Replaced what I thought was a tantalum but I was wrong. Need help!

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Verault's picture
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Replaced what I thought was a tantalum but I was wrong. Need help!

So let me start off saying I HAD a working  Mac Color Classic. I had already repaired the board and replaced its capacitors last year. This week I was going to finally recap the Analog board. Well once I did theat the unit would not boot and had a constant high pitch chirp. After care ful examinging of the board I found two issues. I replaced a 0.47 100V electrolytic capacitor with a bipolar capacitor of the same value (I installed the correct one). Still a short. I then realized that what I thought was a tantalum capacitor (Judging by its teardrop style package) may not have been a tantalum cap at all. The capacitor CD3 is located at the front of the analog board where the edge connector slided into the chassis, its under the metal shield. 

 

 I desoldered one leg and I can get the analog board to power with no more chirp. 

 

Problem is I threw away the original Cap and finding info online is hard to come by. Can any other Mac color classic owner verify what this cap is at location CD3 on the Analog board?

 

Here is a closeup shot of my analog board with that shield remove and the new capacitor I installed (Like I said I removed one leg to test). What is this capacitor type supposed to be? Tantalums should have a positive designation on the board just like electrolytics and this board doesnt have that. So a typical ceramic?

 

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I can see a '+' right on the

I can see a '+' right on the board at that position. Maybe your replacement is bad or the wrong value?

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Yeah, I would try a different

Yeah, I would try a different cap, could be that one is bad.  Or the wrong value as mentioned.  Bad parts happen.

 

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So I tried another cap, and

So I tried another cap, and replaced a 3300uf cap because it looked a bit cockeyed and the label which shows the negative post location was pretty far from where the pin was and that bothered me (who knows)..

 

Its booting again! I just booted from and external/portable SCSI cdrom (diskman) Which I wanted to test out and it works!.   So I dunno a couple bad caps, and I guess a bad brand new tantalum. Will assemble the whole thing and post back.

 

Phewww! That was nerve racking!

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