The Sinclair QL Forum

I think the wave forms and voltages may not read well on a multimeter. A scope will be the best way to read these voltages - assuming your probes and or scope inputs have the correct rating to check these - as you are dealing with quite high voltages here!

Yes - provided the main capacitor on the primary side is ok, and the bridge rectifier - you should see the full wave voltage from the mains across it - so it will around 380-400v - for a 230/240 V mains supply. It's not that critical as the power supply works down to 110V by the looks of it. The cap...

Looks like the 12V output from the PSU is used to regulate the PSU primary circuit, and the 5V circuit is further regulated by another IC, and also has a crowbar circuit across the input to that IC. Full service manual here: https://elektrotanya.com/grundig_gv280s-vpt,ft,t_vcr_sm.pdf/download.html#dl

Do you have the service manual for it? Those circled numbers probably have expected waveforms or voltages to measure on the primary side, so if they are ok, the issue is likely on the secondary side of it. It's rare but not impossible for rectifiers on the secondary side to fail, which will obviousl...

Back then Video hadn't even been born, so the Radio star was safe

Happy Birthday - enjoy the vino

To be fair to them - I've had something stuck at "langley" and it was down to customs check delays - so although it appeared to indicate RM had my parcel - it had not been officially released to them. I hate the fact that the tracking from either side doesn't tell you what our lovely HMRC ...

esp32_ser.jpgHey Pr0f ; Someone was way ahead of me :D Anyway its great to try to program such nice connection. And one can make your own preferences. I do like the lilygo products though - and there is probably a lot more this could potentially offer - would be interesting to see how well it works...

I wonder if those serial network modems would provide time?

https://www.simulant.uk/shop/retro-vint ... compatible

The other approach would be to use an RTC chip that actually does have a "seconds counter" and just disable the ZX8302 whenever a read access to those RTC addresses is made - and provide the data from the seconds counter RTC chip instead. No I2C needed - as the code in the QL is already se...