marcus77 Posted June 24, 2006 Report Share Posted June 24, 2006 Hi thereHere I am back with some more problems and stupid questions, so excuse me but I want to get my Sid running and all I need to continue is to get the optimized PSU version done.Yesterday I got ambitious and soldered together the whole circuit for the optimized version.I felt really good because it seemed easier than I thought and all in all everything looked nice, logical and it fitted nice in the case.Then the problems started: I started testing with the C64 power supply.First I seemed to have some values but nothing seemed stable.Later on (after thinking about all the things that might have gone wrong),I tested the PSU with a spare C64 and turns out it does not work.Luckily I had a second C64 PSU with which the C64 actually works.Connected again, I got again weird results:The output for the C64Led and the output for the core seemed to deliver something like 2,5V and the 14V did not show anything.Meanwhile I thought about what could be wrong In the realization of the circuit and following things came to my mind:1.The power switch is connected wrongly (tried though different ways but doesn't change things really)2.The connections on the board are done by doing lines with solder.Does this work or should I better take cable?So late yesterday night I checked the forum and this morning I approached it different and measured the C64 Psu output pins.Here again I might do something wrong (sorry I'm a bloody newbie), but If I measure the +5V output (holding one of the testers from the multimeter against PIN2 and against PIN5) I actually get 5,1 V, so this seems to work at least. ;DBut pin 6 and 7 which should both deliver 9V AC don't show anything ???, so those might be broken on the C64 PSU.Tell me how I should measure those because I do not trust my measuring capabilities.So any piece of advise is more than welcome, I could try out different things but I felt it was time to post here because I'm getting more and more confused and didn't wanted to desolder(yet) everything and start again.Sorry again for the noob questions but I appreciate any kind of help.CheersMarc Quote Link to comment Share on other sites More sharing options...
Nattgris Posted June 24, 2006 Report Share Posted June 24, 2006 The 9V AC pins on the C64 PSU is completely separate from the 5V output. That is, they are not referenced to the ground pin as the 5V pin is. To measure the 9V AC you measure between the 9V pins, not between one 9V pin and ground. One tester to pin 6 and the other to pin 7 (not sure about the numbers). Of course you also have to set your multimeter to AC mode (sometimes marked ~) instead of DC mode, otherwise it will read 0V! Quote Link to comment Share on other sites More sharing options...
marcus77 Posted June 24, 2006 Author Report Share Posted June 24, 2006 Hi there and thanks for the help.I checked both PSU's and seems like one is definitely broken and on the other one only the 5V is still alive.It's funny that one Commodore actually still works with the PSU, I guess it just needs the 9V connection for the SID inside, so probably there would be no sound if I try.I bought also a new Multimeter because the other one was actually broken.So I still have actually one mystery,IF my 5V supply works, I should be able to measure it on the outlet of my C64 power socket but it actually doesn't give me anything.At the LED connection and the 5V connection(of the optimized PSUversion) I also get a mysterious 0.40 VDC, is it possible that it comes from the Caps?..and!!.. is it possible to damage the C64 PSU by connecting it to a probably faulty "optimized version" construction?thanks again , I really need the help! Quote Link to comment Share on other sites More sharing options...
Nattgris Posted June 24, 2006 Report Share Posted June 24, 2006 The C64 (at least some models) will still start even if the 9V is missing. If there really is no 9V AC from the PSU it's probably just the fuse that's blown. That could happen if you connect it to a faulty circuit. If you have the dark grey, slanted PSU it's really easy to change the fuse, the holder is located on the back side. There is two, probably only one of them is blown. Probably just as easy if you have the light grey but I don't have one of those so I'm not sure. Check the fuses with your multimeter in ohm mode (should read around zero ohm if it's working). Be sure to replace any broken fuse with one of the same type and rating. The 9V AC supply is simply a transformer and the fuse so there isn't much else that can be broken. Quote Link to comment Share on other sites More sharing options...
marcus77 Posted June 24, 2006 Author Report Share Posted June 24, 2006 Alright, thanks for the useful info, I will try this tomorrow and I'll be back with some new questions if so. Quote Link to comment Share on other sites More sharing options...
marcus77 Posted June 25, 2006 Author Report Share Posted June 25, 2006 Did the test this morning, the 1.6A fuse is definitely broken, so that's where I will have to start, I will also rebuild the optimized version to make sure everything's right.Thanks againMarc Quote Link to comment Share on other sites More sharing options...
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