PSU dummy Load resistors

[Marcopolomint1]

On the STE PSU connector there are 2x 5v lines, 3x earth and 1x12v.

1. I assume the 3 ground are common so it doesn't matter which one you connect one end of the resistor to?
2. is there a specific 5v line of the 2 on the connector you should connect the other end of the resistor to?
3. I take it you just solder on header pins to the resistor tails and plug the headers into the connector?
4. Both resistors must be connected at power on?

Thanks,

Marco.

[exxos]

Any red to any black 3R.

Blue to any black , 22 R.

Technically you only need to load the 5V (red) for the PSU to work. But its better to test under fuller load for 30 seconds on both to make sure PSU is stable.

[Marcopolomint1]

Many thanks. Will report back this weekend on repair/results, fingers crossed.

[Marcopolomint1]

Hi, Ok got the capacitor kit, transistor, rectifier and 2x resistors (R201,R202) all fitted perfectly. Load resistors connected (max 15-20secs at a time). All very neatly done.

Initially 5v = 5.39v
12v = 11.90v

However if I set the trimmer pot to output 5.00v, the 12v line drops to 11.20v....

So should I bias the 5v closer to 5.00v or bias the 12v closer to 12.00v?

I see this statement by you also Exxos also...""Though without this new PSU mods, those lines start flickering pretty bad. This STE seems to run happiest at 5.25V. Any lower and the video noise issues start coming back. Overall the peak power can be improved with just a couple resistors and a new capacitor

Thanks.

[exxos]

If this is an STE there is other mods to do yes..https://www.exxosforum.co.uk/atari/last ... /index.htm

The 12V is always low. Nothing much uses it, on the STE some stuff has a 9V regulator, can't remember. So even 11V is fine anyway. The PSU's have no regulation on the 12V at all. "cheap and cheerful" cost cutting really.

[Marcopolomint1]

Interesting enough I have absolutely zero ghosting on my STE.

But regarding the 5.00v line what do you think is best....the better behaved 5.25v as per your STE comment or around this or just
go for the nominal 5.00v?

cheers,

Marco.

[exxos]

But regarding the 5.00v line what do you think is best....the better behaved 5.25v as per your STE comment or around this or just
go for the nominal 5.00v?

As general advice I would just set it at 5.00V , most Atari PSU's are lower voltage than that anyway.

The more official standard is your supposed to set it up more like "5.10V".

The proper way, is to measure the voltage furthest away from the power supply and make sure that is 5.00V. so your PSU may well be set to 5.25V to get 5.00V near the ACIA for example.

As to what works best voltage wise, its completely dependent on the STE itself and its impossible to answer without personal trial and error. Some machines work better on a slightly higher voltage and others on the slightly lower voltage. It really depends how stable they are.. Which generally isn't very !