Avo Megger BM80/2 beeping and shows E44 on display.

[Paceguy]

I have an Avo megger model BM80/2 that when powered up beeps and shows E44 on the display no matter what position the function switch is in.
I looked online to try to find the service manual with no luck. Help would be greatly appreciated. Thanks in advance.

[trobbins]

I have schematics for BM80-400 Mk2 - PM me.  I have progressed some repair of my BM81/2, that also showed an E44.  So far I had to replace an LM324 to recover a bad 2.5V reference line, and replace an LM339 to recover its nominal input node voltages, but BATTOK line is still pulled low when I think it should be nominally hi, so WIP but I last had this on the bench last year.

Ciao, Tim

[Paceguy]

Thanks Trobbins, I will check that out.