Replacement console power supply

[+acadiel]

I had done this a while back - I wanted to replace the brick and internal power supply with a single piece unit.  I found a Meanwell power supply (pictured below) that had all the voltages the console needed - three of them.  At first, I had soldered a DIN connector directly to the underside of the console, but I went ahead this week and took that out and made a proper adapter. 

 

I have pictures of everything color coded and numbered.  The Meanwell power supply has five pins - two are ground, three are the voltages.  I tied the grounds together in the adapter.  To make the adapter, you simply need a female DIN5 connector, some nice gauge wire, and a Molex .156 KK Male header (I used Molex part number WMLX-229 - 4 pin, .156 header 3.96mm).  I put heat shrink around the connectors on one end (I probably should have done both - I just taped the DIN end.)  I simply connected the adapter, routed the DIN connector through the console, and voila.  The internal power switch doesn't function any longer, but you can always add an IEC in line on/off switch.  I think the new power supply is a Meanwell GP25A13A-R1B.  Mine was an older P25A13A-R1B.

 

If someone wants to create a 3D Printed adapter for the DIN5 to fit in the square former power mount in the back of the console, it would make it detachable - I just have not done so.    

 

Anyway, enjoy.

[+arcadeshopper]

Nice I have one as well but haven't done anything with it yet

Lemme know how reliable the console is with that supply

Sent from my LM-G820 using Tapatalk

[+acadiel]

1 hour ago, arcadeshopper said:

Nice I have one as well but haven't done anything with it yet

Lemme know how reliable the console is with that supply

Sent from my LM-G820 using Tapatalk
 

Been running it for a couple years now with zero issues.  No hum either ?

[+dhe]

Come on ArcadeShopper - I'm thinking commercial product here! ?

[matthew180]

2 hours ago, acadiel said:

... I found a Meanwell power supply (pictured below) that had all the voltages the console needed - three of them. ...

The correct voltage are only part of the requirements.  You also have to consider the current for each voltage, and overall power capability.  Looking at the photo of the Meanwell PS you are using, it is probably equal or greater than the 99/4A PS, but you should still know the capability of the PS you are replacing.

 

And to that point, do we know the 99/4A's PS specifications?  I took a quick look at the linear PS schematic that is part of the 99/4A schematic set, and it looks like the -5V is 500mA, the +5V is 1A, and the +12V is 1.2A.  I also think the linear supply was replaced with a switcher at some point?

 

Edit:

The Meanwell PS looks a little low on the +12V and -5V current capability compared to the original 99/4A PS.  But it has +5V current to spare.

 

Edited April 10, 2020 by matthew180

[+acadiel]

1 hour ago, matthew180 said:

The correct voltage are only part of the requirements.  You also have to consider the current for each voltage, and overall power capability.  Looking at the photo of the Meanwell PS you are using, it is probably equal or greater than the 99/4A PS, but you should still know the capability of the PS you are replacing.

 

And to that point, do we know the 99/4A's PS specifications?  I took a quick look at the linear PS schematic that is part of the 99/4A schematic set, and it looks like the -5V is 500mA, the +5V is 1A, and the +12V is 1.2A.  I also think the linear supply was replaced with a switcher at some point?

 

Edit:

The Meanwell PS looks a little low on the +12V and -5V current capability compared to the original 99/4A PS.  But it has +5V current to spare.

 

From what I have measured in the past, the TI drew nowhere near the max current on the native PSU and nowhere near the max capacity of any of the three Meanwell voltages.  It’s been a while, though, since I measured.  I was running with speech, F18, and an Ubergrom running.

 

IMHO, TI over-engineered the linear and switching PSUs.  
 

edit; here ya go:

 

[+helocast]

5 hours ago, acadiel said:

From what I have measured in the past, the TI drew nowhere near the max current on the native PSU and nowhere near the max capacity of any of the three Meanwell voltages.  It’s been a while, though, since I measured.  I was running with speech, F18, and an Ubergrom running.

 

IMHO, TI over-engineered the linear and switching PSUs.  

I'm pretty sure this is what I based mine off of (your 2015/2016 post perhaps?). Good stuff and nice project!

 

I would just caution anybody that doesn't know their way around a multimeter before modding, that I've found several QI motherboards

that don't have their voltages marked correctly. Don't ask me how I know that ? ... it only took finding the first one!

Never found any original motherboards marked incorrectly and that's the majority just about everybody has/comes across.

Now, it isn't a big deal with TI factory power supplies, because they obviously knew and just pinned the molex correctly to compensate.

So, like some errors on the schematics, don't necessarily believe what your eyes are telling you.

 

Doug

[+acadiel]

5 hours ago, helocast said:

I'm pretty sure this is what I based mine off of (your 2015/2016 post perhaps?). Good stuff and nice project!

 

I would just caution anybody that doesn't know their way around a multimeter before modding, that I've found several QI motherboards

that don't have their voltages marked correctly. Don't ask me how I know that ? ... it only took finding the first one!

Never found any original motherboards marked incorrectly and that's the majority just about everybody has/comes across.

Now, it isn't a big deal with TI factory power supplies, because they obviously knew and just pinned the molex correctly to compensate.

So, like some errors on the schematics, don't necessarily believe what your eyes are telling you.

 

Doug

Agreed - mine wasn't marked, so I actually found the ground rail (easy enough) and then measured the voltages on the other pins.  And then numbered both the motherboard and the female molex connector with 1-4 so I could write a small table with which pin was what. When, I coordinated with the five pins on the DIN connector and voila... 

[+acadiel]

For those of you who want to know where I got the internal PSU specs... the RS Archer 277-1016 has them on the back.  (Remember when Radio Shack sold excess keyboards and power supplies?)

 

And also, if anyone is looking for the internal power supply male and female connectors - here ya go.  I remember Tursi had a keyboard adapter that tapped into the internal PSU at one time and there was an issue at the time identifying what worked.

 

[+acadiel]

12 hours ago, dhe said:

Come on ArcadeShopper - I'm thinking commercial product here! ?

If Greg gets a nice 3d printed adapter going that will allow the DIN to fit in the back power space, he can easlily build those adapter cables.  We just need to be completely clear about verifying pinout on them with what's in the console between the regular and QI motherboard revs.  

 

We could also make a dummy PCB with a switch and a triple pole relay in lieu of the adapter (so that the TI power switch could continue to be used)  - I'm pretty confident the relay would allow everything to power on simultaneously, but I haven't done any testing.  I need to find a lower profile triple pole relay first that can handle the current of up to 1.2A.

 

Plug----------->PSU------------->|[Female DIN]----------4pin_board_with switch_and_relay<--------console_psu_connector

 

[Omega-TI]

13 hours ago, dhe said:

Come on ArcadeShopper - I'm thinking commercial product here! ?

That would be nice, if it ever happens, I'll buy one.

A no soldering required kit that allowed use of the stock slide switch hardware would be killer.  

[matthew180]

Meanwell makes a lot of power supplies, many designed to be internal.  I did a quick search and found a few that would probably work internally.  They take a huge range of AC input voltages and frequencies, so they would probably be universal, and would not require a power brick of any kind.

 

The original PS is 4.5" x 4.0" x 1" (tall).  The internal Meanwell I was looking at was 5.0" x 3.0" x 1".  It has an AC input connector, and a +5V, +12V, -5V, and GND output connector.  There is room in the case to possibly make it fit even being half and inch too wide.

 

Anyway, lots of options these days to replace the internal PS.  And if you go by the specs of the Radio Shack replacement PS, clearly the rated outputs are lower than what the components on the PS can handle, so it makes it even easier to find a suitable replacement.

 

21 hours ago, acadiel said:

I was running with speech, F18, and an Ubergrom running.

The F18A uses less power than the original 9918A, FYI.  Can't say what the Ubergrom adds to the requirement.  With the F18A you can also remove the SDRAM ICs from the computer if you want to reduce the power requirements even further.

[Tursi]

11 hours ago, acadiel said:

And also, if anyone is looking for the internal power supply male and female connectors - here ya go.  I remember Tursi had a keyboard adapter that tapped into the internal PSU at one time and there was an issue at the time identifying what worked.

Everything worked.. the only issue I had was the same as Helocast mentioned above - I had a QI machine that was incorrectly labelled on the motherboard.

[Tursi]

26 minutes ago, matthew180 said:

The F18A uses less power than the original 9918A, FYI.  Can't say what the Ubergrom adds to the requirement.  With the F18A you can also remove the SDRAM ICs from the computer if you want to reduce the power requirements even further.

The AVR part of the Ubergrom is rated to draw 12 milliamps. The 49F040 flash chip on the board is rated to draw 50mA.  Neither value include the current drawn by driving the output lines, but that's going to be similar across the board.