Recent content by dkjones96

I got the turbo confused with the PowerPro. So many models of essentially the same thing.

It was just the settings resistors on the bottom. Two of them connect to the two unused address lines on the tag ram and the third one tells the power card that it is a 1MB module instead of a 256K. Isn't the turbo 601 already 1MB?

Pin held high indefinitely on an 030 Mac is almost always leaky caps around the sound chip freaking it out. The sound chip on these is in charge of reset.

SUCCESS!!! So, on the older non-Daystar branded 66MHz models they didn't run the highest 2 address lines correctly. When you add the cache chips that utilize those pads you end up with weird stuff like address lines connected to input-only GAL pins and one of them doesn't go anywhere on the...

Extension and control panel work great! Mystic Color Classic with fat 040' runs 40MHz at the click of a button. That being said, the Daystar PowerCard PPC upgrade does not like reassignment. I can only guess that it has something to do with the modified bios on that card. I can OC that system...

Tried the chip swap and, surprisingly, didn't even get the death gong? I also tried every combination of resistors I could on the bottom and got zero out of the machine. @hyperneogeo you are certain you got a death gong out of it?

That will 100% be the path I take. The new cache chips are in and will be swapped out, possibly end of the month. Gotta see when I get the courage to do it! I also now have a set of soldering tweezers so swapping the 0-ohm resistors will be a cinch. Last bit of research I need to do is make...

I am thinking of trying this same upgrade! Ha! Even ordered the same 128Kx8 chips. My GAL chip isn't socketed but I did notice that there are some R positions underneath the cache board with 0 ohm resistors across them. I'm guessing that the cache chip has to have a jumper setting change to...

Amazing, that was it! Popped a battery in there and it booted right up. Thank you!

I'm currently troubleshooting an LC475. Should the machine start up when the power supply is switched on or should it use soft power like most other 040 machines? This motherboard came to me with a destroyed R85 resistor. It's the big 6.8 ohm guy by the sound chip. I replaced it, along with...

Fortunately I don't think most of us use our compacts enough to 'really' worry about wearing out the CRTs. Keep the brightness down and you are good for 5K hours, easy. Might even squeeze 10-15K if you aren't afraid of a little burn-in and don't mind cranking up the brightness a bit later in its...

Fortunately they come up a lot so some decent prices can be had if you are patient. They come up WAY more than any other analog board and are much cheaper than most.

Only the red wire to the anode has high voltage on it. The deflection coils in the yoke all run on about 30V so as long as you don't mess with the big red wire the yoke is relatively safe.

Is it parallel on the left but not the right or is the whole image turned? If the whole image is turned you can correct that by loosening the yoke clamp on the tube neck and turning it a bit. It might be sticky after all these years but it'll come loose. Not sure why but pretty much all of my...

@ttb I did end up undoing it and then going with the old preferred way which is option 1 above. I kept having problems with a pair of diodes overheating an electrolytic capacitor in almost the dead center of the analog board. It runs crazy hot at 84v and stays that way even when the computer is...