My 83+SE acted up the last time I went to use it after not touching it for about a month and using it every few months regularly before that.
What its doing:
- Not turning on or showing any activity
- If it does turn on, its not a fully black screen, but it is not random and looks the same each time. Pressing other buttons in this state has no effect (e.g. CLEAR, typing numbers and operators, etc., does not affect what is displayed on the screen in any way), however I can turn it off with 2nd+ON. So I have the impression that this isn't an issue with the screen or ribbon cable. (I'll try and get a photo of this, but I've not been able to get it turned on again in the last hour or so).
What I've done so far:
- Pulled all batteries, waited a few minutes and attempted a RAM clear (batteries all new and also measured to be in good voltage even under load)
- Opened the calculator and cleaned off all contacts used for battery connection (the pads for the main batteries were worn through, the pad for the backup battery was heavily worn but still making contact).
- Quick visual inspection of the PCB for any corrosion, damage, etc.
Odd things:
- If I can get it to turn on and show the aforementioned pattern on screen, I can turn it off and back on all day long. If I remove a main battery, wait a moment, put the battery back in, there is a good chance it will no longer turn on any longer. Sometimes if I leave a battery out for 10+ minutes and put it back in can I get it back in to a state where it is turning on and off again.
I've not yet done a detailed inspection of any of the solder joints or measured the LCD ribbon cable continuity; I'll do that when I have time and update the thread when I do.
Thanks in advance for any next debugging steps that you can recommend.
What its doing:
- Not turning on or showing any activity
- If it does turn on, its not a fully black screen, but it is not random and looks the same each time. Pressing other buttons in this state has no effect (e.g. CLEAR, typing numbers and operators, etc., does not affect what is displayed on the screen in any way), however I can turn it off with 2nd+ON. So I have the impression that this isn't an issue with the screen or ribbon cable. (I'll try and get a photo of this, but I've not been able to get it turned on again in the last hour or so).
What I've done so far:
- Pulled all batteries, waited a few minutes and attempted a RAM clear (batteries all new and also measured to be in good voltage even under load)
- Opened the calculator and cleaned off all contacts used for battery connection (the pads for the main batteries were worn through, the pad for the backup battery was heavily worn but still making contact).
- Quick visual inspection of the PCB for any corrosion, damage, etc.
Odd things:
- If I can get it to turn on and show the aforementioned pattern on screen, I can turn it off and back on all day long. If I remove a main battery, wait a moment, put the battery back in, there is a good chance it will no longer turn on any longer. Sometimes if I leave a battery out for 10+ minutes and put it back in can I get it back in to a state where it is turning on and off again.
I've not yet done a detailed inspection of any of the solder joints or measured the LCD ribbon cable continuity; I'll do that when I have time and update the thread when I do.
Thanks in advance for any next debugging steps that you can recommend.