The Workbench

Re: Beocord 9000/8000 VUs and Belts

Dillen — Wed, 14 Nov 2007 15:49:36 GMT

Derek,

You have a PM regarding repair of the VU display.

Martin

Re: Beocord 9000/8000 VUs and Belts

auric — Tue, 16 Oct 2007 19:58:37 GMT

Very interesting! Its almost like surgery; the equipment is beyond my means.

I am curious about how you remove the old LEDs from the display?

Re: Beocord 9000/8000 VUs and Belts

Dillen — Tue, 16 Oct 2007 15:28:21 GMT

Reaching a technique for doing the display rebuild took me
a couple of years but there is no secrets.

It's basically a matter of doing SMD work, contact-free soldering using hot air under a microscope.

The LED's are microtiny ½x1mm (0402) or about the size of this punctuation mark.
The LED's are normally only used in production and usually comes in production-rolls holding typically 2.000, 5.000 or 20.000 pieces.

For hot air soldering, I've tried different ways and brands.
I don't recall the brand I have at present but it was in the EUR 1400 range.
A vacuum holding tweezer device is used for handling the tiny SMD LED's
and soldering is done using solder paste (refrigerator storage!) from a dispenser running at pressurized air together with the vacuum tweezers.

The microscope is a fairly standard 20x/40x as you would use
for biological experiments in petridiscs but converted to lift
high enough to fit and focus on a display on a holding device underneath or, in some cases, a whole board.

Gloves, glue, tools and chemicals for clearing off the old junctions etc.
Furthermore, a Metcal soldering iron with a custom-made tip is used if a final touchup is needed.

Everything (including the workshop area) is antistatic to protect the electronics.

PM for info regarding belts.

Martin

Re: Beocord 9000/8000 VUs and Belts

auric — Tue, 16 Oct 2007 14:45:46 GMT

Hi Martin:

What's the procedure for replacing the elements in the LEDs? Aren't all of the elements epoxyed in?

Where can the VU bars be gotten? Any ideas how much for a belt kit?

Derek

Re: Beocord 9000/8000 VUs and Belts

Dillen — Tue, 16 Oct 2007 14:04:48 GMT

Belts are available as a set.
Idlers are, as far as I know, not available new but in most cases
a good cleaning, lubrication and fresh belts will get the Beocord going again.

The 4-digit display can be repaired but it's a bit costly
because of the hours and special tools etc. that are needed.
Repaired segments will be much brighter than old ones so all
segments will have to be replaced.
I've seen faulty VU meter displays too but it's much rarer and so
far good used replacements could be found.

Martin

Beocord 9000/8000 VUs and Belts

auric — Tue, 16 Oct 2007 12:23:26 GMT

Hi:

I have a Beocord 8000 and 9000 both with a dead led segment on the VU as well as a dead segment on the counter led.

Has anyone figured out how to repair these? They seem to use exotic elements.

The VU LEDs is an entire module; one that I've never seen before a standard bargraph element.

Also is there a belt/idler kit available?

Thanks,

Derek