Andreas Thaler
Subscriber
Today was check of my T90 family.
Some with no findings, some with the shutter blades stuck together, one with a crazy display and this one that shows nothing on the display after switching it on.
That struck me as odd, since it had worked the last time.
So something must have changed in those few months.
Always the first assumption for batteries with sufficient voltage:
Contact problems around the battery compartment.
My suspicion was confirmed when I discovered green acid residue on the bottom of the battery compartment. Not much, but telltale ;-)
Cleaning the contacts in the camera and the battery contacts did not change anything.
The T90 continued to refuse service.
So I had to check where the error is.
Battery compartment removal
And here is the reason for the refusal to operate:
The black ground wire had come loose from its soldered joint in the battery compartment.
No wonder given the severe corrosion of the soldering points at this location (arrows).
Another example of how forgotten batteries in a camera can take revenge.
Without a ground connection, there is no circuit.
No function without circuit.
Here is a view of the contacts in the battery compartment from the user's perspective when the camera is closed.
Little corrosion visible. But behind it it looks bad.
The soldering iron was in demand.
Meanwhile the battery compartment was bathed in Durgol descaler solution diluted with water to get rid of the corrosion.
The black ground cable no longer seemed safe to me. I replaced it with a new one.
Due to the corrosion, the soldering point on the circuit board also came off while working.
I therefore had to bridge the spot with wire in order to connect with the ground cable.
To keep the cables on the left away from the soldering work, I fixed them a little further away with Loctite.
The battery compartment after cleaning in Durgol.
The green acid residues have been removed. Some rework with the probe, but the contacts are ready for soldering.
The battery compartment is again connected to the circuit board via three cables.
After assembly, a test with the battery holder inserted.
Yes, the T90 was back!
The display was on - tock, tock, tock, the shutter pounded.
Alive again
Some with no findings, some with the shutter blades stuck together, one with a crazy display and this one that shows nothing on the display after switching it on.
That struck me as odd, since it had worked the last time.
So something must have changed in those few months.
Always the first assumption for batteries with sufficient voltage:
Contact problems around the battery compartment.
My suspicion was confirmed when I discovered green acid residue on the bottom of the battery compartment. Not much, but telltale ;-)
Cleaning the contacts in the camera and the battery contacts did not change anything.
The T90 continued to refuse service.
So I had to check where the error is.
Battery compartment removal
And here is the reason for the refusal to operate:
The black ground wire had come loose from its soldered joint in the battery compartment.
No wonder given the severe corrosion of the soldering points at this location (arrows).
Another example of how forgotten batteries in a camera can take revenge.
Without a ground connection, there is no circuit.
No function without circuit.
Here is a view of the contacts in the battery compartment from the user's perspective when the camera is closed.
Little corrosion visible. But behind it it looks bad.
The soldering iron was in demand.
Meanwhile the battery compartment was bathed in Durgol descaler solution diluted with water to get rid of the corrosion.
The black ground cable no longer seemed safe to me. I replaced it with a new one.
Due to the corrosion, the soldering point on the circuit board also came off while working.
I therefore had to bridge the spot with wire in order to connect with the ground cable.
To keep the cables on the left away from the soldering work, I fixed them a little further away with Loctite.
The battery compartment after cleaning in Durgol.
The green acid residues have been removed. Some rework with the probe, but the contacts are ready for soldering.
The battery compartment is again connected to the circuit board via three cables.
After assembly, a test with the battery holder inserted.
Yes, the T90 was back!
The display was on - tock, tock, tock, the shutter pounded.
Alive again

Last edited: