Diode ID

[sound....@btconnect.com]

Hi,

I need to ID a diode. It is in the regulation circuit of an old 28v Power Supply.

http://wallyheider.com/wordpress/2014/08/the-birth-of-the-3m-m56-16-track-audio-recorder/

Markings are Z104 (twice) and CDC.

There are other diodes on the board in the 1N4001 case style/size, but this one is slightly longer and thinner and has a black shiny coating, not matt.



There is a schematic on the Interweb for this machine, but this supply does not correspond to that circuit.



Cheers,


Gareth.

[frank]

sound....@btconnect.com wrote:
> Hi,
>
> I need to ID a diode. It is in the regulation circuit of an old 28v
> Power Supply.
>
> http://wallyheider.com/wordpress/2014/08/the-birth-of-the-3m-m56-16-track-audio-recorder/
>
> Markings are Z104 (twice) and CDC.
>
> There are other diodes on the board in the 1N4001 case style/size,
> but this one is slightly longer and thinner and has a black shiny coating,
> not matt.

the Z in the marking might indicate a zener diode. Is the original part
dead? If so, your best bet is to reverse-engineer the schematic so to
guess better what is the right substitution.
A power supply shouldn't be that hard to fix.

HTH
Frank

[JC]

The old Lambda power supplies used a FBM-Z104 6.2V Reference diode.
Make sense?

[sound....@btconnect.com]

That makes perfect sense.
This is a Lambda supply, the diode is almost certainly a Zener.

Thanks very much!


Gareth.

[sound....@btconnect.com]

On Thursday, January 12, 2017 at 2:20:12 PM UTC, JC wrote:

Supply still not working with new 6.2v zener.
Do you know of any schematics for this? The PCB is Lambda HAL-01-006.



Cheers,


Gareth.

[sound....@btconnect.com]

Oops, I'm an eejit, there are 2 Remote Sense connections on the PSU output that are required to be connected, the PSU is now running fine.


Cheers,


Gareth.

[pf...@aol.com]

On Thursday, January 12, 2017 at 11:03:03 AM UTC-5, sound....@btconnect.com wrote:

> Supply still not working with new 6.2v zener.
> Do you know of any schematics for this? The PCB is Lambda HAL-01-006.

First, a possible source for help would be:

http://www.us.tdk-lambda.com/hp/service.htm

Then, it has been my experience that when the Zener goes, it is only after much else has gone. Test _ALL_ the diodes (they are cheap enough anyway), and _ALL_ the caps.

Without delving any deeper, is this a solid-state supply? If so, I would be checking the VR chips throughout.

Peter Wieck
Melrose Park, PA

[Gareth Magennis]

wrote in message
news:4974db18-5c56-48f8...@googlegroups.com...

This PSU is all discrete, the only problem was the Zener, fortunately.
There is a fair amount of circuitry here.



Thanks to all who replied,


Gareth.