ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi all,
Finally got round to replacing the IR capacitors in my Beolink 7000 which has the 'no contact' problem. It was my first attempt at doing anything on this level and I was sure to proceed methodically and slowly referring to the several helpful threads on the forum. It took me 5 hours but I managed everything ok, although the surface mounted capacitors were very tricky to say the least!
I replaced the lithium battery at the same time but stopped short of replacing the backlight as that was probably a bit too adventurous (although I did have the parts from Conrad!).
Frustratingly now everything is back together i'm getting exactly the same problem as before. The BL7000 is working but only in one way mode - I've removed and added the components again in the system menu but still no joy.
Now assuming I've completed the recap successfully (big assumption I know!) is there anything else that could cause this issue?
I don't have any other two way system to check the BL7000 with so can't rule out the Beomaster 7000 itself.
I know the obvious conclusion is that I've not replaced the caps correctly but wanted to at lease rule out any configuration settings I may have missed!
Any suggestions greatly appreciated!
Hi.
Did you clean the board? The acid moves under the chips...
I use alcohol and paint thinner to clean up.
Some guidelines are wrong. Some people do not read dots... 22uf is wrong, 0.22uf is right. ;)
I have changed caps in 6 BL7000's and used these 22uF caps on all of them..
http://www.conradelektronik.dk/Elektrolytkondensator-Samwha-SC1C226M04005VR-SMD-22-%B5F-16-V-20-%25-1-ST.htm?websale8=conrad-dk&pi=421509&ci=SHOP_AREA_17428_0245812
I have had 1 where it didn't work after changing caps, and the only thing that helped on that one, was actually to remove the IC next to the 2 caps, and clean the board with alcohol. The leak was very bad, so I guess there was a short under the chip.
Otherwise, you might need to re-check your SMD soldering, they can be very tricky if you haven't done it before.
/Weebyx
Some have 0.22uF, others have 22uF.I'm not sure if one value is a factory mistake but I've seen both and bothseem to work (obviously - or the units wouldn't have passed factory testing and inspection).There's also a couple of other caps in there, that needs attention too.Martin
In the service manual for the lc2, the schematic for the ir receiver says 22 uF, and all the components and schematic is the same in the bl7000, and 5000 in fact also..
So maybe 0.22 is a factory mistake as you mention ?
/weebyx
Mistake? No.
Take a 22uF 6,3V SMD cap and compare the size to a 0,220uf cap.
The size is complete different and would not fit on the board, much to big.
There are circuit plans showing correct 0,22uf and others (like LC2) show 22uf
But 22uf works, and 0,22 also. I have had both and worked.
Thanks for all the replies - a lot of helpful advice in there!
@Die_Bogener -
I used 99.9% isopropyl alcohol to clean the board after removing the old components but not after installing the new ones - is it best practice to do this?
@Weebyx -
I used the 22µF caps that you linked to on Conrad - I ordered 6 of them in case I bodged it so have a few left over spare. Yes, the SMDs were a real pain - with the other components around them I belt a bit impeded in how I could position them and being able to see if they'd made sufficient contact with the pads. Removing the metal box round the SMDs was a hassle as well - what is it's purpose? Is it vital so get it all soldered back on afterwards?
@Lee -
Brilliant advice! I used the front facing camera on my phone and could see the IR emitter on the BM7000 periodically flashing so can pretty much rule out that it is the cause of the issue.
@DIllen / Weebyx / Die_Bogener
I've used the 22µF 6.3V SMD cap which appear to be the same value that was on the board initially and also replaced the 6.8 µF 63V and the two 4.7 µF 50V on that board. (I used the list from this thread http://archivedforum2.beoworld.org/forums/p/3595/35443.aspx )
Some additional information that may help - when I press the volume up/down buttons on the BL7000 the backlit display goes blank with every press before reappearing (the display remains lit just the play ff/rw buttons etc vanish for a split second). Is this normal behaviour?
I guess the weak link in the chain is most likely me and my SMD soldering - but for a first time attempt at least I didn't make the BL7000 any worse!
Isopropyl is very good for cleaning up before soldering.
Cleaning after soldering is technicly not necessary... but it looks better. I like it clean and hate it when somebody can see somebody was working on.
These are 0.22uF/63V in a Beolink 7000http://archivedforum2.beoworld.org/cfs-filesystemfile.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.78.06.BL7000+Repair/IC.pngThey are the same size as 22uF/6.3V which seems to be most common.Even 10V and 16V versions are the same size:http://i01.i.aliimg.com/wsphoto/v0/783597267_1/20pcs-16V-22uF-SMD-Electrolytic-Capacitor-22UF-16V.jpgMartin
Dillen: These are 0.22uF/63V in a Beolink 7000http://archivedforum2.beoworld.org/cfs-filesystemfile.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.78.06.BL7000+Repair/IC.pngThey are the same size as 22uF/6.3V which seems to be most common.Even 10V and 16V versions are the same size:http://i01.i.aliimg.com/wsphoto/v0/783597267_1/20pcs-16V-22uF-SMD-Electrolytic-Capacitor-22UF-16V.jpgMartin
The first picture is actually the one where I had to remove the IC before it worked :) Forgot I put it up here....
Hmm, so I guess that we should use 0.22 ? The one I buy from Conrad (22uF) are also the same size as the original..
But why are they .22uF in Beolink 7000 and 22uF in the LC2 schematic ? the IC and circuit are the same in the IR receiver part ?
It was probably never foreseen that there are some crazy people repairing them after 30 years...
... these parts were never planned for repair, just for swapping complete boards.
In the 80-90ies it was unknown that these SMD caps are the worst crap on this planet for electronics... some people thought everything would become better with SMD. Reality is harder...