BBC Model B No2. Will it live again!

[PaulJ]

I'm not allowed superglue and my soldering iron time is limited, due to the burnings.......

:dizzy:

Jon, you should be careful.... had a friend that had property adjoining a forest area where there were a lot of fallen dead tree's. He enjoyed taking his chainsaw out and cleaning out the downed dead tree's. One tree he was cutting unknown to him was under a load and when cut the base it snapped forward and smashed his face... nose was really flat and there was blood everywhere. After a trip to the emergency room his wife took his chainsaw away from him and gave it away. I'm surprised your wife still allows you to operate a soldering iron. :comp:

[rubber_jonnie]

I'm not allowed superglue and my soldering iron time is limited, due to the burnings.......

:dizzy:

Jon, you should be careful.... had a friend that had property adjoining a forest area where there were a lot of fallen dead tree's. He enjoyed taking his chainsaw out and cleaning out the downed dead tree's. One tree he was cutting unknown to him was under a load and when cut the base it snapped forward and smashed his face... nose was really flat and there was blood everywhere. After a trip to the emergency room his wife took his chainsaw away from him and gave it away. I'm surprised your wife still allows you to operate a soldering iron. :comp:

Sounds painful!!! Hope he recovered ok.

I've been better with the soldering iron of late, so not had any irons confiscated of late :)

[PaulJ]

I've been better with the soldering iron of late, so not had any irons confiscated of late :)

Jon, he got over it but still misses his chainsaw. You have been burn free because your iron has been locked up in storage so I wouldn't go crazy taking credit until you and that pesky iron have lived in the same house without incident for a number of months.

[rubber_jonnie]

I've been better with the soldering iron of late, so not had any irons confiscated of late :)

Jon, he got over it but still misses his chainsaw. You have been burn free because your iron has been locked up in storage so I wouldn't go crazy taking credit until you and that pesky iron have lived in the same house without incident for a number of months.

Ah ha, but I do have a temporary Iron!!

I should make a sign saying how many burn free days I've had :)

[PaulJ]

Thats a great idea Jon.. then your wife can check the number and if lower that say 90 lock that pesky ole iron up. :mrgreen: :mrgreen: :mrgreen:

[rubber_jonnie]

Thats a great idea Jon.. then your wife can check the number and if lower that say 90 lock that pesky ole iron up. :mrgreen: :mrgreen: :mrgreen:

That's it, I'm going to get one sorted once I'm into the new workshop!!

[rubber_jonnie]

So, next steps once the parts arrive will be:

Remove the two caps from the 16Mhz oscillator circuit.
Remove the 16Mhz crystal.
Check that the continuity is good between all points in the socket and oscillator circuit and to all the other points that it feeds on the board.
Fit new components.
Check continuity again.
See what's what.

If still no good, I'll need to try and figure out my next move.

Also still trying to buy another working one for comparisons sake.

[PaulJ]

So, next steps once the parts arrive will be:
Remove the two caps from the 16Mhz oscillator circuit.
Remove the 16Mhz crystal.
Check that the continuity is good between all points in the socket and oscillator circuit and to all the other points that it feeds on the board.
Fit new components.
Check continuity again.

Jon, I don't know if your scope is in storage but I would use a scope prior to using an ohm meter. If the signal your locking for is missing then get the meter out. A lot of times its not a missing signal issue but a mal formed signal. Anyway just a thought if you have your scope available.

[rubber_jonnie]

So, next steps once the parts arrive will be:
Remove the two caps from the 16Mhz oscillator circuit.
Remove the 16Mhz crystal.
Check that the continuity is good between all points in the socket and oscillator circuit and to all the other points that it feeds on the board.
Fit new components.
Check continuity again.

Jon, I don't know if your scope is in storage but I would use a scope prior to using an ohm meter. If the signal your locking for is missing then get the meter out. A lot of times its not a missing signal issue but a mal formed signal. Anyway just a thought if you have your scope available.

I have only a basic scope, my main one is in storage.

I am also concerned about the signals being malformed, but with the super basic scope I have available, it's pretty hard to tell, so things kind of look right, but I'm not 100% convinced.

I'm checking continuity purely and simply because I want to know all the points are connected to where they should be as I see evidence of rework other than mine.

What's interesting is that last night the method I'd used to trigger the oscillator stopped working, which suggests either the 74S04 that I replaced has died, so I have more on the way, or the oscillator itself has failed, for which I have new caps and crystal on the way.

Fingers crossed over the weekend the rest of the parts will turn up, though I have my 2nd vaccination on Sunday, and if the first was anything to go by, I won't feel too good afterwards for some time, so I'm hoping the parts arrive tomorrow.

[stephen_usher]

Where are you getting the parts from? They're taking an awfully long time.