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Capacitor replacement help needed: high pitch noise with new cap and dvd tray wont open?

I just wrote this question and i pressed cancel to cancel upload images and it deleted the entire question!!!! i will rewrite this breifly.

i replaced cap in dvd player and new one makes high pitch noise and dvd tray can't open. new cap was from old electronics, is it bad too?

written from ipod touch

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poiihy (author) 1 year ago

Update! I fixed the DVD Player!!! :D

I recently salvaged parts from a broken CRT TV and from that I got three 1000µF capacitors: one 16v and two 25v. These are nichicons! The original caps in the DVD player are "xunda" or something like that.

The original cap in the DVD player was 10v so I used the 16v cap.

After installing it, I tested it and it worked! At first the motors were weak when trying to open and close the tray but it quickly gained strength and now works fine.

But the hissing sound is still there. I found out where the hissing sound comes from. It does not come from the capacitor, it comes from that transformer next to it! I found that out by touching the components with a tool (being careful not to zap anything of course) and found that the sound changed when I touched the core of the transformer, and also some sound emitted from the tool. So the high pitch sound is from the core of the transformer vibrating! Perhaps it's loose and needs some hot snot to secure it?

poiihy (author)  poiihy1 year ago

Why can't I choose my own answer as the best answer? :P

poiihy (author) 2 years ago

here are he pictures.

UGH i hate mobile devices...

the replacement cap is the big one nearby the transformer.

the new cap is a 1000uF 25v and the old one is 1000uF 10v

1568822A-ECC5-451A-8CA2-77581A08FB5B.JPG1903A624-D690-4D85-A76D-81FDB01D13F8.JPG18D2DA4F-7BC8-45CC-836C-E3BD98885011.JPG

I know this thread is a year old but I figured I'll try to see if your problem was resolved because I appear to have the exact same issue?

Happiness: I recently acquired a Toshiba DVD Video Player SD-3390 (for free) which just happens to have the exact same power supply that you have in your picture. It has TAS0000019XX printed on the power supply circuit board.

Issue: The unit does not power on at all (no LED light when plugged in hence why it was free). However, it makes a very high pitched sort of hissing noise when plugged in with the cover removed. The source of the noise appears to be originating from the power supply somewhere near that yellow transformer (T901) if I put my ear close to it.

Potential Root Cause: That Xunda 1000uF 10V capacitor closest to the transformer (labeled C907 on the board) is nowhere near as bad as the one in your picture but it does appear to be bulging a little on top. See my picture. I'm guessing it's that capacitor that's the culprit?

Validate: Can someone confirm by ocular inspection if that is the case? How can I test the capacitor on the board to see if it is blown?

Recommended Resolution: Should I go ahead and replace this capacitor to see if it fixes it? Any gotchas or risks with trying this fix (I promise to use a brand new high quality cap)?

poiihy (author)  SquirrelMaster4 months ago

Wow cool; nice to see my discussion was helpful to someone.

To the best of my knowledge, any capacitor that bulges at all is bad and needs to be replaced. That bulging cap is likely the problem.

My DVD player is still working fine!

Attached pictures of the power supply board TAS0000091XX and the likely offending capacitor C907 circled in red. I'm not experienced with identifying blown capacitors. Can someone verify by seeing the pictures whether it is bad and needs to be replaced? If so should I try to de-solder the cap and solder a new one?

IMG_20170131_180051019.jpgIMG_20170131_180124073.jpgIMG_20170131_180139412.jpg
fmarquis2 years ago

Let us be systematic here.

First, I agree it was soldered using the right polarity as the first power on would have settled the issue.

Second, capacitance and voltage selection were appropriate.

Third, as electrolytic capacitor do not age well, replacing an old busted one by a possibly older one is not the best idea.

Fourth, the good question is : what is the purpose of this capacitor? So close to the transformer, it is probably there to filter the ripples. That means that when it blew, it is likely the microprocessor was feeded unregulated current and some damage could be the consequence. However, as microcontroller usually work or not, your "partial" functionality may indicate that a microcontroller or an IC dedicated to opening the tray is dead.

Fifth, a very very interesting question is why the capacitor blew? Voltage spike through the transformer? Check the resistance of the transformer and probe for continuity issues. A basic multimeter is the only thing you need. It will help you see if you have a solder bridge or if dirt and grease accumulated through the years shorted something.

And be careful, as if you try to measure you transformer while connected to main power you can fry everything, including you. Like dead... So don't measure while plugged in the wall please.

And btw, while increasing voltage rating won't affect the circuit, increasing the capacitance may, so stay around 20% more if you want to increase it.

If you want to try something quick, juste change the cap for a brand new one and make sure you don't have solder bridge.

Hope that helped you a little!

poiihy (author)  fmarquis2 years ago

Reply to your fourth question:

The "partial" functionality is not due to a blown IC, it's because the system is not receiving enough power. When a motor tries to turn, it jerks a bit but fails because the power supply cannot supply enough current.

But I do think the replacement cap is bad too, because I think it came from a pressure cooker circuit in which the beeper was weak and the relay did not work when I tested it.

I'll be on the hunt for caps.

fmarquis poiihy2 years ago
Yes, this is probably the best thing to do. When I started playing around with electronics,one of the first thing I did was to buy a pack of resistors, capacitors and potentiometers to cover the most usual values. Each bag of brand new components was only a few dollars. However, if this is the only device you plan to fix, this is not cost effective! Keeep me posted on your progress!

If only you had a way to test your replacement capacitor candidates... I mean besides using the DVD player itself as your Cinderella capacitor tester.

I mean supposing you had some way to test these capacitors, and some criteria for what is good capacitor, or what is bad capacitor, then this might speed up the process. Maybe.

Or maybe you could ask one of these internet forums for help. They've got people on these forums who are clairvoyant about electronic components. That way someone with clairvoyant vision could tell you about the capacitance, or series resistance, or parallel resistance, of your capacitors, without you having to probe them yourself

By the way, if this capacitor is being used for filtering, it probably won't hurt to use a replacement with equal or greater capacitance. If the original was 1000 uF, a replacement rated 2000 uF, or 10000 uF, would probably work too.

Also the voltage rating for the replacement capacitor, should be equal or greater. Also you need to get it placed in the right direction. It won't work if the polarity is backwards. Also the soldering has to be good, or else it won't actually be connected. I dunno. What else could go wrong?

Also BTW, I am wondering what prompted you to replace this particular capacitor in the first place? I mean, that's the mysterious part about this question.

poiihy (author)  Jack A Lopez2 years ago

In the first picture you can see the old cap. It is bulging and leaked a bit of electrolyte. The DVD player did not work at all, but after replacing the capacitor, it kinda works. I said this in my question the first time, but after I wrote my question I lost it so I didn't want to rewrite it all over again on the tiny iPod keyboard so I just wrote breifly.

I see it now. The loose capacitor, turned sideways, in that picture, the metal cross on its top is cracked open. So, yeah, I guess that cap was kind of crying out for help. Moreover, replacing it greatly improved the functioning of your player. So, good work! And congratulations on your progress so far!

I forgot to mention: You can wire two or three (or N) electrolytic capacitors in parallel to make, effectively, one big capacitor. For example, if you want to try a 2000 uF capacitor, but you don't have one of those in the junk box, you can wire two 1000 uF caps in parallel (or four 500 uF caps in parallel), and that will work. The only drawback is the soldered-together cluster of parallel capacitors might not fit neatly into the old footprint on the board.

poiihy (author)  Jack A Lopez2 years ago

Oh! Wiring capacitors in parallel! I forgot about that! I could do that...

This DVD player is huge and has a lot of wasted open space inside so there is plenty of space to stuff stuff in it.

poiihy (author)  Jack A Lopez2 years ago

It would be useful if I had a capacitor tester. I only have a lousy basic analogue meter from Home Depot that can only measure up to 200mA on its current meter (quite useless).

I'll just assume the replacement capacitor is bad too. I think this cap came from the power supply from a pressure cooker. When I tested that power supply the relay didn't work so maybe the cap is actually bad.

I'll be on the lookout for 1000uF caps and if I'll find one i'll put it in. If I don't find any others around then I'll have to get some from ebay.

Electrolytic capacitors degrade over time. Not really a good idea to use one from another device. If the system is making noise it may be due to issue with the new cap or harmonics coming off the transformer.

There is a chance the old cap blew to problems elsewhere in the system.

rickharris2 years ago

The voltage isn't an issue.

Is the cap in the right way round?

poiihy (author)  rickharris2 years ago

yes, otherwise it would explode!! LOL

i am not actually sure it is the cap making the noise; it could be a component nearby...

here is a video

http://tinypic.com/r/w1ag7b/8