Re: Re: C-64 with no 9v possible failures?
  By: Clocky to Keith Matthews on Thu Nov 05 2015 06:11:35

Hi Again,

 > On 4/11/2015 6:39 PM, Keith Matthews wrote:
 > >    Re: Re: C-64 with no 9v possible failures?
 > >    By: Clocky to Keith Matthews on Wed Nov 04 2015 17:39:04
 > >
 > > Hi Clocky
 > >
 > >   > On 4/11/2015 8:08 AM, Keith Matthews wrote:
 > >   > > Hi All,
 > >   > >
 > >   > > I have a breadbox style C-64 that has stopped working.
 > >   > > I connected my 1501 Power Monitor to the Power Supply and it
 > >   > > seems fine for both 5v and 9v (well it shows 10v)
 > >   > >
 > >   > > The Power Supply work fine with my C64C machine.
 > >   > >
 > >   > > I connect the 1501 Power Monitor to the User Port and I
 > >   > > only get the 5v indication
 > >   > >
 > >   > > There does not seem to be 9v at the user port.
 > >   > > I have pressed in all the chips and checked the internal fuse on the
 > C-64.
 > >   > >
 > >   > > Just wondering if any of you great CBM guru's might know of the top 
 > you
 > >   > > head
 > >   > > what component (I'm guessing a capacitor?) might be failing?
 > >   > >
 > >   > > Also there is no display when powered on. The C-64 Power LED comes o
 > as
 > >   > > Normal.
 > >   > >
 > >   > > Thx for any advice 8-)
 > >   > >
 > >   >
 > >   > Do you know the history of the C64 because the C64 that was sold by Al
 > >   > (but not only Aldi) is known to have the 9VAC missing at the user port
 > >   >
 > > Oh Wow really,
 > >
 > > I just assumed they were all the same. It is a Breakbox (older) model so I
 > > would have expected it to be
 > > Pre Aldi. 8-)
 > >
 > 
 > No the Aldi models where breadboxes but they did have a white keyboard,
 > but that could have been swapped at some stage.

This one has the older style Brown Keys on it. 8-)

 > 
 > > I know the unit used to work, although I could only get B & W out of it.
 > > Prehaps it
 > > is an NTSC version?
 > >
 > 
 > Checking the guts will tell you. Check the part number on the VIC-II and
 > see here;
 > 
 > https://en.wikipedia.org/wiki/MOS_Technology_VIC-II#List_of_VIC-II_versions
 > 

Will Do Thx


 > Since you're in NZ I would suspect it to be the same as our PAL system
 > (in Australia) but I found a 1541 dumped in the bush once that kept
 > popping fuses and it wasn't until I realised it had a 110V sticker on
 > the back that it was an US model. I rewired the 5V and 12V lines to
 > accept an AT power supply and it worked perfectly.

Cool, 8-)


I'm in Australia 8-) Canberra actually. 8-) I thought you were in NZ?

 > 
 > What the hell it was doing laying in the bush I don't know.

Rusting ?  
8-)

 > 
 > > There is no screen now though, so something inside has died.
 > > I wonder where else on the main board I could safely check for 9V?
 > >
 > > Thanks.
 > >
 > 
 > If you are using the old brick style power supply I would recommend that
 > you stop using it as they are notorious for letting go and taking the
 > computer out with it unless you can confirm that it's OK by checking the
 > 9VAC and 5V lines.
 > 
I amusing one of the Black Brick style ones, but it seems to work Fine. I
tested 
it this week on a CBM Power Monitor and it came up OK 8-)

 > There is a fuse inside the C64 that you can check and if you look for
 > the revision motherboard printed on the PCB and post it here (or post
 > pics online of the board) then that will be helpful.
 > 

Yeah I checked the Fuse, it seems fine.

I'll open it up again and have a look at the board version and post it here.

Thanks.
8-)

--------------------------------------
Regards........Geo
oooOOOooo
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