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Hi just got my hands on a master system 1 but it didnt come with any power supply or controllers and it may need some repair work. Im thinking about getting a mk2 to use as a donor, can anyone tell me

-if the power supply from a mk2 is suitable as a power supply for the mk1

-whether the internal parts of the mk2 can be used in the mk1

any advice gratefully appreciated

Power supply: yes
Internal parts: likely not so much

I wouldn't be as definitive as Maxim regarding internal parts.

Some are the same/interchangeable for/between all Master System consoles (not talking about clones or on-a-chip devices), including but non exhaustive:
- Z80 CPU
- Z80 work RAM
- BIOS ROM (some models are lacking the A14 line, thus need to be hardwired if using a BIOS bigger than 16kB)
- 7805
- Cartridge and controller ports
- Most of the capacitors/resistors

Then depending of the revision of the motherboard:
- VDP (315-5124 or 315-5246)
- I/O chip (315-5216,315-5237 or 315-5297)
- VRAMs (2 x 4168 or 1 x 65256 + 315-5330 custom chip)

If you want to swap chips, some can be swapped. If you thought you might swap the boards then it won’t work.

Regarding the power supply, I would advise against it.
Even though they both use 9-Volts with the same barrel plug and the same polarity (center-negative / sleeve-positive), the MS2 uses a substantially lower-amperage power supply than the MS1.

Seeing as these PSUs are 30-plus years old, ideally, I would suggest getting a new switching unit that is much more stable voltage-wise, resulting in less stress to the also 30-year-old components.

I got a new switching unit for my Master Systems (1&2), Game Gears and Mega Drive 1s (it included a barrel plug adapter to fit either input jack) and although the quality is not the greatest, it still does its' job.

Here's the (now-ended) listing for an idea:
https://www.ebay.com/itm/381906610132?nma=true&si=5LMSh%252FGwk9L6YZBSFSwFSL...

hi all I hope this is the right section, I was looking for help in repairing my sega master system 2 PAL. From the tests I carried out on the board there are 5V on pin 47 IC4 but there is no 5v on pin 46 of IC4. Consequently, the system does not start because it always remains in reset. Anyone have advice on what to check?

Author	Message
lab_rat83 Joined: 12 Feb 2022 Posts: 3	master system 1 & 2 Posted: Sat Feb 12, 2022 1:26 pm
lab_rat83 Joined: 12 Feb 2022 Posts: 3	Hi just got my hands on a master system 1 but it didnt come with any power supply or controllers and it may need some repair work. Im thinking about getting a mk2 to use as a donor, can anyone tell me -if the power supply from a mk2 is suitable as a power supply for the mk1 -whether the internal parts of the mk2 can be used in the mk1 any advice gratefully appreciated

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14738 Location: London	Posted: Sat Feb 12, 2022 1:58 pm
	Power supply: yes Internal parts: likely not so much

Apocalypse Joined: 26 Feb 2021 Posts: 159	Posted: Sun Feb 13, 2022 7:56 am
Apocalypse Joined: 26 Feb 2021 Posts: 159	I wouldn't be as definitive as Maxim regarding internal parts. Some are the same/interchangeable for/between all Master System consoles (not talking about clones or on-a-chip devices), including but non exhaustive: - Z80 CPU - Z80 work RAM - BIOS ROM (some models are lacking the A14 line, thus need to be hardwired if using a BIOS bigger than 16kB) - 7805 - Cartridge and controller ports - Most of the capacitors/resistors Then depending of the revision of the motherboard: - VDP (315-5124 or 315-5246) - I/O chip (315-5216,315-5237 or 315-5297) - VRAMs (2 x 4168 or 1 x 65256 + 315-5330 custom chip)

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14738 Location: London	Posted: Sun Feb 13, 2022 2:01 pm
	If you want to swap chips, some can be swapped. If you thought you might swap the boards then it won’t work.

KeyperOS Joined: 09 Jan 2022 Posts: 22	Posted: Sun Feb 13, 2022 10:57 pm
KeyperOS Joined: 09 Jan 2022 Posts: 22	Regarding the power supply, I would advise against it. Even though they both use 9-Volts with the same barrel plug and the same polarity (center-negative / sleeve-positive), the MS2 uses a substantially lower-amperage power supply than the MS1. Seeing as these PSUs are 30-plus years old, ideally, I would suggest getting a new switching unit that is much more stable voltage-wise, resulting in less stress to the also 30-year-old components. I got a new switching unit for my Master Systems (1&2), Game Gears and Mega Drive 1s (it included a barrel plug adapter to fit either input jack) and although the quality is not the greatest, it still does its' job. Here's the (now-ended) listing for an idea: https://www.ebay.com/itm/381906610132?nma=true&si=5LMSh%252FGwk9L6YZBSFSwFSL...

alexforg Joined: 26 Mar 2022 Posts: 2	Posted: Sun Mar 27, 2022 9:38 am
alexforg Joined: 26 Mar 2022 Posts: 2	hi all I hope this is the right section, I was looking for help in repairing my sega master system 2 PAL. From the tests I carried out on the board there are 5V on pin 47 IC4 but there is no 5v on pin 46 of IC4. Consequently, the system does not start because it always remains in reset. Anyone have advice on what to check?

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