SMT capacitor value?!! - Page 1
Forum section: electronics / beginners

author: kasumyku
author_rank: Regular Contributor
timestamp: July 30, 2017, 06:14:09 pm
content: Hello,Can anyone help me figure out the value of C259 capacitor, it's a SMT type with no markings, on the schematic it says .1zX.I've searched all over the internet and couldn't find much.Cheers!!

author: wraper
author_rank: Unknown
timestamp: July 30, 2017, 06:18:31 pm
content: should be 0.1uf

author: kasumyku
author_rank: Regular Contributor
timestamp: July 30, 2017, 06:23:21 pm
content: Thank you for your reply, any idea what zX stands for?I would need to get some and I'm not sure what to order.

author: wraper
author_rank: Unknown
timestamp: July 30, 2017, 06:31:25 pm
content: dunno what that means for sure. Probably shortened code for ceramic type, voltage rating. Just get 0.1uf X7R of X5R with 25V or better 50V rating an you'll be safe. It does not matter much anyway. You could put 47n or 1uf cap there and it would not make any difference.

author: kasumyku
author_rank: Regular Contributor
timestamp: July 30, 2017, 06:33:46 pm
content: Much appreciated for your help!!

author: Kjelt
author_rank: Super Contributor
timestamp: July 30, 2017, 07:36:37 pm
content: Quote from: wraper on July 30, 2017, 06:31:25 pmUnless you can see the pcb layout and know for sure, it could well be that this cap is placed very near that opamp to decouple its supply and that the 10u is placed much further away, so I would stick with the 100nF minimum to be safe.

author: wraper
author_rank: Unknown
timestamp: July 30, 2017, 10:49:27 pm
content: Quote from: Kjelt on July 30, 2017, 07:36:37 pmIt was not recommendation, just example for it not being critical. 47n vs 100n for opamp decoupling won't make any difference. 100n is there only for a reason of industry habit using particularly 100n nominal. Of course if it was some critical high frequency stuff, there might be a difference, but then multiple different (thousands of times) value ceramic capacitors are used in parallel.

author: Zero999
author_rank: Super Contributor
timestamp: July 31, 2017, 12:02:09 pm
content: What does the circuit do? What's the part number for the op-amp?Again, not a recommendation but that 100nF capacitor might not even be necessary, especially if the circuit doesn't have any fast switching or high frequency components. The capacitor was probably put there because it's good design practise. Unless it's an extremely cost sensitive design, it's much more cost effective just have an excessive number of decoupling capacitors. They do no harm and it's better to have too many, than too few as insufficient supply decoupling can cause problems, which will be expensive to debug and fix later on.

author: kasumyku
author_rank: Regular Contributor
timestamp: August 01, 2017, 11:17:12 pm
content: Its from CS Sub10 powered subwoofer preamp board.Op-amp part # NJM2060MI just added 2 new pics: 1st its the full schematic, 2nd has notes regarding the caps.p.s.: Already ordered .1uf 50V (1206 X7R).Thank you!

author: Zero999
author_rank: Super Contributor
timestamp: August 02, 2017, 05:53:20 pm
content: Quote from: kasumyku on August 01, 2017, 11:17:12 pmThat's a fine choice.

author: Greg W
author_rank: Newbie
timestamp: February 15, 2021, 04:02:25 pm
content: Hi, I have problem identifying the dead capacitor for the Boston Acoustics CS Sub10 Power subwoofer Power circuit board. The Capacitor on the attached circuit board drawing is C11 (CD473X) . See detail on the attached drawing. Could someone help me the specification of the capacitor I need to purchase and website that i can order it from. Really appreciate the help in advance !

author: wraper
author_rank: Unknown
timestamp: February 15, 2021, 05:02:38 pm
content: Quote from: Greg W on February 15, 2021, 04:02:25 pmShould be 47nF ceramic capacitor. But why wouldn't you just read marking on capacitor? And why do you want to replace it to begin with?

author: Greg W
author_rank: Newbie
timestamp: February 15, 2021, 08:59:21 pm
content: Hi Wraper,Thanks for your quick response and assistance. Just want to give you background of my problem. I have a Boston Acoustics CS Sub10 powered subwoofer for over 7 years. Recently I noticed NO sound coming from the subwoofer. The power mode switch is at the back of the subwoofer. I probably have the power switch on the ON mode instead of AUTO DETECT mode. So it is probably ON for couple months and burn out the preamplifier or power transformer circuit board of the subwoofer.I am just a beginner and try to learn on the fly. I have no testing equipment or meter to do any testing. I have been using “EYE BALL” and common logic to do diagnostics of the issue. I did the following test steps :1 I used a 9 volt battery to connect to the lead of subwoofer to verify the speaker is in working condition.2 The LED light on the Power mode switch is in GREEN when I connect power to the unit. So there is power to the unit.3. I check the power transformer and no sign of bugging on the coil or heat damage.4. Eye ball checking of the capacitors and connectors on the Preamplifier circuit board and NO sign of heat damage. I have attached pictures of the two circuit boards for your reference.5 Volume switch on the preamplifier looks fine and turns OK.6. Eye ball checking of the capacitors of the power adapter board. The only sign of heat damage is on capacitor C11 as discussed on the previous thread. The manufacturer has put glue on capacitor so the marking is no too visible. I have attached picture of the capacitor C11. The marking on the capacitor is faintly marked 220. Since I am a beginner, I have no idea whether the picture of C11 is a ceramic capacitor or not. Could you verify that for me. The documentation of the electric drawing for C11 show value of (CD473X) which you said is 47n or 1uf cap. But if it is a 47n cap, then the marking should be 475. Is that correct?I also check on the internet and could not found marking of 220. The closest marking is 221 or 223.Also do you come across another common problem on the two circuit boards for Boston Acoustics CS Sub 10 subwoofer. Any other suggestion I should check?Thanks,Greg

author: wraper
author_rank: Unknown
timestamp: February 15, 2021, 09:18:29 pm
content: It's not capacitor but 22uH inductor.

author: tooki
author_rank: Super Contributor
timestamp: February 15, 2021, 09:26:47 pm
content: Quote from: Greg W on February 15, 2021, 08:59:21 pmAs wraper said, the component you desoldered is an inductor. Right above C11 in the schematic is L03, which is specified as 22µH, the same as the inductor you desoldered. And you can see the symbol for an inductor in the component silkscreen on the board.Quote from: Greg W on February 15, 2021, 08:59:21 pmNo. The last digit means the number of zeros to append. In the case of ceramic caps, that's in picofarads.47nF = 47000pF => 473 (47 followed by 3 zeros: 47 000)475 would be 4700000pf = 4700nF = 4.7µF

author: Greg W
author_rank: Newbie
timestamp: February 15, 2021, 09:50:39 pm
content: Hi Guys and Gays,Thanks for all your reply and assistance. I found this on EBay :10pcs Magnetic Core 22uH Radial Leads 6x8 6mm x 8mm Inductors.Is that what I need for the replacement Inductor ? See attached picture.Any other US or Canada web site that has faster delivery of 22uH inductor ? Ebay purchase is from China and delivery is 30 - 50days.Any other suggestion of other potential areas I should check for my NO SOUND CS Sub10 subwoofer beside the inductor ?

author: tooki
author_rank: Super Contributor
timestamp: February 15, 2021, 10:49:33 pm
content: Quote from: Greg W on February 15, 2021, 09:50:39 pmOK, so you've addressed me twice (since I'm a gay guy), but what about the women on the forum?Anyhow, what makes you think the original inductor has gone bad?!? It looks fine to me.Quote from: Greg W on February 15, 2021, 08:59:21 pmElectrons are invisible to the naked eye, so in electronics, test equipment is absolutely essential. Of course, visual inspection is a key part of diagnostics and repair, but cannot tell you everything — not even close.Rather than ordering components, you should order yourself a multimeter first, and I'd also suggest one of the $15 component testers from eBay/AliExpress that let you put in almost any basic component (resistor, capacitor, inductor, transistor, etc, but not ICs) and it'll tell you what it is and give you basic measurements.

author: wraper
author_rank: Unknown
timestamp: February 15, 2021, 10:56:36 pm
content: Quote from: tooki on February 15, 2021, 10:49:33 pmNo longer has one of its legs after brutal removal. It can be fixed though. I wonder why it was even removed to begin with, it's not like this inductor could cause amplifier not working.

author: tooki
author_rank: Super Contributor
timestamp: February 15, 2021, 11:03:58 pm
content: Quote from: wraper on February 15, 2021, 10:56:36 pmD'oh! I missed the missing leg! So it probablywasfine until it was removed.

author: Greg W
author_rank: Newbie
timestamp: February 16, 2021, 09:19:01 pm
content: Hi Gentlemen and Ladies,My Bad on pulling the inductor off the board. I able to solder the inductor back on to the board. Any suggestion what I should look at next ?I have attached the board diagram and circuit diagram of the Preamplifier and power board of the Boston Acoustics CS Sub10 subwoofer for you reference.Thanks,Greg

author: Zero999
author_rank: Super Contributor
timestamp: February 19, 2021, 09:07:36 am
content: Start with the power supply.Test all the fuses.Where does ACL and ACH come from, presumably a big transformer? Does it look good? Perform a continuity test on the primary and secondary windings.Next is D12 and D13: do all the diodes work?