Rolleiflex SL66SE light meter easily fixable?

[Garb]

I bought a used Rolleiflex SL66SE and the meter always overexposes by more than one stop in int mode (and even more in spot mode). After doing some tests by using spot metering and pointing it at a light bulb, I think the issue is that the center metering area (1 out of the 5) is disconnected / not working / under-sensitive, which is consistent with the observation that it overexposes more in spot mode than in int mode. Is this easy to fix?

So I went ahead and bought another SL66SE, figuring I got a unlucky the first time. This is one is even worse, the light meter doesn't turn on at all. Things I've tried with this second body:

- Tried two batteries, and made sure the green light turns on when using the test button. (Both batteries work in the 1st SL66SE body).
- Activate and deactivate the aperture stop-down
- Fired the shutter
- Tried three different film backs, in case the back is not transmitting ISO (these film backs work in the 1st body)
- Tried two lenses, in case the lens isn't coupled (Both lenses work in the 1st body)
- Tried removing the focusing screen in case it's blocking the LEDs for whatever reason
- Switching to various shutter speeds other than B
- Various apertures on the lens
- Run my finger down the contacts on the body which connect with the magazine (in case they are blocked by dust)

Anything else I should try?