"Scott Vance via groups.io" <scott_l_vance@...> writes:
In the process of fixing 9 pcs E5071C, I have noted that at least
three of them have low output power on both channels
(-26 dBm on two, -31 dBm on the third). I confirmed that the faulty
component was the Vernier Leveler and then took this
apart to take a look. It seems like it's always the expensive
components that burn out, so I decided to remove IGC1-4213
and bridge the contacts on either side of the component. Sure enough,
the output power went up from -26 dBm to about -9
dBm. Some limited information about this part is available on the
Keysight. Looks like it's a 11 dB gain power
amplifier, so the numbers check out and it looks like this is the
failed component. Assuming that they drive it at 9
dBm gain, that would give me the right power at my port (0 dBm
nominally).
Replacements components appear to be hard to find and expensive
(around $500), which is a pretty good indication that
failures on this component are common place. The Keysight page
indicates that they sell parts (1GC1-8213) in lots of 10
pcs, so I've put in an inquiry.
My questions:
1) Is it possible to get a IGC1-4213 data sheet?
2) There are some similar component numbers (IGC1-4214, IGC1-8213).
How does one tell which components are compatible
and which are not? Data sheets seem to be unavailable and every time
I ask Keysight a question they respond that they're
happy to fix it for me, just send them a check for 6K USD.
3) Of the 9 units, there are two components that have failed and
knocked out about 6 of the units. In other words, two
failure mechanisms keep repeating themselves. Keysight has got to
know this. Why don't they have a service bulletin or
something? Why don't they offer a reasonable repair service for these
components which appear to have been designed to
fail? Just a rant I suppose, but I'm not too impressed. On the plus
side, it makes my job easier because once I figure
out the failure I just have to apply the same solution over and over
again.
Did you make any progress on this?
I just finished fixing the mainboard issue on my E5071C. Measured the
output power on the Ports when set to 0dBm and all have around -23dBm
level. So looks to me like my E5071C has the same issue. The only
thing that i find odd is that bridging two ports shows a straight
S12/S21 line at 0dB. I would expect it to be around -20dB. How is that
on your units?
Thanks
Sven
