🇬🇧 Grundy NewBrain: Part 3 (Troubleshooting begins) [TCE скачать в хорошем качестве

🇬🇧 Grundy NewBrain: Part 3 (Troubleshooting begins) [TCE

Managed to get it to boot finally. The 10µF electrolytics on the reset & powerup lines were a bit dodgy (measured at 6.6µF when removed and some corrosion around them), and measuring the pins on IC452 showed they never came to 5V. Replaced both and it then booted! But garbage on the screen and VFD. So perhaps a RAM issue? Measuring the input voltages show 7V (and not 5V), 13.5V (and not 12V) and -5.5V (probably okay), so perhaps an issue there with the voltages. There are a few other electrolytics on the board that look suspect (corrosion on surrounding components) so am replacing them one-by-one. Parts replaced this session: Motherboard: C6: 22µF 35V C7: 47µF 16V IC40: LM358P socketed C125: 10µF 25V C127: 10µF 25V RAM board: C27: 10µF 25V C28: 10µF 25V C45: 10µF 25V To be continued! Oh, I should also note what revision boards I have: Motherboard: NB12117/*/7 RAM board: NB12118/*/8 Keyboard: NB12125/*/3 Thanks to ‪@thomasgutmeier367‬'s troubleshooting tips here: http://www.8bit-homecomputermuseum.at... http://www.8bit-homecomputermuseum.at...