View Full Version : Spectrum 128k +2 (Gray) - 78S05 Power Regulator Replacement

18th February 2015, 22:28
I have a very hot running +2 spectrum, having searched everywhere for a suitable 5v 2a switched regulator without luck would THIS (http://www.ebay.co.uk/itm/1-2-3-5-10PCS-LM2596-DC-DC-Switching-Adjustable-Voltage-Regulator-Buck-Converter-/351085687103?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&var=&hash=item51be56713f) make a good replacement for the original 78S05 regulator?

If it is suitable how would this be connected to the three points of the existing 78S05 (once removed) :help:

Or, can anyone recommend a suitable (UK, in stock) alternative.

Many thanks, -Will

18th February 2015, 22:50
Hi Will

The 78S05 is a 2Amp device so it's very suitable for the Soectrum +2
I would be very hesitant to add a switch mode regulator as it may cause screen interference.


18th February 2015, 23:21
The existing 78S05 is still fully functional... the motherboard has been transplanted in to a small custom case (+2 minus tape deck!) where the original heat-sink wont really fit (although I have taken the hacksaw to it!). This has resulted in alot of heat building up in the case, that's what sent me in search of a replacement. If a switched regulator isn't as good idea (don't want to cause any display issues) it there an alternative, what about a higher rated regulator?

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What about... 78T05 (5v@3 amp output)

19th February 2015, 00:16
just bolt the regulator to a thicker piece of aluminum,job done.

thats what i would do anyway.

19th February 2015, 22:25
I did... but it still gets very toasty...

http://i1342.photobucket.com/albums/o773/williamjohnsteele/AmiBay/th_P1020251_zpsonm08hql.jpg (http://s1342.photobucket.com/user/williamjohnsteele/media/AmiBay/P1020251_zpsonm08hql.jpg.html)