It means: timebase / horizontal set to 10us ( 10 microseconds),
Voltage / vertical set to 2V (volts),
Input channel set to AC coupling,
Synchronisation set to the same channel as the input signal, and set to "TV" mode or "TV Horizontal sync" mode.
None of which will mean much if you have not used an oscilloscope before. Oscilloscopes are complex electronic test equipment. Just like any complex tool, the price goes from cheap for items with limited functionality to very expensive for professional high quality well made gear.
But if you don't have a good quality oscilloscope (or 'scope) or don't have access you one you can use or borrow, don't worry about buying another (better) one yet.
Any of the chips used can be the cause of the fault. Due to the way that a ZX81/TS1000 works, all the chips need to work correctly in order for it to display the normal picture on a TV. I suggested starting off by swapping the ULA chips first because they are the most likely chips to fail, and because they are normally mounted in sockets.ts1000user wrote: ↑Sat May 27, 2017 7:39 amThe working one has Toshiba & Sinclair Research chips and the not working one has NEC & ZCM38818P. Is there any chance that the chips are the reason of this malfunction?
The ZX81/TS1000 are good to use if you want to start to learn to program. They are a proper computer with a CPU, ROM, and RAM. You can start by trying to program using the BASIC programming language. Then if you wish, you can try some simple machine code programming.ts1000user wrote: ↑Sat May 27, 2017 7:39 amI bought it because I want to learn basics of computer structure and machine codes. The Raspberry Pie thing and Arduino thing are all too complicated for me. I first want to understand the very basics of computer structure before dip my foot into the much complicated computer structures.
I saw a modern 8bit Z80A computer kit but TS1000 was cheaper so I bought this one.
However, unless you want to type in your program each time, you also need a device to save the programs that you have written or typed in.
Although the ZX81/TS1000 is a simple computer, under the hood, it operates in a fairly complex way. This is due to there being no special chip to generate the TV picture. Instead the Z80 CPU and the ULA work together (along with the RAM and ROM chips) to draw the TV picture dot by dot.
Mark
Standby alert 
That really helped me to understand about the socketed chips and the oscilloscope a lot. Thanks so much.
