Greetings.
I got my hands on this older Fluke 8810A multimeter.
Of course, I immediately turned it on and the display just flashed and it was dark. But when I opened it, I couldn't believe my eyes - the switch was in the 115V position. Of course, farted insurance.
A normally prepared spare inside, I replaced it, the multimeter started up, the numbers are just running around, but even when measuring it fluctuates quite a bit, it depends on the ranges - the bigger the more it fluctuates.
I found the service manual and checked the voltages on the test points, on some it holds perfectly +18V - OK
-18V- so there is -24V
-13V - there is -19V
+7V - OK
-7V -OK
+35V and -35V are standard
The problem is probably in the circuit of the CR30 bridge. The power supply of the U18-NE5534N is -26 and +16, I don't really understand it - like +16V, I understand there is a 10V zener, but -26V goes directly from the bridge...
I tried everything I could, but I can't figure out what the problem is
I will be glad if you direct me if possible.
Thank you all for the answers 😀