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
Soren
That's not a problem, I still have a lot of work to do elsewhere on this exercise...I'm still awaiting delivery of some components to complete the recap and replacement of the trimmers....I have however managed to complete the final cuts on the side panels for the case, the veneer is currently being flattened and softened prior to gluing in place, all takes time ;¬)
Craig
Does anybody know what size the screw is that holds the rubber feet to the base of a BM4400 ?
I inadvertently tossed away the badly corroded screws when I removed the damaged/missing original feet, they are very small self tapping screws, the manual just describes them as rubber feet.
Walnut burr strips are flattening nicely, it's taken a while to get them completely flat and they look a little pale right now.
As I'm still awaiting delivery of parts, getting a little annoying now, I had noticed that the stereo lamp wasn't coming on when selecting the FM function, I had purchased a replacement 3IC1 as a precaution during the last tuner episode that I undertook recently, turned out to be nothing more than the tuning lamps, however what turned up was a LM1310 with a note from Little Diode advising me that this was an equivalent for a MC1310.
So I replaced the suspect device with little diodes offering and it didn't work.....to make sure I was on the right track I removed the 3IC1 from my basket case 4400 and installed it in place of the LM1310 and everything worked just fine, stereo lamp comes on and off as stations are tuned in, tuning lamps don't work though...surprise surprise. The pin out of these two devices don't look massively different, though they clearly are...or could this just be a faulty LM1310 supplied by little diode?
The only difference I can spot in those application notes, is the small capacitor from pin 3 to ground.You could try that, but I would expect the two ICs to be direct replacements - only from two different producers.
Martin
according to this RCA-Datasheet of an CA1310 they should all be the same...
hx
Well this only leaves two possibility's...one I soldered the chip in badly, or two the chip I fitted was defective. In either event the solution I have opted for is to replace the LM1310 with a RCA-CA1310A, as described above, from Langrex (5 pieces for £5) and I'm going to replace the variable capacitor too for good measure.
Early stages of sanding and finishing the side panels
I love the veneer - you are rapidly becoming the repair expert in the UK!
Peter
That's very encouraging Peter, thank you.....but lets not loose site of the fact that everything I do is made possible only with the guidance I receive from the more knowledgeable members of this site ;~)
Replaced the dodgy IC and also fitted a new variable capacitor to the Basket case stereo decoder.....ended up with 4 spares of each due to min order numbers......but they were very cheap it has to be said, so if anyone is in need let me know.
Graig,
If I can share a little bit of my recent experience, please do yourself a favour and change all 6 jumpers from the IF board to the tuner box. I was done with my project and found that FM was no longer working just before closing the hood. The jumpers tested good at both ends but all the way open or high resistance when measured from the inside of the tuner box to the solder points of the IF board. Four out of six were holding by the wire sleeve only... Common problem apparently...
Completed the work on the bottom plate, new feet.
And the pre amp board....
Pretty much done with the sides of the case now........top is taking a bit more time.
Recap complete....replaced burnt out lamp in the radicator and repaired a broken wire between the tuning lamps, now functioning fine.
And the casing is coming along nicely.
Well done Graig!
I never did veneer capping, how hard it is? Do you have to remove the old veneer first?
Nice work on the veneer. I see you used Titebond veneer glue. Did you use a vacuum press or did you use a flat board and clamps?
Applying veneer isn't particularly difficult actually.....one needs to soften and flatten the veneer first, lots of info and videos on the internet about this, and also about the gluing and finishing procedures. I researched applying veneer on top of existing veneer and seemingly as long as the existing veneer is still in good condition and firmly attached there should be no problems....I've done this twice with fairly good results. As for the gluing I cold press the veneer to the substrate (the board your gluing it to) and leave it for 24hrs.
Well.....this is as far as I can go, still short a power switch and of course the preset cover, Martin....got any left?
To be honest I'm not too sure about this colour.
However given its condition when received I'm quite pleased with it, sounds spectacular, as one would expect, also.
Very nice. Excellent work. I can't say I am a fan of the veneer color but you did a fantastic job with rebuilding the case. The nice thing is you could always make another set of cabinet panels now that you know how to do it. I think I would choose rosewood veneer just because that is my personal favorite. I enjoyed your thread. Keep up the good work.
-sonavor
Agree with Sonavor, I will get to the switch this evening, sorry but didnt have a chance before. As luck will my son is visiting from Denmark next week, if the switch is OK he can bring it (or whole assembly) back to DK and ship from there
Collecting Vintage B&O is not a hobby, its a lifestyle.
Soren.....that's very good of you, please let me know how much you want for it and I will arrange for payment.
Regards Craig
Bad news, opened the BM 4400 yesterday evening, went straight to the switch to check it with my meter, but got funny readings, when switching on-off the ohm jumped while switching but in both positions showed mega ohms. I left it there until today and took out the switch
I cleaned the switch and worked it some 50 times but it still didnt work, cleaned again and worked it, and at last the switch blade came out
Here close up
Here where it came from
And here what it looked like when I finished. I dont recommend changing this switch if avoidable, its a big PIB to change it.
Thanks a lot Soren for the pictures.
Confirms to me that the switch needs an spark killer capacitors and explains why this common failure.
Soren my friend.....that's a massive amount of work you undertook on my behalf, I don't know what to say.........I really appreciate you doing this. And I have to say looking at where you got to and what it took to get there I can only agree with your advice not to try and change this switch. Even changing the whole assembly would be an exercise in itself.... I will reconsider the position over a glass of wine, I suggest you join me after all you have done
I done it before, back in 2012 i think,
Yes.....I remember reading your post detailing that total strip down, your a hero to take it on a second time .
Ok fortified by the glass of wine that Soren should have drank I removed the back and had another look, note the missing solder tab bottom right that came apart when the wire was unsoldered.....I stupidly lost it, thinking the switch is totally wrecked anyway.
When testing for continuity across the two left hand side connectors I noticed I had good contact when the central slider was stopped from moving completely into the bottom position, the picture shows the switch in the OFF position, when in the ON position the slider is at the bottom of its slot.
Ever optimistic I have fashioned a new solder tab from an old relay base and have epoxy glued it into place.
I know it all looks a little "Heath Robinson" but when in Rome, and with wine
And with a small wedge of plastic epoxy'd in place....
If it works, looks doesnt matter, only you and I will know
Soren....I dont know what to say, tested the switch out with a multimeter and both poles are working fine.....I'm not confident such a repair will last the test of time but for now it looks good.
Power switch OFF
Power switch ON.......I feel so guilty for putting Soren to so much trouble and then fixing the switch myself, however long it lasts I feel I should have tried harder before agreeing to let someone spend so much time....sorry Soren