#Sinclair zx spectrum 48k mod
#Sinclair zx spectrum 48k manual
#Sinclair zx spectrum 48k full

A bench power supply was used to check the current drawn by the Spectrum was not too high, which may indicate a fault. It can also cut off the power if the current drawn is too high, which is a useful safety feature when repairing machines. I now have a bench power supply which shows how much current is being drawn by the machine. The lower RAM in the Spectrum has three voltage rails and is easily damaged if one rail is missing.ДЄll these checks passed OK on this machine.

Issues with one can take out the other if power is applied. The above checks suggest that there are no issues with the power supply or RAM. In these checks we measure вЂњapparent resistanceвЂќ to give the machine a rough health check Pre-power checks using a digital multimeter. Here is a link to a webpage where someone has listed the checks from the JoulesPerColomb video which may be of use if you are having a go at this yourself. These checks can highlight faults that if ignored, can cause further damage to the machine.

#Sinclair zx spectrum 48k manual

Pre-Power checksДЄs per the Unofficial Sinclair Spectrum repair manual (I canвЂ™t find this on the internet at the moment), and JoulesPerCoulomb video on YouTube, there are some checks required before you power up a Spectrum. Replace metal faceplate (surrounds the keyboard and has the alternative key legends printed on it)ДЄs usual, I wore an anti-static wrist band thought the repair, to avoid damaging or reducing the lifespan of any ICs.Replace keyboard membrane (the electrical part of the keyboard).Replace rubber key mat (the springy rubber part of the keyboard).Repair any faults found (and there was a major fault discovered).Video transistor replacement (increases image contrast when used with the above mod).

#Sinclair zx spectrum 48k mod

Composite video mod (replaces the noisy RF video output).

Replace 5 Volt regulator (gets hot!) with an efficient DC to DC convertor (doesnвЂ™t get hot).

Replace capacitors (these can go bad over time and cause faults or degrade picture quality).

#Sinclair zx spectrum 48k full

Here is the full list of improvements made to this machine: However, I have since bought a desoldering station which allowed me to go further with this machine as we will see. Much of this restoration is a repeat of my previous video where I restored a pair of Spectrums. There are plenty of machines sold on eBay as вЂњrestoredвЂќ when all they have done is replaced the capacitors and cleaned the front panel, but this Spectrum deserved a good deal more. The machine was in вЂњfairвЂќ condition, showing signs of heavy use (a good thing!) Some of the legends on the keys had also rubbed off. There were some sticky labels (Your Sinclair, a popular Spectrum magazine from back in the day) and the metal plate was pitted as happens with good use. The machine was in a fair state on the outside.