Recent content by arroz

BTW I was looking for VRAM and I found this! Perfect. This is exactly what I was looking for!

Hi, AA-style batteries leak all the time. I have a drawer with a bunch and every time I go grab one, there’s new leakage. We’re talking about less than 10 year old batteries. A friend ordered a BIOS battery for an old 486 already during the pandemic and it already leaked. Although I have...

Hi! Well that at least clarifies that mystery, i was wondering what was that chip. Yeah this is probably not a problem. I’m just surprised there’s apparently nothing protecting voltage from going in the battery or against the battery being installed the wrong way. Maybe the chip has an...

Hi! I'm thinking about adapting my LCs to use CR2032 instead of the prone to leak 3.6V batteries. However, I looked into the schematic and realized there is no diode preventing reverse voltage, only a 1K resistor. I powered on one of the Macs without any battery in the slot, and I measured...

@cgp its not just humidity. One of the LCs I have has the top shield with rust, the bottom one like new. Both shields were obviously exposed to the same amount of humidity. The difference is the materials. A magnet will attach to the rusty one but not to the pristine one.

Hi, I just fixed a 475 with a somewhat similar symptom, it would not see the onboard RAM (although it could see the one on the slot, but would play the chime of death way more often that actually booting). The problem was a broken trace between pin 4 of the first and second DRAM chips (DRAS 0...

Confirmed! I think I'll use the (missing) ROM SIMM pin for the patch. Not sure if I can do it today because my desoldering pump broke… but yeah, this machine will live again. :)

Well, problem found! Pin 22 (A4) on the video chip has a broken trace.

Hi! So just finished recapping. Board works but the washed out video problem remains. I managed to switch to (I think) 1 bit while barely seeing what's on the screen, and now I have the entire screen displaying gray. Very weird… the investigation continues, and will have to install Timbuktu on...

Yep, I agree with that as well. I got an LC III and two 475s. I didn’t even turn the LC III on because it was very clear just by looking at it the caps were ruined. The 475 seemed better but were not great either. The first one I fixed had a broken trace on the on-board RAM DRAS line (maybe due...

Hi! I agree. Based on how bad the caps were on another 475 I just fixed, changing them alone may fix the issue. If not, at least it allows me to use it for a while without being worried I'm frying something else, so I can test with different resolutions and color depths to try to understand if...

Hi! I have an old Apple Keyboard II with some keys not working. For example, the entire column of the 2 key does not work. I opened the keyboard and I'm testing the membrane. Effectively, from one of the contacts of the 2 key to the connector, there is no conductivity. My question is… why...

Hi! Thank you for all your answers! All of this should point me in the right direction. I don't think I can avoid separating the shield from the case. To re-attach it, I'm considering borrowing an idea from modern Apple and use magnets. Glue magnets to the case, and attach the shield...

Hi! Restoration of an LC III is going great, board recapped is working perfectly! Now, the top shield is in a sad state (see photo). What's the best way to clean this? Assuming I separate the shield from the case, would a vinegar bath for a few hours work? What techniques do you use? The video...

Hi! I assume "Europe" in this context does not include UK. If it does, there's 1-bit rainbow, where I spend way too much money. They have the original, Apple chargers: https://www.1bitrainbow.com/parts-store.php?cPath=31_871_670_P3608&page=4 and...