Tektronix 2467B display issues help

[Lightbeing]

Hello,
Just bought a Tektronix 2476B scope and have found a couple of issues so would be very grateful for any help.
1 - There are a set of flickering dots in two raws showing at the top and bottom of the screen display.
2- When the measure button is selected. The display readout brightness becomes overwhelmingly bright across the whole screen and the brightness becomes uncontrollable by the readout intensity knob apart from turning the measurement off.
Many thanks for your help!

[GerryBags]

Hi there, I think you too may have leaky SMD electrolytic capacitors on the control board A5. I had a look at the display troubleshooting chart in the SM, and the ICs it recommends checking (those around U2980 on A5) are near the cap on the left hand side of the board, and is between it and the air outlet.

Have a look at this thread (https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/), the 2465B and 2467B have the A5 control boards in common and share a service manual. I'm just fixing a display issue on my 2465B which I've traced to the other side of A5 but the same issue: leaky SMD caps and corroded pins. I have a 2467B that doesn't have this issue yet, but I'm going to change the caps on it's control board at the same time. I've also been adivised to change the NVRAM that holds the cal data, this is also covered in that thread.

I think your first step is to have a look at the A5 board, particularly around the electrolytic capacitors near the top of the board. I found that taking a high-res picture of the area allowed me to see things that were beyond my naked eyes, and then you can post it here, too! 

That extremely useful thread also has links to lots of resources you will find useful, too, you will definitely want the full Service Manual if you haven't got it already.

edit to add link to thread I've been raving about 

[Lightbeing]

Hi Gerry. Thank you for your message and the tips.  It was my first time here on the eevblog forum and first time owning a real scope. Well I’m only 57 years young lol.
Here is another video showing the issues perhaps more clearly https://www.bitchute.com/video/7w8h3k1Ntc2N
The person i bought the scope from is willing to take it back as it was sold fully working but i am in two minds as to whether I should return it or keep it and repair it.
I will definitely be posting photos if I end up keeping it and have the courage to take this gem apart.
Thanks!

[Testtech]

It might be leaking SMD caps on the control board, if the serial number is B05xxxx or greater. Or, the CRT Bias pot is too far advanced.
If it is leaky caps, there are several posts regarding remediation.
Be careful with the Microchannel plate crt, it can be damaged by excessive intensity.