Chapter marks and then full description below ...

00:25 ... "40 Best Machine Code Routines for the ZX Spectrum" Kickstarter book
01:10 ... first look at the keyboard & case
05:00 ... opening it up
11:05 ... ZX Interface 1
11:20 ... AC power supply
12:30 ... removing keyboard from case
17:00 ... "The ZX Spectrum ULA" book
21:15 ... different ULA versions
22:38 ... nice thankyou card from St. Wilfrid's Hospice (refer earlier rambling about a Spectrum+)
24:10 ... back to the Speccy board
25:00 ... composite video mod. starts
29:00 ... RF modulator can is removed from board
31:20 ... composite mod. completed
32:33 ... first poweron test
33:20 ... testing with a keyboard (TS1500)
36:30 ... checking heat with thermal imager
38:30 ... replacing 7805 linear regulator
39:10 ... board closeup
41:40 ... opening up the ZX Interface 1

I don't think I've ever done a video on an original/genuine Sinclair ZX Spectrum ... I've got a Spectrum +2, a Timex Sinclair TS2068 and loads of Soviet/postSoviet clones, but this is my first genuine 48KByte Speccy. This one is an Issue 2 board.

{Updated as per @1337Shockwav3's comment, thanks}
I thought it might be a little more interesting to look at one that came in an aftermarket case by Fuller ... the "Fuller Desktop System" or FDS. In this, ahem, "case" it has been modified on the back to accomodate the ZX Interface 1 expansion.

{Corrected as per @markevans2294's comment, thanks}
It also comes with a "ZX Interface 1" that provides MicroDrive, RS232 serial and "ZX network" interfaces.

I'm planning to replace the original ULA (6C001E6) with vRetroDesign's vLA82 with RGB output, so to test if the machine is working I did the simple composite modification ... well, I stripped out the contents of the RF modulator can and installed a 100µF electrolytic capacitor.

And it seems to be working. I used the keyboard for a TS1500 to test it a little further (the case & keyboard were still drying from their beauty treatments).

I replaced the 7805 linear regulator with a PSU25 from EZSBC.

To be continued.

Relevant links (not sponsored):

"40 Best Machine Code Routines" book:
https://www.hueygames.com/40bmcrzx...

Tynemouth Software's always excellent repair blog (Dave):
http://blog.tynemouthsoftware.co.uk/2...

Composite modification:
https://spectrumforeveryone.com/techn...

vRetro for replacement ULAs & other goodies (Charlie):
https://www.vretrodesign.com

EzSBC for replacement regulators (Daniel):
https://www.ezsbc.com