Author Topic: 2467B with a strange horizontal issue - video link  (Read 6414 times)

0 Members and 1 Guest are viewing this topic.

Offline Teknow

  • Contributor
  • Posts: 34
  • Country: cy
Re: 2467B with a strange horizontal issue - video link
« Reply #25 on: April 01, 2017, 05:53:44 pm »
 I have been curious wether humidity plays any significant role in the degrading performance of the U800, but I was wrong. I used a hair dryer to blow a stream of hot air through the ventilation slots while placing a fan to draw the air from the rear for a few minutes. After switching the oscilloscope, there was no trace. So it's the heat that causes the U800 to strike!
I placed an air blower type fan against the ventilation slot of the U800, and after a few minutes I turned the oscilloscope on, it worked fine until I pressed the X10 MAG the trace began to fade away to the left after distortion of the wave!

I read some interesting ideas on "baking the U800" and avoiding mechanical stress to it.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15397
  • Country: za
Re: 2467B with a strange horizontal issue - video link
« Reply #26 on: April 02, 2017, 02:02:16 pm »
There was a thread to replace the U800 chip with a discrete solution on a header board.

http://www.davmar.org/TE/Tek2465/lafay.html

Might be a worthwhile thing as a replacement. Original EEVblog thread ( or at least the first Choclate factory result) here https://www.eevblog.com/forum/beginners/oscilloscopes-to-stay-away-from-(spec-tek-2337-question)/msg275455/#msg275455
 

Offline Teknow

  • Contributor
  • Posts: 34
  • Country: cy
Re: 2467B with a strange horizontal issue - video link
« Reply #27 on: April 03, 2017, 08:46:00 am »
Many thanks Sean, I wrote to his Email in the following site but it seems it's no more valid
https://msu.edu/~lafaytho/

I'll give the Chip another heat sink and fan.

If all U800 afflicted 2265/67 owners would cooperate and share ideas, expertise, and technical infos, we would surely devise a substitute.
I know  an RF engineer with considerable practical and theoretical a.o. television repair experience and know how who promised to tackle the problem but not before September.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf