Search results

i dunno, I suppose YMMV. ive cleaned pots before and have never had trouble. 

that line is also very dim. should be much brighter than that unless you turned the brightness down, so id look at UE8 too. 

Youll still likely encounter cap damage even when NOS, so youll have to recap it for sure. Assuming it hasnt damaged the board already. 

it seems dark enough that your CRT might be weak. That is always a possibility. 

It is going to take a combination, with the potential of yoke adjustment. you will have to experiment. 

Not typically, if you cant change the title, then maybe we can get a moderator to do it. @Gorgonops or @Cory5412 if they wouldnt mind.  Anyways we will just continue on from here.  Yea, I figured the groundwire was an issue. Hopefully it didnt damage anything. but I bet it did. you may need to...

That typically cannot happen unless the CRT is not grounded. the CRT has to be grounded. there is usually a ground wire that connects up to one of the screw posts, and then works its way back to the neck PCB. make sure that wire is in-tact, and the solder joint is good on the neck PCB. also make...

Yikes. I dont even know what to say about this one.  but that "pop" was the sound of something getting damaged/blasted. Assuming it wasn't an arc-over in the CRT itself. 

Yea, but its not a tuned circuit, at least not the feedback portion of it. It isnt supposed to do that. You can try DeOxit, otherwise you can replace the pot. you would need to match up the specs, and footprint to something modern on Mouser or Digikey. 

Then you have glitches in your power rails, or the NMI signal. 

Could be a bad potentiometer, developing dead spots. 

Could be a multitude of things.  One, could be the power supply itself not supplying clean power, or high enough voltages.  It can equally be the NMI pullup connection open, or button bad, it could be any of the chips on the logic board, many things unfortunately. Could even be a bad copy of...

This and many reasons is precisely why im not married, and love being independent. 

something ive never been able to master. 

Oh, that makes it even more fun to figure out. :-/ The power supply stage is VERY different than that of the 5120. 

Thats a bad PMGR/Hybrid. Very common, and short of that, could be caps/resistors support components in the circuitry between them. 

If it shorts, it'll send 6V to 7.5V to all the 5V chips which would fry everything up stream, basically bricking the board. I have seen it. its rare though. The first thing it takes out is the SWIM, and a handful of 74 series logic next to the CPU. 

Yea I dont know of any solution for that type of topolgy unfortunately. you can do it all day long if you have Appletalk and some type of ethernet networking whether its over SCSI or Serial, or something.  Appletalk over a wifi modem I dont know if its a thing yet, since in the Mac domain...

Dead machine. its the 5.2V regulator.