Nice troubleshooting! Generally, I resolder EVERY joint on all the PCB's on any vintage machine I get in for restoration - time consuming, but well worth it!

Nice scope! Definitely among those considered for my Wishlist.

The vast majority of vintage B&O lamps are 25mA or 30mA - you can't go wrong if you choose a rating like that.

Menahem

Thanks for that... it seems as if 6V 30ma are available from my sources, so i'll try that.

I think I may have some ultrabright white LED's that I could try first though, then I don't have to worry about failure. Anybody upgraded with LED's before?

Yeah, the scope is quite a nice one... my late 70's Gould recently expired, so I treated myself to this LeCroy. I could either have a new no name Chinese 20MHz analogue scope, or this used high end digital scope for less money.

In this post, I dealt with the issue of changing to LED's, of which I am a fan, where possible.

http://forum.beoworld.org/forums/t/12646.aspx

That particular lamp on the sensor arm, I did not change, because it is relatively easy to change (do not need to dismantle the whole turntable) after a burn-out, which is relatively rare, and more importantly, the angle of the bulb is important to get the right concentration of light for the reflecting surface, so an LED, which is highly directional, may not be suitable.

But we're always willing to hear differently from you, if you succeed. I'd try a 3mm LED, instead of the regular 5mm units. Check the voltages - you will probably need a dropping resistor.

Menahem

Not only is the position of the lamps filament with regards to the lens system and the amount of light
output important. The type of light also needs to be right since the sensor is neither a photocell,
LDR nor photo-transistor but rather a voltaic cell.
A LED will not output enough energy to activate the system (at least they did not about five years ago when I
tried it) and LED's do not produce a continuos output but are switched on a high frequency.
As mentioned, I also tried the LED conversion but didn't manage to reach a working solution so I stick with lamps.
I have suitable lamps in stock if you cannot get one locally.

Martin

Right again, Martin :-)

Well it turns out that an LED will work!

Installed a 5mm ultra bright led yesterday, and the electronics side of the deck all work great.

The 5mm LED was very tight to fit, I had to shave down the flange at the end, so there was a flat on both sides of the LED, but it works great.

Anyway, another problem:

When playing a disc that is warped slightly, the arm doesn't follow the disc up and down - the cantelever of the stylus is! Luckily, i'm not using a decent cartridge or disc so far.

There is a thin brass coloured shaft, which it appears that the arm balances upon. I tried lubricating this with a sewing machine type oil, but i'm not sure which part of the shaft to lubricate - the end opposite the tracking force adjustment, or directly under the arm? Could the spring to do with the force adjustment have something to do with the problem?

Finally, what do people use instead of tool 3624009 for making sure the arms are tracking correctly?