Where to start with these?

[kazuo]

I do not have a JVS power supply anymore, would an Astro City PSU be able to provide enough wattage to run model2/model 3?

Probably not, even freshly capped I don't think it would be reliable (or safe) for M2.

M3 wouldn't be possible at all since it needs 3.3V which the stock PSU does not supply.

I would go with an external power supply since you don't have anything that supports JVS.

 

[twistedsymphony]

I don't think it would be reliable (or safe) for M2.

Astro City II was specifically designed for the Model 2 hardware, did it use a different PSU from the normal Astro City?

 

[nem]

Astro City II was specifically designed for the Model 2 hardware, did it use a different PSU from the normal Astro City?

Yeah, it uses this weird double PSU design.

Post in thread 'Sega Astro City 2 Restoration'

Aug 31, 2023

Recap time. First off the Sega 400-5220 power supply.

The Astro City 2 has this special upgraded power supply that in-cooperates two power supplies in one in order to handle the Virtua Fighter PCB stack once again. There is one normal +5V7A-12V1.5A-5V0.1A pcb, and an additional 5V12A board:

What they both have in common were these horrible Marcon caps. I'd say about 60% were leaking horribly. So I recapped it all with 105C 3000h+ caps...

• mourix

• 

 

[crazyjojo]

I've collected dozens of M2 boards over the years, some working, some dead , and I've picked up quite a bit of experience. For basic testing:


1. First, confirm your revision , is it the original version, or A/B/C? From your photo, yours is a Rev A.


2. Power only needs two connectors: CN3 and CN12. Left half is GND, right half is +5V. Both are 10-pin headers, but you only need to connect the outer 3 pins on each.


3. Voltage: most games require a stable 5V ±0.1V, otherwise you'll get a black screen. Keep in mind that aging wiring can cause voltage drop at the endpoint, which can prevent the board from running.


4. Quick fault isolation — problems can occur on any of the three layers: ROM board, CPU board, or GPU board. First, try booting without the ROM board attached. Normally you should see a garbled screen , colored repeating dots. If the screen shows flickering lines or color shifts, the GPU is faulty. If it's a black screen, the CPU is faulty.


5. If CPU + GPU seem fine, plug in the ROM board. The ROM chips are divided into three regions: music, program, and polygon data. Start by testing the middle region (program area). If you get a garbled screen, IC12–15 are completely dead. If you get a solid single-color screen , black, white, green, blue, etc. , then IC4–11 are partially faulty.