Clicking IIe power supply (no visible damage)

[elemenoh]

I have a IIe that's been operating daily for a month or so without issue. Yesterday, when toggling the power, its power supply made a repetitive clicking noise and would not power up the computer. There was no smoke or smell. I popped the top off the power supply and everything visually looks okay. No signs of leaked or bulging capacitors and the filter caps look okay. They appear to be WIMA, not RIFA for whatever that's worth.

The clicking seems to be coming from the transformer, but it's hard to be sure. Any ideas of where the trouble might be or what/how it should be tested?

If it is the transformer, can you share a link or specs for the needed replacement part?



View attachment IIe-power-supply.mov

 

[bibilit]

Is the psu connected to the Logic board ?

also, what brand is your Psu ? Not familiar to me, but probably because i am used to see the 220 volts units 

 

[elemenoh]

The PSU makes this noise whether or not it's plugged into the logic board.

The marks on it are "Apple Computer Inc. 606-5001 120 VAC 60 Hz, 1 AMP" and "DynaComp, Inc. date code 8533"

 

[bibilit]

Never seen one myself.

Problem is, can be anything, from a failing diode to a cold solder, 

Sounds as the PSU is trying to kick in

 

[omidimo]

I had a similar problem with mine, but I just got it rebuilt: https://www.reactivemicro.com/product-category/power_supply/

 

[elemenoh]

@omidimoWhat made you choose rebuilding your existing PSU rather than getting one of the modern replacements?

 

[omidimo]

@elemenoh The internal were upgraded to the modern board. I wanted to keep the external look original.  I got a complete IIgs setup right at the same time so I have not spent enough time with the IIe. 

 

[waynestewart]

The clicking noise is generally referred to as chirping. Usually it’ll chirp if there’s no load like being unplugged. It’ll also chirp if there’s too much load. That can be because of a short or that the power supply has become so weak that any load is too much for it. Your IIe might startup if you pull all the cards out.

 

[techknight]

It can also do this if the power supply cant go into regulation. Like bad caps, open photo-couplers, etc..