Building a replacement MTX PSU

[wyerd]

I can't make out the wires!

I've magnified the PDF and numbered the terminals:-

[1024MAK]

I can't make out the wires!

In my photos, they are very thin silver coloured wires that come out of the black plastic body of the switch and connect to the terminal very close to the black plastic of the body. Yes, very difficult to see. Your switch may not be the same.

I've magnified the PDF and numbered the terminals:-

Based on this, terminals numbered 1 and 4 are the inputs and terminals 2 and 5 (are your sure this is 5 and not 3?) are the outputs. It does not matter which side is live/line and which is neutral, but both live/line wires need to be on one side of the switch. So I suggest 1 be used for live/line input, 2 be live/line output. 4 would then be neutral input and 5 (3) would be neutral output.

Mark

[wyerd]

OK, thanks. 3 is shown on the rear, together with 6 on the right, but there isn't a terminal in the space.

[1024MAK]

OK, thanks. 3 is shown on the rear, together with 6 on the right, but there isn't a terminal in the space.

Ahh, yes, the plastic body would also be used with DPDT (double pole, double throw) and DPCO (double pole, change-over) type switches which will use six terminals.

Mark

[wyerd]

Thanks for the assistance Mark. Mains side is now wired up and ready to connect to the transformer. Continuity checks out as well this time which alerted me to the wiring issue on the switch.





The switch reminds me of the one on the FDX.

[wyerd]

Mark,

How do you set the output voltage?

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LM2577 step-up DC-DC converter.                             eBay/che'261211800    1 £1.63 £1.63   1     1 LM2577 DC to DC Adjustable Converter Step-up Cir
           I used a Chenyao19870517 LM2577 DC to DC adj                                                                             
           Set the output voltage to 16V before fitting

[1024MAK]

Connect a temporary DC supply to the input terminals. I used a DC power supply set to 8V, but a 9V battery would be fine. If using a PP3 [NEDA 1604, IEC 6F22, MN1604, 6LR61], best use a brand new one.
Connect a digital multimeter to the output terminals.
Now locate the preset (variable resistor) on the board. On mine, it is a square blue coloured item, with a small gold adjusting screw. Turn the screw until the meter indicates between 16V and 16.1V. Note that the preset is a multi turn type, so don't worry if you have to keep turning it. The value of 16V is nowhere near the end stop.

Disconnect, and install. Job done

Mark

[wyerd]

Connected it to a 9v battery. Adjusted the screw until mulimeter read 16v. Job done!

[wyerd]

Mark,

Can you confirm the ouput connections of F2 please?

Red connection to DIN Plug 3
Black connection to DIN Plug 4
Black connection to R2 of LED
Black connection to black output of strip board - This is the connection I can't see in the photos.

Thanks.

[1024MAK]

Mark,

Can you confirm the ouput connections of F2 please?

Red connection to DIN Plug 3
Black connection to DIN Plug 4
Black connection to R2 of LED
Black connection to black output of strip board - This is the connection I can't see in the photos.

Thanks.

Yes, what you have listed is correct. On the strip board, the black wire from the fuse goes to the "0V" track. This track is the one that is the negative connections for the two capacitors. And another black wire goes from this track to the -V input of the DC-DC converter board.

I hope that helps

Mark