ZX Spectrum +2 repair

[Shock]

Another interesting series, so sharing.

[voltz]

That brought back some memories. Good clear fault finding well explained, quite thorough in his approach.

And using his finger twice, once to detect overheating and another to flex the pcb to locate a problem. We should never underestimate our senses (and fingers) for diagnostic use. Expensive IR camera or finger?... both work to some extent.

Using a single capacitor to delay the rise/fall time of a logic signal, dirty, but seen that used a lot. I seem to remember the LED display on the old Sinclair MK14 had a mod to increase the brightness of the digits by adding small caps to the segment lines to delay the ON time of the scanned display. Happy days..

[Shock]

Yeah the workaround was not perfect, I forget exactly where he was at with that specific timing/noise fault but he was probably a day or more in testing to reproduce it and the alternatives had no guarantees for a lot of extra work. It's normally when people throw their hands up in the air and back away so I guess he deserves the kudos for tackling it.

His other good series if you haven't seen it can be found here:
https://www.eevblog.com/forum/repair/philips-pm3214-oscilloscope-repair/

[obiwanjacobi]

That guy has a lot of other ZX repair videos too. If you like that sort of stuff, it's good info too.
I have seen them all