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breeze
Account closed
Registered: Mar 2009
Posts: 20 |
C64 & C64C Voltage
One of my good friend requests assistance.
Does anyone know exactly whether there are differences in voltages С64 with C64C? The original power supply is absent. He has made a new power supply and C64C with it works fine.
However, C64 refuses to work with this the power supply. Black screen and sometimes shown white noise. The previous owner assures that the C64 is alive.
Can anybody help? |
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Frantic
Registered: Mar 2003
Posts: 1646 |
I don't know much about this, but sometimes I have came across PSUs that work only for this or that C64, but not for some other, even though yet another PSU work for both. I guess some PSUs are to weak (because they are old) or something like that. Maybe his PSU was not that stable after all? :)
Sometimes it has also happened that a certain C64 + a certain PSU does not work with the wallplugs in a certain apartment, while they work elsewhere (but where a more fresh PSU solves the problem, even in this particular apartment). :) |
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chatGPZ
Registered: Dec 2001
Posts: 11350 |
all c64s run on the same voltages, 5v dc and 9v ac |
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breeze
Account closed
Registered: Mar 2009
Posts: 20 |
Frantic, Groepaz - Thanks, I will transmit to him your words. |
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Devia
Registered: Oct 2004
Posts: 401 |
Quoting Groepazall c64s run on the same voltages, 5v dc and 9v ac
Well, that's not the "whole" truth..
C64c can run perfectly with only 5V, the only stuff NOT working will be Audio output and Tape shit.
Old C64 needs 9VAC to generate 12V DC for VIC/SID.
So in relation to the described symptoms, I'd guess that the 9VAC in the new PSU is either not working or is not able to deliver enough current.
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Mace
Registered: May 2002
Posts: 1799 |
@ Devia: interesting... I never thought of this :-) |
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breeze
Account closed
Registered: Mar 2009
Posts: 20 |
Quoting DeviaSo in relation to the described symptoms, I'd guess that the 9VAC in the new PSU is either not working or is not able to deliver enough current.
Interesting information, but I think that the PSU provides 9VAC and 5VDC. The question is, how powerful must be PSU? Which is load he must withstand?
In the description of the original PSU says 5V-1,7A and 9V~1A, is this enough?
Anybody can measure the exact data from switched-on the Commodore C64?
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Devia
Registered: Oct 2004
Posts: 401 |
Most 9VAC trafos are only 100-200mA which I guess won't quite cut it, but 1A is definately enough. ...and no I don't know any exact numbers, as I never measured it.. |
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Clarence
Registered: Mar 2004
Posts: 121 |
Talking about psu differences, if you take a look at the classic and c64c psu's plug, you'll see that the connected pins are placed differently... |
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ready.
Registered: Feb 2003
Posts: 441 |
After reading the previous posts, the only thing I can think of is that the 9VAC and the 5VDC must have separate grounds. That's why the c64 psu has a double secondary transformer. In fact both secondaries on the original psu have 9VAC output, but they are two separate circuits.
Most probably the c64c can live even if 9VAC and 5VDC are generated by the same circuit, thus using a single secondary transformer.
But the c64 cannot.
I have not tried, so mine are just guesses.
Could you please post a scheme of the psu he made? |
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chatGPZ
Registered: Dec 2001
Posts: 11350 |
the c128 psu i am using is rated 2.5A on 5VDC and 1A on 9VAC ... original c64 psu is slightly less (but if you are planning to use a cartridge, reu or sth like that, you really want a bit of extra juice) |
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breeze
Account closed
Registered: Mar 2009
Posts: 20 |
Quoting ready.After reading the previous posts, the only thing I can think of is that the 9VAC and the 5VDC must have separate grounds.
Hmm ... so it really could be the cause, I will clarify.
Quoting ready.Could you please post a scheme of the psu he made?
OK, I will try to get the scheme. |
