Problem with my Anthem AVM20 - display screen

Best wishes everyone. I'm a new member, this is my first post. Thanks for reading. 

About a year ago, I wanted a new preamp because 2 RCA plugs  on my Marantz preamp stopped working.
Thought of finding a repair man but also started looking for a replacement preamp. 
Found an insane deal on a used Anthem AVM20 pre & Anthem PVA 5 power amp bundled together on ebay.
I had the AVM20 for a year now with no problems. I never used the PVA 5.  It was sitting in a closet ever since I bought it, but finally I pulled it from the closet tonight, connected the PVA 5 for the first time. 

I was careful & disconnected all the plugs & depowered my power strips before disconnecting anything. 
After I turned everything back on, the AVM20 display screen, which looks like a dot matrix printer, ALL the dots lit up. 
All I see are blocks of dots. The screen is unreadable.  It never did that before. But the audio was fine.  

I removed the PVA5 & reconnected my old amps. The audio is good, no damage to anything, except the AVM20 screen is still bad, as described above. 

Am wondering if anyone saw this problem before & what to do about it. 
Maybe I should consider another preamp if my AVM 20 will be expensive to fix. 

Somebody on Craig's List  is selling a Proceed AVP for $550. Is it worth looking into or is it too old ? 
I use my gear equally between movies and music CDs.  For movies, 5 channel is what I use. 
Don't think I will ever have 7 channel.  

Thank you, 
Dave