具有锁相校准失败的HP8703D

您好，经过几周不活动后，我们的HP8703B网络分析仪出现严重故障。
它显示一个警告：相位锁定失败。
由于设备已经过时，似乎无法修复它，所以我会在我们的大学部门尝试。
我用示波器测量了CW的输出，出现了一个2GHz左右的主频。
使用频谱分析仪可以看出其他几个频率的贡献如：CW = 200MHz - >输出= 950MHz，1.46MHz，1.5MHz，2.2G，2.4GHz贡献CW = 1GHz - >输出=
990MHz，1.45MHz，2.4G，3.8GHz等小贡献CW = 2GHz - >输出= 950MHz，1.46MHz，1.5MHz，2.2G，2.4G，4.7GHz，...... CW = 9GHz - >输出
由7.18GHz组件控制我不知道问题可能是什么，可能是控制器？，振荡器或参考参数？
不幸的是，我只有用户手册，并没有找到HP8703B的服务手册来检查。
但是我看过一篇关于HP8753 NA类似问题的帖子，这给了一些恢复NA的希望。
我非常感谢任何解决问题的建议并找到类似的服务手册。
最好的问候，victor5



     以下为原文

  Hello, after some weeks of inactivity our HP8703B network analyser got a serious failure.
It shows a warning like:  Phase lock cal failed.
As the equipment has get obsolete it seems impossible to repair it, so i will try that here at our university department.
I measured  the output in CW with an oscilloscope and one dominant frequency around 2GHz appears.

with an spectrum analyser it can be seen the contributions of other several frequencies like about:
CW= 200MHz -->  the output has= 950MHz, 1.46MHz, 1.5MHz, 2.2G, 2.4GHz contribuitions
CW= 1GHz -->  the output = 990MHz, 1.45MHz, 2.4G, 3.8GHz and other small contributions
CW= 2GHz -->  the output = 950MHz, 1.46MHz, 1.5MHz, 2.2G, 2.4G, 4.7GHz,..
CW= 9GHz -->  the output is dominated by a 7.18GHz  component

I have no idea which the problem could be, perhaps the controller ?, the oscillator or the reference parameters?
Unfortunatelly I have only the user manual and did not found a service manual for that HP8703B, to check.
but  I have seen one post about a similar problem with a HP8753 NA which gives some hope to recover the NA.
I would appreciate very much any recommendation to fix the problem and to find a similar service manual.

Best regards,  
victor5