Pink single lead of a 8594e power supply unknown

[herculeseev]

Hi guys,

iam trying to repair a 8594e agilent/ HP

That analyzer has a problem in its if section, because all rbw above 30khz not working. They only give a flat high response, without any signs of the connected generator signal.
Below and above 30khz rbw the signal appears to be ok.
I suspect one of the rbw boards (A11 or A13) might be faulty. Trying to follow the service manual. Next step injection of 21.4 MHz to A15J8 Pin22.

Since the signals with small rbw are ok, the rf frontend should be healthy.

Now i need to feature out which rbw board is responsible for which rbw setting. Any hints are welcome and appreciated.. 😄

But first of all I am confuse about a pink single cable which comes from the power supply. There is also a jack with 5 or 6 leads coming from the supply which are connected to a board. But that pink line has its own jack and its not connected, and i can't discover where it belongs to.

Measuring result was exactly 0 Volts, and the service manual gives me no hint.

Any ideas how it should plugged in? On other pictures i can see that it disappears betweens the power supply enclosure and CRT enclosure towards Mainboard.

Regards
Thomas

[MarkL]

...
But first of all I am confuse about a pink single cable which comes from the power supply. There is also a jack with 5 or 6 leads coming from the supply which are connected to a board. But that pink line has its own jack and its not connected, and i can't discover where it belongs to.

Measuring result was exactly 0 Volts, and the service manual gives me no hint.

Any ideas how it should plugged in? On other pictures i can see that it disappears betweens the power supply enclosure and CRT enclosure towards Mainboard.

Do you mean W51 coming out of the right-hand side of the power supply?

If we're talking about the same thing, the wire is violet on my 8595E and it has a 3pin housing on the end which is not connected to anything.  According to the Assembly-Level Repair Manual, it supplies -24V to the A7 analog control board on 8592L and 8593E analyzers.  (I believe it's used to extend the YIG tuning range for those models.)

A photo would be helpful.

On the BW problem, note that the BW5 signal is correlated to your problem.  Table 5-1 (pg. 260) shows it should be at +14.0V for BW >= 0.1MHz and at -1.0V for BW <= 30kHz where you report it as working.  That could be a clue.

But then you also say "Below and above 30khz rbw the signal appears to be ok.".  Which is it?