help with identifying an IC in Tektronix AWG2020 arb generator

[analogRF]

Long story short, I am in the middle of repairing an AWG2020 arb generator I got very cheap on ebay. I have restored a lot of things (all SMD electrolytics leaking all over the boards, PCB traces, pads, and the dead ADC chip) but I now have error 630 which according to TeK support guy means "5 X mag DA offset adjust fail". I know for sure (tested multiple times) that the big wideband CFA op-amp CLC561AI is dead. I am planning to replace it with a THS3001 or THS3091. I will install it on a small adapter board and connect the pins by wires and change the feedback resistors to have the same 20dB gain and 50 ohm I/O impedance like the original amp.

But that amplifier is only switched into the signal path (ahead of the attenuators) for amplitudes larger than 500mVpp. Below this amplitude that op-amp is completely cut off from the signal path by two relays. So I dont know if that is related to the error 630 or not.
However, I have two more suspects one of which I cannot even identify what it is. One is an 8 pin SOIC marked 842 (there are two of them. I suspect the lower one which has -15V supply) By the looks of it and the circuitry around it, I am pretty sure it is a UPC842 dual op-amp. It definitely looks like a chip by NEC. It is not in the signal path and certainly it does something else (perhaps used in auto calibration of amplitude or offset).

The other suspect is another 8 pin SOIC marked as CL404A. There are 2 of them on the analog board. I cannot find out what it is. I have looked everywhere and there is no information about this IC. I don't think it's custom made. It has no tektronix number on it and seems to be from a third party. Anybody has any idea what this IC is?

thanks

[tautech]

Find the Tek part # from the manuals and cross ref it here:
http://www.sphere.bc.ca/test/tekequiv.html

If it's not in that short list check the link at the bottom right of this page.
(Sphere ask for it not be linked online.  )

[analogRF]

Find the Tek part # from the manuals and cross ref it here:
http://www.sphere.bc.ca/test/tekequiv.html

If it's not in that short list check the link at the bottom right of this page.
(Sphere ask for it not be linked online.  )

there is no tek P/N. The ic is marked CL404A and the manual does not have  a parts list.

[tautech]

Find the Tek part # from the manuals and cross ref it here:
http://www.sphere.bc.ca/test/tekequiv.html

If it's not in that short list check the link at the bottom right of this page.
(Sphere ask for it not be linked online.  )

there is no tek P/N. The ic is marked CL404A and the manual does not have  a parts list.

Bugger !
That won't make things simple. A quick look online indicates these have a tie up with Sony. Did they release an equivalent model ?
Seems everyone's looking for a schematic.

[analogRF]

I don't know about the Sony but, yes, I badly needed the schematics and I even contacted Tektronix but he simply said "these were repaired on board level and there is no schematics!"
Anyways, I have played around with that analog board A2 for many hours and I have a good understanding of the signal path but still there is so much I don't know specially how exactly the calibration of amplitude and offset takes place. There are 3 DACs and an ADC on board.

Anyways, that CL404A has been bugging me for the whole time....no idea what it is. It is not a dual opamp or at least not one with a regular pinout. because the circuitry around it does not correspond to popular pin connection of dual opamps...

[nctnico]

Better post a picture. Maybe there are other markings on the package. In some cases it is not clear what is the device number and date/manufacturer code.

[analogRF]

here is a picture.  There is also a JE215 below the CL404A but I could not find any thing on that either

now that we are at it, can someone please tell me what exactly are those elements I marked from 1 to 6
and how I can read their values? I think they are resistors but what kind? #4 has a dot on it, too, like a diode but it measures like a resistor in circuit.

[Neomys Sapiens]

Find the Tek part # from the manuals and cross ref it here:
http://www.sphere.bc.ca/test/tekequiv.html

If it's not in that short list check the link at the bottom right of this page.
(Sphere ask for it not be linked online.  )

there is no tek P/N. The ic is marked CL404A and the manual does not have  a parts list.

Are you sure that it is not a CLC404 respectively version thereof?

[nctnico]

A CLC404A seems to match the pinning.
The other parts may be laser trimmed resistors.

[analogRF]

but as you see in the picture, it is CL404A.
Since the high speed high output op-amp on the unit was CLC561IA from comlinear, it kinda makes sense that this one is CLC404
I will go with that in my troubleshooting to see how it turns out...

thank you guys.