This is another article on Spectrum power supplies in the PopeyMon Games and Fun series of articles.
In the photo above, there are two different designs of the UK1400 power supply unit (PSU). This was for the 16k and 48k rubber key Spectrums. As described in more detail in Part 1 of the Series and Part 3 of the Series, the UK1400 can also be used on the Spectrum Plus.
In the photo are two similar designs. But they are not identical. Can you spot the differences?
Several other designs also exist, including designs where the transformer is on the top of the PCB, instead of next to it (see photo).
The cases can also differ on the inside, meaning that different designs may not be interchangeable. There are also variations in the capacitors, in the number of capacitors and even the polarity of the wires to the DC cable can be swapped, with respect to the colouring on the wires.
So what seems to be the same PSU from the outside, can be quite different on the inside.
Unless you have owned the PSU ever since buying it, you may not know what has happened to the PSU since it was manufactured. It may have been looked after in the original polys, and lovingly cared for during the last 35 years. Or it may have lived in a damp cellar, being damaged in bad conditions and affected by temperature variations and damp. It may have been dropped from a great height onto a stone floor.
You just don’t know!
And there is also the official Sinclair Safety Warning for one of the designs to consider, as described in this article here.
So using and tinkering with power supplies can put your Spectrum and more importantly, your health and safety, AT RISK!
You should check your power supplier is the right one, and that is safe for you and your Spectrum.
So unless you know what you are doing, please seek professional help.
PopeyMon Games and Fun has refurbished and sold many Spectrum PSUs.
Please get in touch and we can provide a refurbished power supply or repair yours.
There are more types of Spectrum PSU:
- for the Spectrum 128 (Toastrack)
- for the Grey +2
- for the Black +2 (+2A and +2B) and
- for the +3 (and +3B).
Please click on the links for more info on each power supply, and which can be used with each model of Spectrum. The general advice is that as each Spectrum was released, the power requirements increased. So earlier PSUs tend to NOT be compatible with later Spectrum models. In any case, the power connectors changed on the Black +2 and +3.
Thanks for coming to PopeyMon Games and Fun.