LC III Power Supply Issues

[Byte Knight]

So my TDK 614-0003 power supply in my LC III recently died.  It was making a clicking sound and only putting out a few volts.  After recapping it, it's making good voltage but still making a clicking sound and the voltage goes up and down with these clicks.  Any idea what I should replace next?  I do have the mAcTX LC conversion kit but I was hoping to get the old power supply working to use as a backup.

 

[bibilit]

Maybe ?

 

[Byte Knight]

Maybe ?

The shunt regulator does not appear to be shorted.  Any other suggestions?

 

[bibilit]

Optoisolator or goo

 

[Challenger 1983]

Just to make sure, you are measuring the output when the power supply is connected to the logic board right?

 

[Elfen]

I'm thinking its a logic board or other connected item on the system drawing too much power from the PSU.

Disconnect the fan, hard drive and floppy drive and see if it works without those things. If not, it might be a bad/shorted item on the logic board, usually a cap.

 

[Byte Knight]

I'm thinking its a logic board or other connected item on the system drawing too much power from the PSU.

Disconnect the fan, hard drive and floppy drive and see if it works without those things. If not, it might be a bad/shorted item on the logic board, usually a cap.

It was definitely the power supply.  I did the mAcTX LC conversion with a modern power supply and everything works perfect now.

 

[Elfen]

I have heard of this "PSU Hack" and though I think it is great I'm a bit weary of it. I need to see more of it being used on Dead PSU Systems before I am no longer chicken poop about it...

Glad it works. Congrats.

 

[techknight]

As much as I like those alternative solutions which can be helpful in a pinch, I am a stickler for trying to fix the original stuff and use that. 

 

[Challenger 1983]

I can’t seem to find the aforementioned mAcTX psu adapter anywhere, where could I purchase one, I’m fed up with constantly repairing the stock PSU In my LC III

 

[cheesestraws]

I can’t seem to find the aforementioned mAcTX psu adapter anywhere, where could I purchase one, I’m fed up with constantly repairing the stock PSU In my LC III

I can send you the details of how I built a replacement, but obviously that will come with no warranty at all aside from it worked for me.  Also note that I'm not trying to power a spinning disc from mine.  It's not as good as the macATX but it does work here, at least...

 

[cheesestraws]

I can’t seem to find the aforementioned mAcTX psu adapter anywhere, where could I purchase one, I’m fed up with constantly repairing the stock PSU In my LC III

I've posted details of my bodged one here:





I've had this running stably since ... probably March 24/7, and it's been fine.  I don't have a spinning disc in the machine that I've got on permanently with this in though, so caveat hax0r.

 

[Byte Knight]

As much as I like those alternative solutions which can be helpful in a pinch, I am a stickler for trying to fix the original stuff and use that. 

I'm all for original equipment, but my technical knowledge is limited to recapping, and if that doesn't work I look for a replacement...

 

[Byte Knight]

I can’t seem to find the aforementioned mAcTX psu adapter anywhere, where could I purchase one, I’m fed up with constantly repairing the stock PSU In my LC III

The preorder thread is here, but I don't think he's making any more of them.  You could PM him and see if he's got any extras.