Well good news and bad news...mainly bad ![:lol:]( "Laughing")
I gave it another whirl this morning and Pin 1 was 14v up until I asked the beeb to program and then once it started programming it dropped to 3v again. But turning the programmer off and back on resulted in the voltage going back up to 14v. So it seemed having the eprom in made no difference to the voltage it's just when the beeb starts to do the programming it drops (rather than just flicking the programming switch)...i.e. programming switch on = 14v but programming switch on and beeb programming = 3v.
Any who I then started the testing of the 7812 pins which were 14v and ~49v (but this is where I saw a little spark as my multimeter prong had shorted out the 7812). It was then 52v on either pin...so I desoldered it and put in a new one (good job it was a 5x pack!).
Now it's really unhappy, when the Beeb is programming it it's dropping to 3v still and without the beeb programming it:
..............No EPROM.....EPROM Inserted
Pin 1.............6.3v..............6.1v
Left Leg........52.5v............52.4v
Right Leg........6.3v.............6.0v
With the programming switch off pin 1 is 5v.
On the positive side the pot now does do something as the voltage ranges from 4.6v - 6.3v. The 7812's I'm using are 7812cv is the cv of significance?
I gave it another whirl this morning and Pin 1 was 14v up until I asked the beeb to program and then once it started programming it dropped to 3v again. But turning the programmer off and back on resulted in the voltage going back up to 14v. So it seemed having the eprom in made no difference to the voltage it's just when the beeb starts to do the programming it drops (rather than just flicking the programming switch)...i.e. programming switch on = 14v but programming switch on and beeb programming = 3v.
Any who I then started the testing of the 7812 pins which were 14v and ~49v (but this is where I saw a little spark as my multimeter prong had shorted out the 7812). It was then 52v on either pin...so I desoldered it and put in a new one (good job it was a 5x pack!).
Now it's really unhappy, when the Beeb is programming it it's dropping to 3v still and without the beeb programming it:
..............No EPROM.....EPROM Inserted
Pin 1.............6.3v..............6.1v
Left Leg........52.5v............52.4v
Right Leg........6.3v.............6.0v
With the programming switch off pin 1 is 5v.
On the positive side the pot now does do something as the voltage ranges from 4.6v - 6.3v. The 7812's I'm using are 7812cv is the cv of significance?
Statistics: Posted by vela025 — Sat Dec 21, 2024 11:29 am