POWERSCOPE II Ser. Nr. 57783, burned part

The powerscope is at least 25 years old. But it has been in well function until last week.
The problem is R702 near the Input  of the Power supply, who has been completly destroyed.
Therefore I cannot read the typical features.

Is there anabody, who can help me?

Dipl.Ing. Wilhelm Seper
Marktfeldstrasse 5
7423 Pinkafeld
Austria

seper@bnet.at