Took apart my Tektronix DPO4034

[allanw]

a

[GeoffS]

And the important question - did it still works when you put it back together? 

[alm]

Thanks for the pics. Maybe the moisture sealant is to keep leakage low, so it lasts longer on the lithium cell?

[saturation]

Awesome, and brave! of you.  Thanks for sharing.

[allanw]

b

[alm]

I wonder what the chips marked 7SB42 D9DCG are? There are 8 on my scope, but there's enough lands for 16. This must be the ADC's, because the DPO4000 series goes from 2.5GS/s sampling to 5.0GS/s.

No hits on Google from the marking on the chip.

It sounds plausible that they're the ADC's, and in that case, it's quite likely that it's custom silicon. No manufacturer uses off-the-shelf ADC's, except in the very low end. This is part of what makes the faster scopes so expensive.

[mikeselectricstuff]

And what are these missing modules?
There's a total of 12 of them, in groups of four, scattered around the top of the board. Maybe it's for the MSO models with 16 digital lines?

I think these may be connectors for a high-speed logic analyser connection and/or MICTOR connectors - they appear to be grouped in differential pairs.

As regards the moisture sealant, this will be to avoid leakage due to board contamination on the RTC crystal's high impedance connections.

On the same subject, here are a couple of pics indide my Agilent MSO6034A :

[saturation]

Wow.  For comparison, compare those boards to the Rigol 1052E, the integration and parts density of your scopes are intense.

From Dave's photos:

[Mechatrommer]

whats the zigzag traces on mike's scope/pic? there are 2 big on the middle right (1st pic), middle left on the 2nd pic? looks funny.
ps: 3 last pics in the 1st post are broken. or isit just me?

[jahonen]

And what are these missing modules?
There's a total of 12 of them, in groups of four, scattered around the top of the board. Maybe it's for the MSO models with 16 digital lines?

I think these may be connectors for a high-speed logic analyser connection and/or MICTOR connectors - they appear to be grouped in differential pairs.

As regards the moisture sealant, this will be to avoid leakage due to board contamination on the RTC crystal's high impedance connections.

On the same subject, here are a couple of pics indide my Agilent MSO6034A :

Great, now I don't have to open mine. I like those high-speed length matched differential pairs Kind of amazing how both the Tek DPO4000 and Agilent MSO6000 have similar large lithium battery.

shafri: The zigzag is for length matching, to equalize the propagation delays on the PCB. A common high-speed technique.

Regards,
Janne

[Mechatrommer]

hmm ok thanx. the heatsinks tell the story, not the usual rigol thing.

[scopeman]

Thanks for the pics. Maybe the moisture sealant is to keep leakage low, so it lasts longer on the lithium cell?

The moisture sealant area is to keep moisture and humidity from affecting the RTC and crystal for the time of day clock. Even a pF or so can change the frequency of the oscillator or cause it to stop.

Scopeman

[tinhead]

I wonder what the chips marked 7SB42 D9DCG are? There are 8 on my scope, but there's enough lands for 16. This must be the ADC's, because the DPO4000 series goes from 2.5GS/s sampling to 5.0GS/s.

There's a total of 12 of them, in groups of four, scattered around the top of the board. Maybe it's for the MSO models with 16 digital lines?

my theory : probably only "bank memory" chips, for 5GSs you will need second one "big" custom BGA soldered between these two Tek custom chip (without heatsink), so in principle two 2.5GSs ADCs,
each with 10M sample memory but together still "only" 10M memory but 5GSs.