Recent content by Big Ben

Thanks for share all this information. My SE is in the store since I discovered the Prodigy was not compatible with Super Drive. I will pull and get more information about my board. Also my board doesn’t boot on cold boot, it sad mac and I need to reset it… Is your Mac SE equipped with super...

Sounds like a bad solder somewhere. By manipulating the board you may have trigger a problem that was just going to happen anyway. By replacing the caps, you may need to calibrate the display, I wonder if there is a service manual for this screen but they usually have instructions. From what I...

Replacing the original thermal pad, with a new thick one (because it’s the only thing I had) I made it stable with a fan blowing on the heatsink. The ceramic package is our enemy here, but it seems 166MHz also existed with this packaging. So I’m tempted to try the 2.5 multiplier. Could I push...

Freeze and reboots 😔

None I’m aware of. The card should support any P54C socket 5 CPU. Yes but as mentioned by Byrd, it requires the original CPU to be removed, that’s a 298 through hole pins monster to get out of the card with damages. I’m tempted to do so, but I don’t want to ruin the card and I need did...

Hello, This is a work in progress thing, since it’s not stable. The Pentium on the compatibility pc card is a P54C socket 5 processor. It runs on a 66MHz bus. The Pentium has two inputs pins allowing the internal clock multiplier to be configured. Those pin are BF0 and BF1. Both are pulled...

Ok so there is a 74F32 near the quartz that could be involved in the clock multiplier. But I can’t found anything about the sc464ayb. I’ll try to find out the circuit, I fear the 166MHz-P to be really different and not comparable to the 100MHz one

I suppose the bus to be 66MHz with 1.5x multiplier but it also could be 50MHz with 2x multiplier. I can’t check it right now, my 4400 is taking a bath (literally) but I would check on mine asap.

That’s… just brilliant ! For two reasons 1) P54C seems to be quite a beast when doing overclocking, I saw some reports of 100MHz P54C running up to 180MHz, early P5 seems to go up to 100MHz. 2) Even with an other faster CPU I totally forgot we had to deal with the clock multiplier ! Ramping...

I did put mu 12’ 100MHz PC compatibility card out from storage and did some testing with my 4400/200. Despite being « not compatible » with this computer it worked fine. Using a Compactflash as an hard disk thing is quite fast! At least for a 100MHz card. I did order VRAM chips to upgrade the...

I can confirm, I used to have same problems. Also, despite being glued, mine had the green signal damaged between the connector pin and wire. It’s worth checking. For the rest as 8tto said, you need to follow the service manual on the screen calibration, but just remember to only use plastic...

Hello Did you replaced the motherboard and analog board capacitors? Looks like the power supply can’t stabilize, which usually happens when the capacitor on the analog board goes wrong.

That's interesting, I guess you are right it's quite a late motherboard revision as it's copyrighted 1990-1992 and the LC was discontinued in 1992. Since the dual floppy configuration was not very popular, Apple certainly did some cost-saving changes while preparing the LC II.

Little update: did some resoldering, now working fine even when cold. I guess it’s another saved color classic! 😀

Kemet is the new owner of Rifa IIRC. They are definitely damaged. White one usually cracks from top. Yellow ones on the side. I’ll look for the replacement part.