Hello! My first post on here, so here it goes...
Since about a month or two I'm the proud owner of a broken Marty. I bought it to work on it as a project during these lockdown days.
First thing I did was strip the complete powerboard and tried to make the schematics for it since they don't seem to exist on the web. I was wondering if anybody could verify the schematics I came up with. At some point you are staring at the circuit board for so long figuring out all the connections that a small mistake is easilly made.
These are the schematics I came up with:
(https://i.ibb.co/YfLxGq7/fm-towns-Marty-Tamura-PSU.jpg) (https://ibb.co/2ckTBf7)
Furthermore... I scanned the powerboard (top and bottom) to get the exact dimensions. Those look something like this:
Solder side
(https://i.ibb.co/R447KJ4/Marty-PSU-solder-side.jpg) (https://ibb.co/XkkVPGk)
Component side
(https://i.ibb.co/XCsN5Qt/Marty-PSU-top-side.jpg) (https://ibb.co/Tg8p0ft)
And as last... I am using the dimensions to create a replacement PSU that will work on 230V as well as 110V. I used three power modules to create the 5V, 9V and -9V needed. It will require desoldering of the original AC input, bracket, CN1 and power switch, so that a clean installation is achieved.
This is REV1 of the board:
Top
(https://i.ibb.co/Pr1VrDz/top.jpg) (https://ibb.co/CwVSwPs)
Bottom
(https://i.ibb.co/99CCnT8/bottom.jpg) (https://ibb.co/QF119Nb)
As always... suggestions and corrections are always welcome :-)
This is awesome,
Nice work man!
What's your BOM for one card?
I think there could be a cheaper way to make one of these replacement cards by using 7909 to drop -12V from ITX pico PSU to -9V, 7809 to drop 12V to 9V, right angle 20 pin molex and right angle barrel jack for a power brick. Pull PS_ON line to ground with the switch to power on and off. Don't forget decoupling capacitors for both regulators