Struggling to repair a Tek TDS5052B

[magnetchief]

Hi, I have an old Tek TDS scope.
The HDD had previously crashed, I had none of the original software for reinstallation of the drive.

I followed the excellent rebuild blog from Ilya @  xDevs  https://xdevs.com/fix/tds5000b/#result

I replace the HDD and cloned the image as per his blog.
Added more Ram and replaced the processor cooling fan.

After booting up, the scope seemed to work as expected.
I installed the various windows and Tek drivers again as per his blog.

I ran the various diagnostic testes and all passed.

But, I have no waveform displayed on the scope from either channel.

I tried to set a couple of measuring options using a PTS input into channel #1. You can see the measurements of the input signal on the attached photos, but no waveforms are visible.

Am I missing something here? Please forgive my lack of experience, but would really like to get this old scope working again.
Many thanks for any advice offered.

[Johnny10]

Someone had this problem a while back on another thread.

https://www.eevblog.com/forum/repair/tektronix-tds7104-no-waveform-on-screen/msg1984160/#msg1984160

[magnetchief]

Many thanks.
I think you are onto something. 
I will check it out tomorrow and update.

Thanks again.

[magnetchief]

Well that took all of two minutes to correct.
You were spot on, thanks for the lead.

[Johnny10]