Do you believe this?

[jebem]

(02-08-2019 03:09 PM)Jlouis Wrote:  This is a 32S that I was negotiating to buy. The display was very dark, although the calculator is mint. I asked the vendor some pictures and he sent me this. He made a video of the calculator on.
The batteries was LR43. I don't know if the lr43 is smaller, but looks like it is.

Is the display darker because of extra 1.5V? Was a capacitor or resistor damaged? Well, I can't answer these questions.

Edit: the vendor told me that they're fresh newly installed bateries

To answer your questions:

1.- The calculator can stand to work at 6 VDC for a while, like a few seconds.

After that, the screen may go totally dark as the seller describes, even when adjusting the contrast that will look like nonoperational.

After entering this black screen situation, even using the correct 4.5VDC, the machine will stay apparently inoperative because the screen is black.


2.- Will the machine be destroyed by running it a 6VDC?

The voltage increase is not that large for a circuit running on very low current consumption to be able to cause hard failures.

At 4.6VDC the current consumption is 1.2mA avg when pressing keys, and 1.7mA when working at 6VDC. Not a problem for the electronics inside.

Capacitors failing? Well it can fail even when working at the nominal voltage.
Installed caps surely can stand and 1.5V increase without failure, unless there is a design flaw in first place, which I don't think exists on these machines.

To restore the normal operation, remove the batteries and connect a wire between the battery terminals for around a minute or so.
Then use the correct batteries running at 4.5VDC and you should see the memory clear message again.

Then use the contrast adjustment to set the preferred setting.


3.- I have used one of my 32SII to test the above, using a lab power supply.
I do not have a 32S, but I assume that the 32S model behavior may be similar.

To summarize, it looks like the issue can be fixed by just clearing the voltages inside the machine and then using the correct 4.5V.
The symptoms you describe matches what I have reproduced in my machine.
It would be really bad luck if your machine has more than one issue.

So to be safe, I would ask the seller to restore the machine operation by doing the above procedure.
Unless you want to take a chance and the asking price is really low...