Denial

I've acquired another power supply for an original VIC, it had a faulty fuse but other than that it seems to be working. What is the correct rating for the fuse? It's a 1001038-04 (240V primary), my other PSU had a 200mA fuse, but I blew that while testing

My powers of observation are particularly poor today: it clearly has "T200mA" written on the side...

remember that "T" means "timed" (slow blow) because powering it on there are a natural peak of current (transformer magnetic field and filter capacitors charging),
so you have to put a "T" type or fuse could blow during a switching on...

Hijacking the thread to ask about peak current in a switched PSU. I have this new PSU with a power switch. Should I keep the VIC on and use the PSU switch to power it on, or is it advisable to turn on the PSU, then the VIC to avoid the VIC receiving peak current? Thanks.

inside PSU there are some components that have to store energy, at powering on this empty components have to be filled of energy to reach the normal working level, in this moment a current peak is reached ONLY onto 220V line (the line protected by fuse...).
No strange voltages outputted by PUS (rising voltage from 0V to Vcc is rapid and certainly covered by the RESET signal/procedure).

So I assume I can use only the power supply on/off switch with my VIC or C64 always on? Did I understand correctly?

Could replacing the psu fuse with a newer one help prevent psu blow out on the vic?

srowe wrote:I've acquired another power supply for an original VIC, it had a faulty fuse but other than that it seems to be working. What is the correct rating for the fuse? It's a 1001038-04 (240V primary), my other PSU had a 200mA fuse, but I blew that while testing

It should be ok with a slow 200mA fuse at up to 240V. If it blows after some time, the PSU is probably starting to pull too much current through some of its capacitors, or it could be that the Vic-20 is causing that. Have you changed the fuse and tried it with another Vic-20? Changing capacitors in the PSU or Vic-20 might be necessary, so I would start by checking those.

Kakemoms wrote:

srowe wrote:I've acquired another power supply for an original VIC, it had a faulty fuse but other than that it seems to be working. What is the correct rating for the fuse? It's a 1001038-04 (240V primary), my other PSU had a 200mA fuse, but I blew that while testing

It should be ok with a slow 200mA fuse at up to 240V. If it blows after some time, the PSU is probably starting to pull too much current through some of its capacitors, or it could be that the Vic-20 is causing that. Have you changed the fuse and tried it with another Vic-20? Changing capacitors in the PSU or Vic-20 might be necessary, so I would start by checking those.

Experiencing no issues. I'm just concerned about the issue of the vic psu being a "ticking time bomb"

I have seen replacement psu for the cr models but no alternatives for the 2 pin.

R'zo wrote:Experiencing no issues. I'm just concerned about the issue of the vic psu being a "ticking time bomb"

I have seen replacement psu for the cr models but no alternatives for the 2 pin.

Ok. Well, you need at least 3Amp at 9V AC which is not so easy to get hold of. I have seen both 1Amp and 2Amp on ebay, but no 3Amp. There is a 12V AC 3Amp there though, but 12V might be a little too much?

Edit: Actually, it seems like one of the original supplies were at 11.5Volt (from wiki):

Part No. 902502-02 (early version)
(identical in appearance to 902502-01. Small, stepped, black moulded plastic cube.)
110V, 60Hz for N. American / Japanese market
Openable: NO
Replacable fuse: NO
Input: 117V, 60Hz, 400MA
Output: 11.5VAC, 30VA

Kakemoms wrote: It should be ok with a slow 200mA fuse at up to 240V. If it blows after some time, the PSU is probably starting to pull too much current through some of its capacitors, or it could be that the Vic-20 is causing that. Have you changed the fuse and tried it with another Vic-20? Changing capacitors in the PSU or Vic-20 might be necessary, so I would start by checking those.

I was fiddling about and loaded the fuse carrier while the transformer was plugged in. I only have 2A fuses to hand, both transformers seem to be working now. I've ordered some replacement fuses of the correct rating, I probably won't use the VIC much until they come.

In the case of the 2 pin VIC, the external brick is just a transformer (with approx 12VAC secondary). The rest of the linear DC power supply (rectifier, smoothing caps) is inside the VIC-20.

Generally with power supplies, it is capacitors that go bad. For the two prong VIC, these components are within the VIC-20 itself. The transformer is a pretty reliable component in general and is unlikely to fail in any way that gives overvoltage at the output.

Any life-extension for the two prong VIC is going to involve replacing the power supply capacitors (and maybe the rectifier) inside the VIC. (Or just bypass the whole lot and use an off-the-shelf external DC supply connected to the output of the built-in power supply circuit?)

I've considered replacing the capacitor in my two prong VIC but it seems hard to find new axial caps of the right value. Most I can find are NOS so there's a risk I'll be no better off than keeping the current one.

NOS should be better - what makes the caps go bad is heat (usually produced by something else in the PSU - which is why its bad design to place them near the components that produce lots of heat)

There is a good selection of axial capacitors here at Jameco Electronics : http://www.jameco.com/shop/keyword=axial-capacitors