Agilent 33220A Generator, FPGA not repairable

[Andy Watson]

Thanks, I'll keep that in mind. I was looking for the exact part number. I will have to study the datasheets

[Quarlo Klobrigney]

The replacement part still would have to be programmed and where is that file? I wouldn't necessarily condemn the part until it is verified as bad.  The first thing I do is to reflow (resolder) all the stuff in the area especially if it is lead free. You'd be suprised how many faults can be repaired in that way. Nothing like a nice dull joint when you're done if using lead free or shiny for us leaded folks. That chip could be easily drag soldered in under a minute or so.

Thanks, I'll keep that in mind. I was looking for the exact part number. I will have to study the datasheets

[Andy Watson]

The replacement part still would have to be programmed and where is that file?

I believe that, as is often the case with FPGAs, the "programme" is loaded from an external device. The datasheet says:
"APEX 20K devices are configured at system power-up with data stored in an Altera serial configuration device [I think that means serial EEPROM] or provided by a system controller."
The 33220A appears to use the latter option, i.e. the programme is supplied via the system processor every time the unit is powered-up. I assume the programme is in the firmware of the system processor. 

[AF6LJ]

The replacement part still would have to be programmed and where is that file?

I believe that, as is often the case with FPGAs, the "programme" is loaded from an external device. The datasheet says:
"APEX 20K devices are configured at system power-up with data stored in an Altera serial configuration device [I think that means serial EEPROM] or provided by a system controller."
The 33220A appears to use the latter option, i.e. the programme is supplied via the system processor every time the unit is powered-up. I assume the programme is in the firmware of the system processor.

Now that makes a gob and a bunch of sense; stock one part, usit in twenty different products, Just add firmware.....
Makes its own sauce.


Like two way radio equipment of the late 80s a dozen models would use the same logic board, only the firmware, and a zero ohm resistor or two would change.

[Quarlo Klobrigney]

I was speaking in terms of a replacement device in a refit of the original, i.e. the new part number pin for pin or one on a daughter board to replace the unobtainium part.
Sorry for the confoosion.

[Andy Watson]

Ah, I see. That would be a tricky problem! However, if substituting a different part is the only option my first line of attack would be to use the FPGA that is in the current revision of the PCB.  HP/Agilent provide two versions of firmware updates for these devices - I'm guessing these corresponds to the two different FPGAs. I've not determined what other modifications might be necessary.

[Quarlo Klobrigney]

Well in your case (I haven't looked) they still provide support for it. Your very lucky.

They've orphaned my HP spectrum analyser for the sake of emailing or providing a link to the ROM files to which I can do up the EPROMs myself.
I will be forever stuck at revision x instead of the latest on their last run for the 8591A.
Also Dave is out in left field for that piece of equipment that he gave up on for lack of a service manual etc.

[HighVoltage]

I believe there are some more hardware differences.
The change was made from the MY43... to MY44... serial numbers and the later one should have been called 33220B but somehow that was missed, I guess.

I was looking for the option board for the 10 MHz input /output and noticed that there are two different boards, depending on the serial before or after MY44...
More interesting, the option board for the earlier models can be ordered from a distributor as an option but the same board for the later one is not sold through distribution, but instead a "repair" part from Keysight directly.

So, it is probably more that just the FPGA