Schneider CPC464 restoration and weird board

[SilverGreen93]

Hi,


My Schneider CPC464 computer has an odd motherboard. I have never seen a photo of this revision and/or a schematic. The motherboard was totally shielded with metal sheets. I desoldered the sheets and thrown them away as they were almost 100% rust. The Schneider itself was in a very bad condition. Thankfully I managed to restore it in an almost-as-new condition and perfect working order.


My question is, what kind of components are the "PF" ones from the board? There are tons of them and they look as some weird sort of capacitors, but they have 3 pins...


I attached the photos of the motherboard. (Soon photos of before and after cleanup)


Things that I've repaired:
1. Tape belts.
2. Tape pause button.
3. Some broken capacitors from the tape head amplifiers.
4. Play/record internal switch that wasn't making contact too well and shorted the play-head. Disassembled it and fixed with Kontakt 61 spray.
5. Removed rust and ditched the metal shields.
6. Cleaned all the keys individually.
7. All the key springs were very rusty, but fortunately I managed to make them shine again using some Kontakt 61 spray and let them soak over night.
8. Other general cleanup (case, tape heads, rollers etc)

Now, after about 1 week of repairing I'm truly happy with my "new" Amstrad.

[robcfg]

Glad you got it working!


Regarding the pictures, we do have the MC0008C board scanned in the wiki Mainboard versions page.


The PF parts seem to be filters.

[pelrun]

Those are really weird parts; looks like it's a discrete RLC circuit with the parts potted together. It's three pins because one of them goes to ground.

[Bryce]

The weird parts are small signal chokes with a grounded shield. Amigas are full of them, but they're a lot smaller in Amigas because of newer technology.

Bryce.

[SilverGreen93]

Thanks for replies!
Ok, so as I understand, the Schneider was designed to be very EMC compliant.


Here are the pictures before restoration and after.


Only one mod that I've made: An input 3.5mm jack for the External tape/audio connected to pin 7 of IC302.