Hello guys, I'm kinda new at repairing 8 bit computers 
So last week I got this beautiful Talent DPC-200 MSX as a gift with a two-button Joystick and an untouched Cassete reader (well, not kinda anymore since my bother really wanted to explode these bubbles that we all like exploding 
) along with three game cassettes (PACMAN/GALAGA, PHOENIX and ACTMAN/BRUCE LEE (BRUCE LEE probs not working because my uncle never got it working)). He told me it would be mine if I could repair it.
At first I was like, this is gonna be easy (not forgetting how easy was to fix that famiclone I repaired last year 
)
And the first problem came... I didn't know how the heck open a MSX since it had cables in both sides (up and down, unlike the FC, which didn't have cables attached to the case at all) and I didn't want to break any. Fortunately my Dad came up and helped me open the case withouth breaking the cables.
Not only that, that beast had a complex circut board deticated to deal with the power supply (So not an easy replace-the-capacitor fix like the one I did to the FC). First I tried to aislate the Power Supply from the main board and the case. Had to cut two cables because they were soldered directly to the ON/OFF switch and the switch could only be popped to the outside.
Here was located the power supply:
Now that we have aislated the power supply from everything:
(Note: the photos were taken AFTER removing the heatsink, continue reading)
You might have noticed that from the power supply, we have two sets of cables that go to the main board:
I'm not sure what are I and J but I can confrim that EFGH are the ones that power the main board.
Cables I and J
You can see that those go there:
Cables EFGH
Goes here:
So we had everything set up and the first thing we did try was if the fuse has been blown out. Apparently the fuse was fine.
With the heatsink still in place, we tested the power supply's output through EFGH, by connecting the power and testing the out with a multimeter:
-12 gave -1.2 volts
+12 gave +1.2 volts
+5 gave +0.005 volts
Ok, we have the first hint that the problem resides in the power supply.
We went to try the coil (See image below), specifically the coloured cables.
They returned values similar to the required ones at the power supply's output but in AC
Ok we're fine because that's what a coil does
So I assumed it had to do with something internal, so with the power off (we wouldn't ahve powerd it on without the heatsink anyways), we removed the heatsink (filling our hands with silicone grease) and tested the componets that can be tested without power and for the most part, all the resistor and diodes were fine.
So, it's here where I am at now. Looks like I'll have to put the heatsink again to test out the rest of the components, but my dad says that we could first try to replace the voltage regulators (there's also an huge one, the Saiken STR9005).
So... Will anybody give me a hint? :-?
Kinda new repairing this kind of thing honestly ^^'
Also, might help to let you guys know the transistors:
And some photos of the supply board:
