to look for is bulging/busted capacitors. The 35v capacitor is definitely bulging at the top and maybe even the really big one laying on its side, but none are busted.

Could really use some help here because I don't rally have the cash laying around for a new monitor. I am going to post pics in a few minutes in hopes that someone can see something I do not. Also it seems like the heatsink is directly connected to the psu covering most of the capacitors so it isn't easy to see.

[inaliz]

Re: Soyo 24" stopped, help!

As you can see in the pics the 35v is bulging for sure and then the bigger one looks to be also. There is also one behind the 35v under the shield that is bulging a bit. Do you think this is my problem?

[mockingbird]

Re: Soyo 24" stopped, help!

What a sad departure for Soyo, former champion of excellent motherboards, reduced to rebranding LCD screens.

I still remember that Soyo 6BA+ IV I bought off the Chinese kid at the coffee shop way back. What a superb motherboard.

Yea I've seen a 19" Soyo screen that was flickering purple every few seconds. I offered the owner to fix it, but he refused.

Me thinks you simply need to replace the capacitors. Desolder ALL the capacitors except for the smallest ones (Recording of course what went where), and then record the following information for each cap:

1) uF
2) Voltage
3) Width (in MM)
4) Height (If necessary - that is, you can be flexible with the height if their is physical leeway)
5) Pin diameter - the space in-between the two leads.

Some here will say I left out the series, but you'll have to ask here for suggestions as to which series to get, because your cheap capacitors probably don't have series information but the members here know what would suit you so just list everything here and you will be pointed in the right direction.

Good luck.

[inaliz]

Re: Soyo 24" stopped, help!

Thanks for the help, so it is most definitely those little bulging capacitors? I will do what you said although I haven't used a solder gun since I was 14 and I am now 27. Will have to go get a gun at radio shack, should I buy new capacitors at the same time or wait to post the info on each one?

Also I am guessing the small cylinder next to the power plug input, it is completely covered in rubber looks fine, should i cut th cover to check the fuse or would it be evident?

[mockingbird]

Re: Soyo 24" stopped, help!

I'm fairly certain, but you've got to replace ALL the capacitors even the ones that aren't bulging, because they might have already failed but simply not shown any signs of failure. This happens when they dry up inside.

No, don't buy the capacitors from radio shack, hell, don't even buy the solderer from radio shack. Go to the dollar store, get any cheap solderer, and then you can find a way to sharpen the tip to give you good accuracy. I ususally clip at it in a scraping motion with a pair of tinkerer-grade cutting pliers, but some people sand it. For the caps, post the values here like I said and someone here will tell you where to get them online.

You will also need flux and solder. I use the solder that came with the "cold heat" arch solderer I got on sale at Canadian Tire but has since bit the dust. If I can't find any solder, I use plumbing grade solder, but I will be yelled at for suggesting doing that here. For flux I use plumbing flux, and have never had a problem with it.

The cylinder leave that alone. I think it's called an induction coil. All it is in the inside of the protective cover is a thick coiled wire.

[PlainBill]

Re: Soyo 24" stopped, help!

This MAY be a difficult job. The ID10T who decided to put the caps under the heat sinks should have his hemorrhoids cauterized with a hot soldering iron. Maybe then he would be able to remove his head from his a**.

You may need two soldering irons; I'm not sure how difficult it is going to be to remove the heat sink. It's a safe bet that a 20 watt iron isn't going to work. You'll also have to unsolder all of the diodes and transistors attached to the heat sink; it doesn't look like you would be able to detach them. I'd suggest a product called Chip-quik to make the removal job easier.

Once you have the heat sinks off, get the information on every electrolytic cap, even those under 100 uF. Contrary to my usual advice, also replace the large capacitor (probably 120uF, 450 Volt) since that looks like it is bulging.

I highly recommend Digikey as a source of parts. They have high quality parts at good prices, and quick shipping. If you need assistance selecting parts, list the value, voltage, brand, series, height and diameter of the caps. The dimensions are important, you don't have a lot of clearance there.

PlainBill

[EGuevarae]

Re: Soyo 24" stopped, help!

The ID10T who decided to put the caps under the heat sinks should have his hemorrhoids cauterized with a hot soldering iron. Maybe then he would be able to remove his head from his a**.


PlainBill

[inaliz]

Re: Soyo 24" stopped, help!

Ok so I started on the project, I finally got the heatsink off which was no easy task they had it soldered in 5 different places each and then screwed to multiple other components which I had to unsolder because it was impossible to unscrew...

After that I examined every thing thoroughly and I wanted to show you a couple things before I continued. There are 2 parts on the board that have circular almost burn marks, I wanted to check and see if this could be the problem. There are 3 caps that are definitely bulged, 1000uf 35, 1000uf25,and a big 450v.

heres the pics.

you can see the burn mark on the right under the pink thing, upper right is where the other burn is on the other side.

another pic of the same

Bad picture it was very hard to get a good shot th small burnt area is around a little red component.

Let me know what you think if this doesn't seem likea problem I will continue to remove and list the caps.

[EGuevarae]

Re: Soyo 24" stopped, help!

The caps should be replaced entirely, especially under those conditions. As for the burnt component, it should be a diode (top), a resistor (bottom, red "thing") or both

[Krankshaft]

Re: Soyo 24" stopped, help!

Due to the circular darker char pattern I'd say the diode is what caused the discoloration. The resistor is too far off the board to have caused that.

This happens normally on cheaper PCBs due to heat exposure. But sometimes is a result of component overheating due to bad caps.

[mockingbird]

Re: Soyo 24" stopped, help!

Bulged samXons? Are those fake?

[PlainBill]

Re: Soyo 24" stopped, help!

Bulged samXons? Are those fake?

Not necessarily fake. Putting caps under a heatsink like this is much like putting them in an oven. VERY bad design.

PlainBill

[inaliz]

Re: Soyo 24" stopped, help!

Not necessarily fake. Putting caps under a heatsink like this is much like putting them in an oven. VERY bad design.

PlainBill

Also this monitor has been on heavy use since I got it april 2008. It has probably been off for less then 2 weeks total the entire time. I work from it and also a gamer.

In the process of removing and listing those caps will update asap, you guys rock!

[inaliz]

Re: Soyo 24" stopped, help!

So I have the time to work on my lcd today. I have removed the 3 bad caps, they were the 3 biggest ones underneath the heat shield. The rest of the caps on it look healthy. So should I replace these 3 or do I need to replace every cap on the entire psu? 17 in total including the tiny ones.

[PlainBill]

Re: Soyo 24" stopped, help!

So I have the time to work on my lcd today. I have removed the 3 bad caps, they were the 3 biggest ones underneath the heat shield. The rest of the caps on it look healthy. So should I replace these 3 or do I need to replace every cap on the entire psu? 17 in total including the tiny ones.

First of all, good job removing those heat sinks. I'd hate to have to do that. I'd really hate to have to do that twice.

I count 18 caps. See the attached pictures. Given the conditions those caps were working under, I have to ask this question: Would you prefer to replace all of them now, or replace three now and the rest in six months? Remember you will have to remove the heat sinks again if you have to replace the rest.

I am also concerned about the two overheated areas, in particular the one next to the large cap. That looks like it may have gotten hot enough to damage the component and weaken the solder on the underside of the board.

PlainBill

[inaliz]

Re: Soyo 24" stopped, help!

I am also concerned about the two overheated areas, in particular the one next to the large cap. That looks like it may have gotten hot enough to damage the component and weaken the solder on the underside of the board.

PlainBill

Yes these concern me as well but don't know what I am supposed to do about it. Those 3 caps are the only ones really crammed in a horrible place under the heatsink. I would like to try to replace those 3 and see if it at least works.

[PlainBill]

Re: Soyo 24" stopped, help!

Yes these concern me as well but don't know what I am supposed to do about it. Those 3 caps are the only ones really crammed in a horrible place under the heatsink. I would like to try to replace those 3 and see if it at least works.

Well, it pains me to say this, but that's not a totally bad idea. It would be a pain to have replaced all the caps then discover the monitor still doesn't work.

I do have an alternate suggestion, however. There are two areas that are discolored. You photographed the underside of the board for one of them - the one with less damage. Take a close look at the underside of the board for the other one. Does the solder look bad? Is the diode(?) shorted?

PlainBill

[inaliz]

Re: Soyo 24" stopped, help!

Underneath the mark you are talking about is just solder no diode and it does look rather bad compared to the rest.

[PlainBill]

Re: Soyo 24" stopped, help!

Underneath the mark you are talking about is just solder no diode and it does look rather bad compared to the rest.

The 'diode' I was referring to is the component on the top of the board. Notice how the discoloration is centered on it's leads?

PlainBill

[inaliz]

Re: Soyo 24" stopped, help!

Yes, underneath that is just solder I am saying.