Component (Diode?) Identification

Hi team. This is my first post on this forum.
Hoping somebody may be able to assist with some electronics knowledge.
Ive managed to blow up the frequency generator output of my HP8903 Audio analyzer. (I think a high voltage surge on something I was testing has made it into the output)
This is where I have tracked the issue down to. I have blown a “SM1”125mA fuse on the Output attenuator board and directly after the fuse I have found 3 diodes which are shorted. I just need some help Identifying the black one (one leg lifted) in the picture. As can be seen the silkscreen shows it as a diode. It has a “F” printed on the body, and “033”
The light blue diode has printed on it “1N47” “33A”
Also unable to track down a replacement SM1 fuse if any one has any clues for me that would be much appreciated.
Thanks!!

black one is not clearly visible... we need to see label on that diode...

It's clearly marked on the PCB as a zener diode, and I'd assume a 33V one as it says 33A on it.

The black one could be anything, do you have a schematic?.

Nigel Goodwin said:

It's clearly marked on the PCB as a zener diode, and I'd assume a 33V one as it says 33A on it.

The black one could be anything, do you have a schematic?.

Click to expand...

Thanks. The Black one is marked not as a Zener but a regular Diode. The Light Blue one appears to be the Zener?

No Schematic for this PCB. Just Block diagrams in the service manual

MacIntoshCZ said:

black one is not clearly visible... we need to see label on that diode...

Click to expand...

Sorry I shouldve pointed out.. The Black Diode says 033 as visible from the identical one visible in the pic below it.

Im guessing the Blue one is a 1N4733A?
The Black diode is the tricky one for me..
I guess I can measure the good one beside it which might give some clues?

'Generally' a diode is a diode, it would be very rare if it was critical - just stick what you have in and see what happens.

Nigel Goodwin said:

just stick what you have in and see what happens.

Click to expand...

=)

MacIntoshCZ said:

=)

Click to expand...

Like I said, a diode is a diode

Considering the existing one is S/C a 1N4001 has got to be better, or even a 1N4148.

the black diodes are likely pretty close to a 1N914 or 1N4148. they may be painted black for a reason, as in some high gain circuits, a diode can act as a photodetector, and generate current from ambient light. but considering it's a piece of HP equipment there's also the fact that they do also sell test equipment to the military, so they use mil spec components in most of their gear, and all glass diodes in mil spec gear are painted...

a 1N4733 is a 5.1V zener and rather common in the US. since there's not enough room lengthwise, they often split the part number and print it as:
1N
47
33A

here's a data sheet for the 1N47xx series of zener diodes...