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
and now the emitter of transistor 151......looks suspect
Had a good go at this today and pulled transistor 151.....however it tested out fine, but I replaced him anyway just to be sure.
Next I went after capacitor 152....he was also good, but I replaced him too
following on I went after the capacitor on the base...….this one
However when I threatened it with the soldering iron I noticed both legs where actually soldered together on the board, shorting them out in effect....this pic was taken after I cleaned off the excess solder and separated the two points, I am going to blame this on soldering in components with the board in the vertical plane encouraging the solder to flow down
Encoraged by this find I hooked up the sig gen and scope once more......
And was rewarded with this reading at the emitter of transistor 151...…..
confident I had located the issue I went on to hook up the good doctors Thornes once again and ow both channels sound excellent once again.....happily this concludes the component replacement exercise......
I recognize that Alan Parson record! Good work Craig.
Are you going to replace the rusty DIN sockets?
Jacques
Your right of course....I like a bit of Alan Parson, as for the DIN sockets I hadn't planned on drilling out the rivets to remove them, I will have a go with the Dremel to remove as much oxidation as I can then take stock. Meanwhile I have spent a bit of time looking at the condition of the cursers, I have new lens provided by Martin but still need to do something with the lens holder.....they are quite yellow with age.
I have tried soaking one in sterilizing fluid overnight, the lens holder is much improved....but when compared with one of Martins replacements the lens is still quite opaque...….
Spent a little time on the damaged corners of the pre-amp/tone control board.....super glued the broken bits in place then gave them a liberal covering of epoxy resin.....
I'm optimistic that they will hold for some time....
And just for a change of pace did a little mindless sanding on the top, removed the old varnish....there are one or two dings that are too deep to sand out and will bave to be lived with. Bees wax and a good polish will finish it off.
Craig,
What's the temperature set point of your soldering pen?
I didnt know Frede provided cabinet parts too......as for my soldering iron, its not an expensive one so i'm not confident about the accuracy of the temperature setting but Ihave it around 450 degC.......
Craig
Which is definitely too much. I always use 370 Celsius.
chartz: Which is definitely too much. I always use 370 Celsius.
I use 350°C for soldering and up to 380°C for desoldering only on very big solder points (not on PCBs) I go higher
Collecting Vintage B&O is not a hobby, its a lifestyle.
Fair enough....I have wound my temperature setting to 350°C......thanks for those words of wisdom ;¬)
At Jacques suggestion I have had a look at the DIN connectors...I don't think the condition warrants drilling out the rivets just yet......
And from the outside.....
I'm thinking a bit more of a clean up inside, particularly around the RCA connectors should be fine.....had a look at the panel complete with Martins lens.....lens holders came up good and once all assembled they look like new.
Nice to see things coming together.
-sonavor
Craig: I'm thinking a bit more of a clean up inside, particularly around the RCA connectors should be fine.....had a look at the panel complete with Martins lens.....lens holders came up good and once all assembled they look like new.
So beautiful when it’s new—which it is, isn’t it?
Well.....look what turned up in the post today!
And nestled inside was the lens donated by Charles, much appreciated as these are quite a rare animal....I owe you one my friend ;¬)
Hi Craig who is Frede and what service does he offer?
Hi Steve
Frede Kristensen is a legend in these circles....he is Classic Audio, other members will know a lot more about him than I. He provides services and guidance to members of this forum and has a wealth of knowledge from his years as a B&O design engineer, I don't know the full extent of his services but I'm sure others can advise you.
Next step is to remove the remains of the damaged lens from my panel....
Little help from the Dremel removed the stubborn fragments at the bottom...
And there he is.....in his new home.
Finished article......these are such a delight
Job well done! Congrats
Vähintään yhdeksänkymmentä prosenttia suomalainen!
Great result!Now on to the next!
Martin
Steve_hayes8310: Hi Craig who is Frede and what service does he offer?
Link to his website: https://www.classic-audio.dk/
I'm glad it made the travel safely!
You owe me nothing other than keeping me entertained with your future projects!
Congrats!