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Power Supply 110V plugged into 220 v mains. Magic smoke came out. :(

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fjk61011

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You might be okay by replacing the caps, but check the diodes and the inverter transistors as well. Hopefully, you damaged only the primary (AC line) side of the supply.
 
Check the fuse. Usually a diode or the transistor will die first to try and save the fuse. Sometimes it doesn't work that way.
Also don't under voltage supply. The early ones don't have any brownout protection. If your line voltage is normally low, either use a variac or a boost transformer.
Running with the voltage to low can cause the switching dwell time go to zero. This causes the transistor to over current and poof.
Dwight
 
Dwight Elvey said:
Check the fuse. Usually a diode or the transistor will die first to try and save the fuse. Sometimes it doesn't work that way.
Also don't under voltage supply. The early ones don't have any brownout protection. If your line voltage is normally low, either use a variac or a boost transformer.
Running with the voltage to low can cause the switching dwell time go to zero. This causes the transistor to over current and poof.
Dwight
Click to expand...

Our national grid is quite robust, no brown outs.

I have 220 to 110 step down transformer that I'll use until I make the mod.
 
Generally , wired in the 230V mode, the input rectifier and filter system is wired as a full wave bridge rectifier (4 diodes) to charge the capacitor pair, but in 115V mode, it's wired (or switched if that option is there) into a half wave voltage doubler and for this only two rectifiers (not 4) are used.

In both cases if all is well just over 300V DC is available. Of course if it's fed with 230v, when in 115V mode the capacitors will be well over voltaged, start to draw current and gas out, explaining why they burst. It is possible the chopper (inverter) transistors are still ok, you could initially just in circuit test them for shorts. And as noted check the rectifiers.

It's awkward in Australia having a lot of dedicated 110V gear in my workshop with standard IEC connectors and 230V power here. On the equipment, I have to be very careful what I plug into where in the workshop where I have both 110(from step down transformers) & 230V power points.
 
Hugo Holden said:
Generally , wired in the 230V mode, the input rectifier and filter system is wired as a full wave bridge rectifier (4 diodes) to charge the capacitor pair, but in 115V mode, it's wired (or switched if that option is there) into a half wave voltage doubler and for this only two rectifiers (not 4) are used.

In both cases if all is well just over 300V DC is available. Of course if it's fed with 230v, when in 115V mode the capacitors will be well over voltaged, start to draw current and gas out, explaining why they burst. It is possible the chopper (inverter) transistors are still ok, you could initially just in circuit test them for shorts. And as noted check the rectifiers.

It's awkward in Australia having a lot of dedicated 110V gear in my workshop with standard IEC connectors and 230V power here. On the equipment, I have to be very careful what I plug into where in the workshop where I have both 110(from step down transformers) & 230V power points.
Click to expand...

I'm in a home situation. 220V AC in all the sockets. The psu was 110v in, no switch to take 220V. I'll do a little checking tomorrow.
 
If you can find a big split-primary transformer (one with 120V/240V windings, hooked in series or parallel), you can configure just the primary side as a autotransformer; i.e. hook the windings in series for 220/240v as normal, but take the 120V from the center tap and the low end (neutral) of the AC feed. Not an isolating situation, but easily sourced.

If you're in 120V land and need to run 240V equipment, you can use the same setup; just feed 120V to the center of the two windings and take your 240V from the top and bottom ends.

xt4rzoi.jpg
 
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Chuck(G) said:
If you can find a big split-primary transformer (one with 120V/240V windings, hooked in series or parallel), you can configure just the primary side as a autotransformer; i.e. hook the windings in series for 220/240v as normal, but take the 120V from the center tap and the low end (neutral) of the AC feed. Not an isolating situation, but easily sourced.

If you're in 120V land and need to run 240V equipment, you can use the same setup; just feed 120V to the center of the two windings and take your 240V from the top and bottom ends.

xt4rzoi.jpg
Click to expand...

I have a Step-down 220 VAC to 110 VAC external transformer. I'll use this with the 110 VAC power supply.

I have the following:

130 W 220 VAC PSU, working. The fan is unreliable. It is rivited to the case cover. :( I used the case cover with a new quiet fan from the damaged psu. Only some screw holes line up. It is now in the 5150 and working fine. Labeled 220 VAC 130 W.

130 W 110 VAC PSU working. Tested this with the external transformer and it works. Problem: The screws of the new fan are a tiny bit too big for the holes in the case. Drilling required.

130 W 110VAC PSU, damaged. I may or may not try to repair this and convert this to 220 VAC at the same time. I'm not sure how to test with components in the circuit.
 
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OK, I was able to get the AC fan off the original cover of the 220 VAC supply. New fan and cover in.

I'm getting a 201 error now on that PC.

EDIT: I seemed to have changed the DIP switches while I was plugging in the floppy drive. Reset them and booted. Error gone, PC working.
 
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Two 130 W power supplies in two 5150s. With new 12 V DC quiet fans.

I think I'll tackle glitch's XT-IDE Rev 4 kit which I forgot I had.
 
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