开云体育

Interesting dead bug looking patch in the last picture
John

On Sep 23, 2020, at 12:44 AM, Thomas Garson <tgarson@...> wrote:

?My "new to me" TWD120 arrived today. Thank you Charlie.

As Charlie advised in previous email, it did not pass self test, leaving the front panel LED unmistakably solid red.

However, the repurposed IBM laptop external power supply worked admirably so I dove into it.

After removing a number of screws and a cal sticker, I was presented with a single nice and compact SMD loaded PCB. No out-sourced PWM supplies for Tek. The regulator circuitry occupies a compact "can" in one corner.

As I was working w/o a schematic I had to find supply lines on some chips to check voltages. Voltages were good, but one was a bit noisy. DC to DC portion of supply looked good on (Tek 5000) scope. After sniffing around a bit (figure of speech. It did not smell) I noticed several Motorola T10N05e TO-263 type SMD packages near the supply wall, but outside of it. At first I was puzzled as I could find these parts for sale but no data sheet. Figured out they were N-channel power mosfet. I determined they were used for gates to enable/disable DC power feeding from the supply. Interesting. Squinting trough my trusty Swiss Army Knife magnifier (glass lens!) I noticed serious corrosion on the Source solder connection of one of those FETS (Q104: +8v line), which I theorized may have been the source of the noise I has seen. Reflowed the funky joint. Kicked on the power, waited a minute or so for self test to complete: Bingo! LED now turns Green!

That's as far as I got today. Next thing is I have to pull the software for it off of the floppy discs (fingers crossed) for copying over to the server and then burn a back up disk. After that, get my Win98SE PC set up with SCSI (not too big a deal as I used to do a lot of SCSI stuff) and see if I can actually get the thing to work. At the moment, I'm fairly optimistic this will happen in short order.

A few photos here:


Thomas Garson
Aural Technology, Ashland, OR
By my calculation, the dynamic range of the universe is roughly 679dB,
which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps.

"Apparently even Tektronics was not above a well executed kludge."
Please stop this. Bad enough in ebay listings, but here?

This came directly to me from snapdiode, whoever that is.

I was under the impression that my posts were directed to a group dedicated to the
use and maintenance of Tektronix equipment.

If that is the case, this is a pretty rude message from someone who probably should
know better.

If the inclusion of humor in posts is excluded from that group, I will remember to
avoid its use. I wouldn't want to offend someone I was helping by every word not
being curt and dead serious.

If its about my inadvertent misspelling of Tektronix, get a life! There are much more
diplomatic, and to the point, ways to point out grammatical errors than rude emails
with vague innuendo.

If my posts are somehow not going to the Tektronix group, I apologize and ask that I
be informed of that, and perhaps provided with more useful commentary on how I might
make the needed correction.

Thomas Garson
Aural Technology, Ashland, OR
By my calculation, the? dynamic range of the universe is roughly 679dB,
which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps.

On 9/23/20 9:43 AM, snapdiode via groups.io wrote:

"Apparently even Tektronics was not above a well executed kludge."

Please stop this. Bad enough in ebay listings, but here?