Papalapa wrote:(..) although I'm not very condifent with my probe.
Just poke it into some other apparatus. There's a cpu in everything
(and clock oscillators that go with it)
The resistor that you mention is R3 that is marked as "not used" in the electronic schemas
No it's not. Afaict from the photo, it's soldered to one side of C6. Other side - not sure... ground? Anyway that's different position than R3. Wouldn't make sense anyway with empty position marked "R3" on the board. Out of curiosity, I checked: all 4 issue 3 boards I have, do NOT have this bodge resistor there. Nor R3 installed.
So it's definitely a bodge of some kind... perhaps some problem with a batch of ULA's, and they added this to the oscillator circuit to fix. I'd consider it tied to the ULA that's in there now: if @ some point you decide to replace it, take that bodge resistor out with it.
'Unfortunately' there's only a few passives there. Ceramic resonators hardly ever die in my experience, unless they're physically damaged (read: visible. Cracked etc). So indeed
mrtinb wrote:Maybe it’s just a broken ULA like 99% of all the repairs in this forum. It seems to be the weak spot.
seems most likely @ this point. It's always possible there's more than 1 problem, but regardless: first things first. No clock -> no go.