Trace panel beep beep beep

it beeps 7 time every second, how could you could that fast haha.  

when you start trying to rebuild thoes older units it sometimes turnes into a lot more work than you figured.  some times it is just easier to replace the whole thing with a new converter/charger.  you just need to figure out what rating yours was and go from there.  It will also give you the ability to upgrade to LifePO4 house batteries if you want.  One I would recomend  looking at is a Victron multiplus 2.  there are a few benifits to this one, you can take 50 amp power in and it has dual 120V output built in and will monitor both legs.  older or cheeper ones you need to buy two if you want dual legs out.  it also intagrates your batteries and shor power so in some situations if you are staying somewhere that only has 15 amp power and you want to use a AC it will combine battery power to make up the extra you need that the 15 amp shore power can't provide.  also if later on you decide to add battery monitors, or solar controlers, they all link togeather for easy monitoring and control. 

depending on the output you have for example a 12V3000VA output inverter/charger by victron will run you about 1000US.  so a bit more than double what just the panel for the old one is, plus instalation if your not capable of doing it your self.  then there are different control panel options you can add, or just use your phone and use that space for somthing else.  if you need a bigger output you could jump up to a 5000va output.

thats just one option but then your getting the latest technology and a 5 year warenty.  there are other more budgit option with 1 year warenties and so on, or like you said you can buy a used panel and hope it is all good.  

I can't speek to using other controler panels with your unit as I don't have a picture of it and what it does, but most will probably not work, unless it is made for that.  most still use the "phone" plug, but its the protocol they use to comunicate that is the issue.