Sean Bruno

Having just restored a couple of power supplies, I can say that Console5 kits are the way to go. Match up your part number to theirs and then add the rifa caps you need from their stuff. If you have questions about which kits to buy, just ask them, they have a quick turn around on orders. If you really want to future proof, the all in one power supply kits are the most reliable and stable solution IMO. https://www.reactivemicro.com/product/universal-psu-kit/ I've replaced capacitors when the power supply was still working, but had lost their rifa and other electrolytic components. I've also put in replacement kits when the transistors or transformers had failed. I hope this helps a bit.

Apparently it is. Heh, how silly I didn't see this snapped winding. Thanks to the EE in a TV repair shop in this video that showed me how to trace out the windings in a coil for this kind of issue.

Hmmm ... part of the coil winding appears to be snapped. Is this repairable?

Unsurprisingly, Apple and Hitachi have responded that they don't have the schematics for any of this stuff. I've grabbed the ReCap kit from Console5 and am going to try and do different voltage checks.

This board is connected to the CPU socket, right? I am assuming the 65C02A is your Apple iic CPU. The NEC D780 googles up to a z80, I don't know if this is a math co-processor expansion or a way to get Z80 CP/M features into a IIC. Google failed me on looking for an example of this, but it probably is the only way to expand things in the IIc with its compact form factor. If you wanted a mockingboard, for example, you have to use your cpu socket as the expansion "slot". https://www.ebay.com/itm/284305317956

Now to hunt down schematics for the Hitachi family around the NP53C family.

Thank you for eyeballing it. At least I can move onto trying to do more than just visual diags now.

Based on a random thread from a different forum (https://comp.sys.apple2.narkive.com/99TAxRvv/apple-composite-monitor-iie-help-needed) I inspected R741 and its very discolored. It measures nearly a short now, but I can't really tell from visible inspection what it used to be.

I've started work on a sickly A2M6021 CRT monitor. It seems to be in decent shape (from an elementary school auction) with some analog issues. The vertical retrace seems to not be returning to the very top of screen nor making it to the bottom. I haven't been able to hunt down the schematics or SAMS for this CRT. Does anyone have a copy that they can share? If not, does anyone have a starting point or a hint for this type of failure? (obviously, I'm using all ESD discharge and safety here, I have some training on tubes and high voltage)

I was able to remove the tape and clean the entire PCB with IPA. After replacing with fresh tape and reconnecting, it sprang back into life. We had a Missile Command tournament via my 800xl and it was glorious.

I've come into possession of a super clean CX-22 that has failed fire button circuit boards underneath the buttons. I just did continuity tests on them and they both fail. Does anyone have a line on replacement or repair processes for these little guys (CO20561-1)?

Wanted to drop a thanks into this thread. I picked up an 800xl on eBay while enjoying an adult beverage recently (don't drink and eBay!) and finally got it up and running. It would instantly drop to RAM test on power up, which was a good sign. I pulled all 8 MT RAM ICs via a hot air station and added some vintage red sockets I found at Edgar's Digital in Las Cruces, NM. I swapped out the MT 4264-15 with some TI 4164-120 that I had in inventory, all seemed to come back to life and it was pretty amazing. I tested all 8 MT RAM ICs one at a time, the RAM check failed on 5 of them. Photos of various different RAM failure modes are on twitter if you want to see what it looked like in the end.