Questions about leakage in the vintage IBM8306
Questions about leakage in the vintage IBM8306
Guys, I have this old computer here—an IBM 8306—that was left unused in a corner. Out of curiosity and some hobbies, I tried to turn it on. Unfortunately, it didn’t work, maybe there’s an issue with the HD. Before making any changes, I’m concerned about possible shocks when leaning back in the cabinet. I took pictures using a test key to check for an energy leak. What should I do? Is there a way to confirm the cause? Or should I just sell it as it is? Thanks.
This device is sufficiently outdated that I couldn't locate a technical sheet online...
If it's truly very old, it might be beneficial to dismantle it at the component level and examine each part. I wouldn't suggest entering the power supply unless you're familiar with the work being done inside. The capacitors there could pose serious risks or even danger. You can check the pinout and test basic operation for simple checks. I'd review the main board to confirm no capacitor has failed or leaked, which might have led to further problems. Also verify that nothing is improperly grounded to the case.
In any case, this situation offers a chance to clean the components, gather model details, take photos, and provide more info for someone who might buy it later.
A weak ground in your home's electrical system can lead to similar problems, but we're assuming that isn't the issue here.
Does your power outlet have a correct ground connection? A basic plug checker can verify this.
Class-Y capacitors within the PSU (likely around 0.01 or 0.1 microFarad) may discharge a minor current of a few milliAmps toward the chassis. If the mains earth is absent, a high impedance route will exist to the Line and Neutral connections.
https://www.allaboutcircuits.com/technic...apacitors/
My assumption is that your mains safety earth is not present at the plug or outlet. Address this immediately! Without a proper earth connection on the chassis, a malfunctioning PSU could pose serious danger.
The 400V DC bulk electrolytic in the PSU will stay active for some time after disconnecting the computer from the AC mains. Proceed cautiously when inspecting the internal components.
Thank you for your support. Yes, though the assumptions might hold (missing capacitors and safety earth). I’m considering donating.