Identifying capacitors -- need help!  :) - Page 1
Forum section: electronics / repair

author: godfrey
author_rank: Contributor
timestamp: January 29, 2015, 08:26:37 am
content: Hello capacitor geeks!I am repairing an HP Designjet 4200 42" scanner. After multiple through hole capacitors failed on the power supply board and this thing has over 30,000 hours powered on -- I figured I'd just replace all the capacitors on the boards. It does currently function, but there's no telling how long that'll last...I need help identifying these SMD caps. I know each manufacturer has their own coding scheme -- so I'm at a loss.Every cap has values like;47CHB2U6241226E3306A1N8100JHB2U5But I'm at a loss as to what's what. Attached are some images of the caps. Could someone explain what these mean?Thank you in advance,Phil

author: DmitryL
author_rank: Regular Contributor
timestamp: January 29, 2015, 11:06:54 am
content: ... let me google for you... "smd electrolytic capacitor"

author: Kjelt
author_rank: Super Contributor
timestamp: January 29, 2015, 11:43:28 am
content: Quote from: godfrey on January 29, 2015, 08:26:37 amYou have to find the correct manufacturer and series to be sure about the meaning.This depends on the manufacturer and an example is given below for the Panasonic HB series electrolytes.Usually:First value is the capacitance in uF'sSecond are the Voltage rating and the series of the manufacturerSo you have to google or try farnell/mouser etc. to find the correct manufacturer and download the datasheet, try HB series electrolytes for instance.PS: to get less sarcastic answers as the one above you better post in the "beginners" section of this forum

author: Wh1sper
author_rank: Regular Contributor
timestamp: January 29, 2015, 11:44:19 am
content: If it works, let it in peace.smd CAPs unsoldering and soldering is a lot of work, many caveats are there.Chances are high that these capacictors are working for another 30,000 hours.In Powersupplies are more heavy environment disturbance, so to say. at the PCB in photo it seams they are all PS bocking Caps so leave them alone until you have trouble

author: godfrey
author_rank: Contributor
timestamp: January 30, 2015, 07:35:20 am
content: Thanks for the replies. I have determined these are Panasonic brand capacitors. As far as replacing them, it's super easy for me. Just twist, grab the leads off the board with your iron and resolder. I used to work at a broadcast repair company with three other techs -- one guy averages about 50,000 of these a year because they go bad so often when equipment has high hours.

author: Evil Lurker
author_rank: Regular Contributor
timestamp: January 30, 2015, 08:27:48 am
content: If they are pannies I second the motion of leaving them alone. Panasonic IMO probably makes the best electrolytic capacitors on the market today, with perhaps Nichicon running a close second. Getting SMD electrolytic chip capacitors off can be a real pain sometimes and I would not want to risk lifting a pad or damaging a trace on some sort of logic/controller board that is still functional. PSU output filter caps on the other hand, yeah I'd say they might need to go.

author: Wh1sper
author_rank: Regular Contributor
timestamp: January 30, 2015, 08:29:14 am
content: Quote from: godfrey on January 30, 2015, 07:35:20 amOhh

author: godfrey
author_rank: Contributor
timestamp: January 30, 2015, 08:33:06 am
content: The value does not match the actual checked value of the capacitor out of circuit. Low ESR on many of them when tested with an ESR meter.Fortunately, there are only 45 caps in total…unlike the hundreds that are in Panasonic DVCPRO and Sony DV editing decks.