HP182T scope horizontal amplifier problem

[rodd]

Dear all,
I am trying to restore this instrument so I could use with an HP8559A that I could buy for a reasonable price.
However, when I tried to use the 8559A , all I could get was a vertical line, so I discovered that the horizontal amp is not working....
I read the troubleshooting charts but they pointed to very serious damages (CRT) so I decided to igore them and use the "basic troubleshooting method" : inject a signal on the external horizontal input and follow the signal.
So I injected a 1MHz signal 1Vpp at this input and I could see a signal up to the left side of R15 on the scematics.
From that point on, the signal drops to almost zero..
The voltages are close to the ones shown on the schematics and I have checked all the resistors close to this point (in circuit) and they seem to be ok.
I have no idea of what to do next.
Any suggestion?
I have attached a copy of the schematics below.
Thanks to all

[m k]

Start checking stated voltages back from deflection plates.

[BlownUpCapacitor]

Check CR2 or Q3. They might be shorted and could be pulling the signal low.

Edit: the schematic is sort of low resolution and I can't clearly read the component number designations. I assume R15 is the 15k vernier pot as shown here.