Help finding a power/sweep board

[shroom2021]

I just got a macintosh classic and when it turns on the screen only displays a vertical squigly line that warbles. I can hear the harddrive spinning up over and over and according to the troubleshooting guide that indicates a problem with the power/sweep board. The problem I am having is that I can't find a tested board for under 250. I only paid 40 for this and was hoping not to go over 150 on the project as a whole. I've got an oscilloscope and multimeter, so I'm going to grab the schematics and try to TS it myself, but it would be much faster to just replace the board if I can. Does anyone know of a good marketplace for something like this? Ebay is really hit or miss for me.

 

[Josh]

I just got a macintosh classic and when it turns on the screen only displays a vertical squigly line that warbles. I can hear the harddrive spinning up over and over and according to the troubleshooting guide that indicates a problem with the power/sweep board. The problem I am having is that I can't find a tested board for under 250. I only paid 40 for this and was hoping not to go over 150 on the project as a whole. I've got an oscilloscope and multimeter, so I'm going to grab the schematics and try to TS it myself, but it would be much faster to just replace the board if I can. Does anyone know of a good marketplace for something like this? Ebay is really hit or miss for me.

My first guess would be the capacitors on the board, at 30+ yearst they tend to dry or leak, it's pretty easy to swap them out and we have a capacitor replacement guide on the wiki https://wiki.retrotechcollection.com/Macintosh_Classic_Capacitor_Replacement_Guide. The second thing to check is for cracked solder joints on the back of the analoge board, I'd give all the cable connections a reflow with fresh solder.

The good thing is you have stable power on the board, the hard drive spinning is a good sign, it just seems like you've lost horrizontal deflection. Do you hear the start chime?

Where about's in the world are you, I might be able to source you an analog board if all else fails.