@Castellen
measuring continuity is the only way I know how to approach the problem. Yes, it is real time consuming, however I think this machine is worth the effort. As you can tell my electronics knowledge is a little "simplistic" to say the least, however over the years I have managed to repair a multitude of devices with my simplistic knowledge.
I have done things like replace flyback transformers in TV's and Monitors for instance. Recently I had a cap blow in a 17" Monitor which took a string of components out with it when it went, including a chip, transistors and resistors. I managed to repair this, but not by my own fault finding. I found technicians accounts of what had been replaced on the internet, because it was a common problem with that monitor type and I simply ordered all the parts listed and replaced them all and it works. I have built a ton of kits over the years including a SCRAM (SCSI/RAM) interface for the A500 which worked perfectly first time.
So I'm not a complete loon, but I can get out of my depth sometimes, and I think I may be getting there now :lol:
I have also replaced sockets on Amiga Mobo's with success in the past, but I would like to avoid that ATM if I can. There is some quite nasty corrosion in the Denise socket, but I have checked for continuity on the most suspect pin to the underside of the board and to the chips the traces branch off to and it reads fine.
As for removal of the Agnus, well that was just sheer stupidity on my behalf and a small element of impatience. Yes I should have a tool to remove it, but I remembered trying to use one of those in the past (long time ago) and I couldn't seem to get the chip out. Maybe it was a crap tool. My A500 Mobo had some holes beneath the socket which made it quite easy to get it out with a small push from beneath.
I am going to have to invest in some better tools.
The lack of quality gear is also causing me some problems ATM. My good Weller soldering station blew it's heater element and I am currently using a real cheap and nasty iron which has hampered my ability to solder anything. And taken me a lot longer to do things I could do easily with the other iron. For instance putting the legs back on the Agnus took me about an hour to get it right for each of the two chips. I wanted to be sure they were on well enough to not come off when I inserted it into the socket.
I wish I had and knew how to utilise an oscilloscope. I have always been of the understanding that you needed a service manual that outlined what type of signal should be seen on the oscilloscope at certain test points. Guess I should get some rudimentary electronics books and try and up my skills a little. :-D
Checking for suspect traces is hard when the corrosion is masking the area so badly that I'm not sure if there is/was a trace there at all. That is why I have resorted to the schematic to study the RTC area closer and try and make sure I'm not missing anything.
Thanks again for your help and I'll keep you informed on my progress or lack thereof :lol:
