Used Analog vs New Digital Scope

[DaveC]

Why not put a heatsink on the chip now to prevent or delay it from
dying in the future?

See my post elsewhere in the electronics NGs about doing exactly that.

 

[mike]

Interestingly, although your page claims that the 155-0241-02 variation
of U800 is more durable than previous ones (presumably 155-0241-01), a
Google News search shows about the same number of posts from users
asking about both part numbers. I wonder if the production quantities
were similar?

It would be interesting to correlate instrument serial numbers with chip
failures.
From what I hear, the -01 chip was unreliable. They redesigned it and
rolled the instrument serial number base for the -02 version. They
built a bunch of those.

Then some bean counter decided to sell the IC facility to MAXIM.
Somehow, about the same time, the instrument serial number base got
rolled again.
MAXTEK still produced the -02 chip but lost the recipe and started
producing unreliable chips again. I understand that the IC
unreliability problems were not restricted to just this chip.

According to my sources, there's a serial number range in the middle
where the chip reliability is much improved. I'll revise the webpage to
make that more clear.

Mine's in that middle serial number range. Just sittin' on the shelf
waiting for someone to come along and get a great scope.
mike

From what I can tell based on the service manual, this chip really isn't
anything all that special. It looks like an ordinary RPTV video driver
chip could replace it, if you made provision for the variable-gain
feature needed for the X10 magnification feature. There is plenty of
room under the motherboard for an aftermarket kludge^h^h^h^h^h^h
assembly, if anyone were inclined to develop one.

I just sold a 2467 on eBay with the -01 part number with 27,000 hours on
it, still going strong. My own 2467 has over 12,000 hours on a -02
part. So they definitely don't ALL die an early death.

-- jm

--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts Test Equipment
Honda CB-125S
TEK Sampling Sweep Plugin and RM564
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[Jim Yanik]

It would be interesting to correlate instrument serial numbers with
chip failures.

I'd also check date codes on the IC's.

From what I hear, the -01 chip was unreliable. They redesigned it
and
rolled the instrument serial number base for the -02 version. They
built a bunch of those.

Then some bean counter decided to sell the IC facility to MAXIM.
Somehow, about the same time, the instrument serial number base got
rolled again.
MAXTEK still produced the -02 chip but lost the recipe and started
producing unreliable chips again. I understand that the IC
unreliability problems were not restricted to just this chip.

I don't believe anything about "lost the recipe". Semiconductor processes
are subject to variation,tolerances.They may have decided to take a
'shortcut' or 'improve' a step in the process,or had a bad batch of
material.

According to my sources, there's a serial number range in the middle
where the chip reliability is much improved. I'll revise the webpage
to make that more clear.

Mine's in that middle serial number range. Just sittin' on the shelf
waiting for someone to come along and get a great scope.
mike

The reason Maxim stopped making ICs for TEK is that they did not like
making them in low volumes,and demanded TEK do a "last-time buy".That's why
the entire 2400 line was killed off.