EEVblog #1243 - Sony Boombox REPAIR and Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: September 03, 2019, 01:09:54 am
content: Repair and teardown of a Sony CFD-V10 portable stereo boombox

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 03, 2019, 01:50:51 am
content: What are the chances of opening the subscription feed to find a Sony-related video with the view counter on a number that reminds me of the PS3 Linux fiasco?

author: Towger
author_rank: Super Contributor
timestamp: September 03, 2019, 02:03:37 am
content: Quote from: NiHaoMike on September 03, 2019, 01:50:51 amIt no surprise most of your feed is for female makers

author: johnlsenchak
author_rank: Frequent Contributor
timestamp: September 03, 2019, 02:13:06 am
content: Awesome video Dave, all we needed at the end was for you to hold that Sony boom box over your head while playing the song "In your eyes"Service Manual ( If you are playing along at home)https://elektrotanya.com/sony_cfd-v10_sm.pdf/download.html#dl

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 03, 2019, 03:01:45 am
content: Quote from: Towger on September 03, 2019, 02:03:37 amAt 14 girls (Anne of All Trades, April Wilkerson, Becky Stern, Blitz City DIY, Blondihacks, Jennelle Eliana, Kim Tippin, Laura Kampf, LE3D, Naomi Wu, Nerdphilia, Rachel Metz, Robohemian, STEMinine) and 13 guys (AvE, Big Clive, Brian Lough, Defpom, EEVblog, Electronoobs, Great Scott, Joe Smith, Julian Ilett, mjlorton, OpenTechLab, Thomas Sanladerer, VoltLog) visible on the screenshot, that's pretty close to a 50/50 split. Add one more girl (Freelee the Banana Girl) and one more guy (Going Off Grid) if you want to count the bottom row that got cut off.

author: Towger
author_rank: Super Contributor
timestamp: September 03, 2019, 05:19:51 am
content: Easier on the eyes than Defpom in a vest.

author: ggchab
author_rank: Frequent Contributor
timestamp: September 03, 2019, 07:18:43 am
content: Interesting repair videoHow easy was it to correctly realign the button with the needle and gear on the PCB to get correct readings on the display?

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 03, 2019, 12:48:42 pm
content: Quote from: ggchab on September 03, 2019, 07:18:43 amI would guess just turn both to one end, then it will be at most a notch off.

author: ggchab
author_rank: Frequent Contributor
timestamp: September 03, 2019, 04:02:48 pm
content: Maybe. Just wondering.Always "funny" having to remove all screws again when you discover that the needle stops in the middle of the displayThis kind of stories happened to me several times...

author: tszaboo
author_rank: Super Contributor
timestamp: September 03, 2019, 04:46:13 pm
content: I hope you realize what you just did... Few years from now, you are opening your mailbag, and there still going to be a few mixtapes in the packages.

author: SeanB
author_rank: Super Contributor
timestamp: September 03, 2019, 07:39:47 pm
content: Saw that SIP package on the dodgy heatsink, and, aside from diodes on the power board, the transformer pins being dry jointed and that SIP package has the only thing holding it to the board being a single screw at one end ( applied after the wave soldering) and knew that one or more of those pins are dry. Mostly because the holes are larger than you expect from the lead dimensions.Then off to the QC team, who plugged it in to a chassis jig, and aligned it, after doing the visual inspection and adding of "production line enhancements" to the board. Then off to assembly, where, because Sony wanted them to need almost no after assembly adjustment, they probably worked perfectly on test.Got an Aiwa unit of similar function, made around 1988, and it still is in use daily, though sadly the LCD displays have started to darken from age, the CD player requires yet another KSS210 laser assembly, and while it is only 11 pounds on eBay, I actually have not listened to a CD in years. Tape deck ( the fancy dual deck with high speed dubbing) the same, all the rubber parts and a good number of plastic bits are broken, so it is a very nice FM radio now, with a built in clock and the ability to have timed turn on.When the CD player actually worked, in the 1990's, I used it to wake to music, so wanted the CD player to start playing on power on, which it did not do. So, added one CD4016 CMOS analogue switch, and a few cascaded RC circuits, to simply wait 10 seconds after power on, and emulate pressing play for a half second. Fitted on a bit of Veroboard 8 strips by 6 holes, and used what I could find around, lots of Vishay wet tantalums and similar (never seen them again, but have a box of mixed ones) dry rectangular tantalum capacitors, which used colour dots for value and voltage on the black surface, like old style mica capacitors and resistors, and polarity was marked by the one lead being gold, and the other being silver.

author: open loop
author_rank: Regular Contributor
timestamp: September 03, 2019, 08:23:52 pm
content: So rather than the mix tape (as cool as that is) and asuming the tape mech is dead how about a mod to add Blutooth Audio usig the tape audio path, obviosuly the BT module will put way more signal than the tape heads but it may work?? Would be a good mod I think.

author: ChunkyPastaSauce
author_rank: Unknown
timestamp: September 04, 2019, 02:31:00 am
content: The sticker at the back of the case allows the main case to be injected molded cheaply. If it were just solid (no sticker with no hole in the case) then the woofer port bridge would form an undercut; you'd have to use a slider in the mold, secondary operation, or some other technique to finish the port for a lot more than the cost of a heavy sticker.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 04, 2019, 12:52:47 pm
content: So, what's the correct way to design a product so the solder joints do not fail like this around hot parts?Is the problem that the heat sink is screwed down hard to the circuit board, so thermal expansion/contraction is always a "fight" between the solder joints and the screws?

author: nctnico
author_rank: Super Contributor
timestamp: September 04, 2019, 03:45:37 pm
content: Quote from: SilverSolder on September 04, 2019, 12:52:47 pmYes. It is a very common failure mode. I've seen it many times myself.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 04, 2019, 11:12:09 pm
content: Quote from: SilverSolder on September 04, 2019, 12:52:47 pmUse a spring to press the parts to the heatsink. Also possible is to bend the leads to prevent them from pulling on the solder joints.

author: BillyD
author_rank: Regular Contributor
timestamp: September 05, 2019, 07:33:29 am
content: Just wondering if there was any particular reason for sucking out the old solder and replacing it with new?Is it better in some way than just reflowing?If it was lead-free solder, personally I'd replace it with leaded solder for a repair, but I don't imagine this was lead free.I suppose it would also be helpful to beef up the amount of solder material there as well.

author: thm_w
author_rank: Super Contributor
timestamp: September 05, 2019, 08:40:00 pm
content: Quote from: BillyD on September 05, 2019, 07:33:29 amSo if you just reflow (with flux) you might still be left with whatever corrosion/dirt was in the original joint. Its also not "known good" solder, compared to a roll you have on hand.If you add new solder to old, you could end up with an alloy that does not have desirable properties.https://www.eevblog.com/forum/beginners/mixing-lead-solder-with-lead-free-solder/http://www.circuitinsight.com/programs/50659.htmlBut for any sort of home repair these are not big concerns.

author: EEVblog
author_rank: Unknown
timestamp: September 07, 2019, 11:37:37 am
content: Quote from: BillyD on September 05, 2019, 07:33:29 amYes, reflowing does not add new flux to clean the joint.And if you add more fresh solder (with flux) it just adds too much solder to the joint.Most professional solution is to suck off and put new solder.

author: EEVblog
author_rank: Unknown
timestamp: September 07, 2019, 11:39:28 am
content: Quote from: SilverSolder on September 04, 2019, 12:52:47 pmYou can use bent lead parts, so then thermal strain does not affect the joint as much.Nt uncommon in large power diodes for example to add a thermal "loop" in the lead at each end to take the street off the die and solder joint.