Megaworks 210D Integrated Sub amplifier repair

[ljbrandt]

Greetings all!

I am an owner of a 8y/o Cambridge Soundworks computer speaker set (Megaworks 210D). Just recently, both satellite speakers and the sub have starting making an irritating buzzing sound. I have ruled out ground loop by disconnecting all inputs except the power cord and also tired various outlets in my house, yet the buzzing remains. Oddly though, sometimes the buzzing is very loud and at other time is barely noticeable.

Doing my due diligence, I did some research and found that the culprit may be bad capacitors and/or zeners. CSW wants $75 PLUS round-trip shipping to repair the amp. My question is, is there anyone who would be willing to walk me through a repair given pictures of the amp board? I am quite teachable and would be willing to post a movie on youtube for others' reference.

[seanc]

Re: Integrated Sub amplifier repair

The first thing we're going to ask you to do is open it up and take good clear pictures. Start with pictures of the power boards in the sub - unless you know they're somewhere else.

Attach them using the manage attachments options.

[ljbrandt]

Re: Integrated Sub amplifier repair

I know it's been awhile since I made this post, but I finally got around to taking the pictures of the power board inside the sub. Let me know what to do next, thanks!

[ljbrandt]

Re: Integrated Sub amplifier repair

I should also mention the buzz heard in the speakers is loudest when the speakers are first powered and then slowly subside a bit when the unit 'warms up'. Hope this helps too.

[ipman]

Re: Integrated Sub amplifier repair

I see one of the big filtering caps bulging. Can't read the value in your images.
Remove it and measure capacity and ESR if you can.

[ljbrandt]

Re: Integrated Sub amplifier repair

Does 220 uF / 200 V mean anything? I've never taken a capacitor off of a PCB...may have to look up how to's on youtube.

[seanc]

Re: Integrated Sub amplifier repair

Have you any experience with soldering?
If not do some Youtube searches...

220uf is the capacitance, 200v is the voltage the cap can handle.
Width and height also need to be factored in when looking for replacements.
I would replace the pair.

[ljbrandt]

Re: Integrated Sub amplifier repair

Have you any experience with soldering?
If not do some Youtube searches...

220uf is the capacitance, 200v is the voltage the cap can handle.
Width and height also need to be factored in when looking for replacements.
I would replace the pair.

Thanks for the reply Seanc!

Saw some good videos on youtube and I think I'm ready. Just need to order some replacement caps.

two questions:
1. Do I need the 'snap-in' type or the radial type
2. Which of these three would be best? All meet the size and # requirements (taken of newark.com). Is the ESR, the manufacturer or capacity life the most important factor when choosing a replacement?

http://www.newark.com/jsp/search/bro...3D422%2B201222

Thanks!

[seanc]

Re: Integrated Sub amplifier repair

Snap-in and choose the Panasonic if it will fit.

[ljbrandt]

Re: Integrated Sub amplifier repair

Is it alright if the Panasonic is not a snap-in type?

[seanc]

Re: Integrated Sub amplifier repair

Despite what Newark says, the ECOS2DA221BA is snap-in. Look at the datasheet, also I've bought the TS-HA series before so I know they are.

[ljbrandt]

Re: Integrated Sub amplifier repair

Awesome...I'll put in the order and report back after the installation is complete!

Thank you for your help!

[momaka]

Re: Integrated Sub amplifier repair

If you haven't ordered the caps yet, get a 63v, 470uF cap as well. There's one like that on your board and its quality looks rather questionable (as do the other smaller caps as well, but those usually don't endure that much stress so they don't need to be replaced). The power supply in your amp is an SMPS, so for the 63v, 470uF cap, any of these caps would be a good replacement:
Panasonic - FC, FR, and FM
United Chemicon - LXY, LXZ, KY, and KZE
Nichicon - PM, PW, HE, and HD
Rubycon - YXG, ZL

[ljbrandt]

Re: Integrated Sub amplifier repair

Unfortunately, I have already ordered the 220uf 200v power filter caps. I did notice the 3rd cap, but didn't think to order it :-(. I may give the power filter cap replacements a try 1st and see if that works and then order the 63v 470uf later. One follow-up question though, I noticed a brownish substance between the large caps and the board...is this some type of adhesive to counter-act the vibration in the sub? If so, do you think this may cause difficulties in trying to remove the old caps...and would I need to use a similar adhesive paste when installing the new caps? Thanks in advance!

[seanc]

Re: Integrated Sub amplifier repair

Yes it's adhesive, which you should find is nice and crispy and will break easily.
Don't bother replacing it.

[ljbrandt]

Re: Integrated Sub amplifier repair

SUCCESS! Sounds just as good as the day it was new! Actually, I forgot just how good this 2.1 system really sounds :-) All from only replacing the two power filters caps - funny that I didn't even know what they were called.

I'm not sure the purpose of the 63v 470uF cap is, but I'll just let it ride for now since everything seems to be working. One thing I did find alarming though was that the brown "L" shaped metal piece just above the power filter caps seem to get VERY warm just from a short period of testing. I'm hoping this is normal for that part as I have no idea what it does.

Complete newbie, first time soldering, EVER much less messing with caps...but low and behold, a $2.99 soldering iron, $1.99 lead-free solder and a few youtube videos did the trick! Saved me at least $75 from having to send it in to Cambridge Soundworks.

Seanc, momaka & ipman - thank you so much for your help! If you guys ever happen to be in Montgomery, AL let me know and I'll buy you a beer!

Here are some pics of the result - notice the top left solder joint gave me some issues...the solder just didn't want to adhere to the base of the joint and I ended up having to redo it a few times (used my vacuum cleaner to suck off the old solder). Not pretty, but I hope it holds..only time will tell. Thanks again guys!
Solder joints on new caps (not super pretty)


Messing around with repairing a broken microphone cord


Cheap Harbor Freight soldering iron...tip already broken


The old caps

[scoutii304]

Re: Integrated Sub amplifier repair

I just did the same repair and it worked like a charm. Under $15 and my Megaworks are back in business! I know this is a year-old thread, but I want to thank jlbrandt for posting, and also seanc and all the rest for the how-to. Thanks!

[willzone1]

Re: Integrated Sub amplifier repair

I just tried this fix, and it didn't work for me
Thanks to everyone here for their ideas, you gave my MegaWorks hope!
(P.S. As a professional electrical engineer, I'm certain that this wasn't a "user error" on the fix, and that something else is broken in my amp...)

[fmichael]

Re: Integrated Sub amplifier repair

Hello All
I wanted to register and post here because I googled this exact problem with my 210D and found this thread. I repaired the subwoofer as described above and was successful in repairing this unit. I have a few of these units and have over the years returned them back to CSW for the 75.00 repair with shipping each time. After recent contact with CSW, they are no longer servicing this unit, or selling new ones for that matter.
The 2 caps online were 20.00 delivered(bought 4) and basic soldering did the trick.

I would gladly donate to this forum monetarily as I am sure it cost something to maintain a bulletin board and keep it up and running. I do not see anywhere a donation can be made.

Perhaps this next issue should be a new thread, but I wanted to throw it out there if anyone else might have had this other issue with the 210D. I have had to also send other units back to CSW because of blown fuses. I know this unit says on for long periods of time and will sleep during times when there is no signal to the amp. When I have replaced the fuse in the past, it would blow as soon as the power was turned back on. It was a 75.00 repair at CSW, the same as the hum issue. I wondered if anyone had any ideas, or fixes in mind for something like this.

Again. I very much appreciated everyones help. Saved alot of time and money.

[willzone1]

Re: Integrated Sub amplifier repair

Thanks fmichael for stirring the pot here, forgot to post the outcome of my 210D. Unfortunately, although my unit had the same symptoms as above, the issue with my unit was with some corrosion of the circuit board. The vibration-damping glue the manufacturer used to hold one of the caps onto the board ate through a few layers of board and tracing. The resulting corroded pit seemed pretty irrecoverable, so it rests in peace in my basement. Satellites are still good though, so I've got that going for me, which is nice...