viasho VD-IIIA driver

[polishedball]

Has anyone ever had one of these drivers in my case for a 500mw 532 fail where it just power cycles it self off/on/off/on ? I don;t belive it is a head issue as it does the same thing with the head disconnected unless that is how they act when the head fails. Trying to determine how to handle the mess and would you know it 2 weeks from SELEM, starting to wonder if its another sign i shouldn't pursue making the trip.

[DZ]

You sure the problem is with the driver? What you describe sounds exactly like the common failure of a switching power supply. Do you have another power supply to try?

Or is this driver an all in one style setup? Driver and power supply in one nice box and you just connect AC? If so, it still sounds like the switching power supply failed. Might be an easy way to replace it. Never messed with a viasho driver, if it just takes 5V DC, do you have a 5V supply laying around?

[polishedball]

It uses this Mess

[DZ]

Ok, have you taken the cover off? If it's still under warranty, that might not be a good idea. If not, inside I would expect to see a driver and switching supply. Disconnect the driver from the switching supply and measure the voltage from the switcher, I suspect it will continue to pulse. You might be able to find some info for the switcher (IE-voltage output or model number info). I may have a 5V 7A switcher somewhere at home I can bring to SELEM.

[polishedball]

It looks like the driver uses +/- 12v and 5V. The driver board is feed from a switching supply below it with those voltages. Can I just use an atx power supply to replace this wire it in for the voltages and see if it works? yellow +12 Blue -12 and red +5?

Know of any small switching units to replace it with if needed?


John

[polishedball]

Just verified with a meter, the voltages go from good to bad after it is on about 2 seconds. None of the caps look bad of course it couldn;t be that easy. bring back linear supplies I SAY!!! those make sense to fix. The voltage input is at the top of this board.

[DZ]

Hmm, I wonder why they have +/-12V. The only problem I see with using an ATX power supply is current draw. If I'm not mistaken, isn't the current output of an ATX supply rather low for -12V? It may be fine for the driver, just no idea how much current it needs for -12V. So I'm guessing the switcher is all one board and not 2 seperate supplies? Are all the outputs pulsing? If it's all one package, I'm sure you can find a replacement from Jameco, if the ATX supply doesn't work.

[polishedball]

Thanks it did turn out to just be the PS, working again but now I need to find the right fix.

[DZ]

Sweeeeet!

[polishedball]

Hmm, I wonder why they have +/-12V. The only problem I see with using an ATX power supply is current draw. If I'm not mistaken, isn't the current output of an ATX supply rather low for -12V? It may be fine for the driver, just no idea how much current it needs for -12V. So I'm guessing the switcher is all one board and not 2 seperate supplies? Are all the outputs pulsing? If it's all one package, I'm sure you can find a replacement from Jameco, if the ATX supply doesn't work.

Yes all voltages were pulsing, the -12 is low on an ATX only .5amps. But at least now I know I don;t have bigger issues. Thanks for the idea!