Full-on black screen, no signs of life. Played it last year showing a friend how silly it is to have a Mulan beat em up and there were zero issues. Did the usual clean the JAMMA edge, double-check voltages, no dice. Haven't dug into it beyond that.
So i found where the screws to open the cart were. System11 kindly showed me where they were. On the two corners opposite the other exposed screws. Have to carefully peel the corners up to reveal them.
Anyway the issue i had with mine where random dots over the screen. It used to go away after 15 minutes but after 2 years it aeems to be more permenent.
What i can judge by the insides is that the pcb takes 5vs and converts it into 3.3v for cmos compatibility. It uses a voltage regulator for this which feeds into various passive components including a 50v 1uf capacitor. If this capacitor goes bad the voltage will drop and you may experience issues. Also near what looks like the gpu asic is another cap. I changed this this and the dots went away.
There are various caps by the sound section but seems to be related only for sound.
Also in the reset and clock circuit there are also smt caps. If these go bad then you will have a dead game.
So to summariese. A dead cart will most likely be either
1. Bad voltage regulator
2. Bad cap by the voltagebregulator
3. Bad cap the reset circuit
4. Bad cap in the clock circuit
5. Lifted pins
6. On some revision motherboards i am told there is a vr pot in the voltage regulation circuit next tonthe regulator. If this goes bad due to anodising oxidation then u will experience problems.
Also thing to note. It seems impossible to remove the mobo without breaking odf the hard to find volume knob. The whole cart is basically a mobo with a rectangular rom board all screwed together to make it look like a giant mvs cart. Smart i thought. Anyway the mobo sits inside the shell flushed but the volume knob sticks out. U either have to bend the shell outwards enough to remove the cart with knob intact (risk cracking the shell) or sacrifice the volume knob. If anyone can find a better way please let me know. I will repost this in the tech section for referencing.
In all circumstances, i highly recommended you open your cart up and replace those caps as they are bad quality and may leak and destroy your game.
Volume knob is similar to a GBA B103 10k pot except that it is 14mm not 16mm. Aliexpress sells 14mm B103s.
Hope this helps
