Dim Drive Light

[Super TWiT]

I tested again and this time there was a louder noise than before. I KNOW nothing shorted this tims because I had some help holding the connector this time. I noticed a volt reading didn't register but that might be because it was only on a fraction of a second. So, maybe its time for the local electronics repair guy to take a look at this. There is a shop down the street. Where you serious about not plugging it into the amiga or was that where the lmao comes into play, because that would validate basic psu function.

[save2600]

Do not plug that into your amiga! Power supplies are not supposed to hum, vibrate or whine loudly normally. That indicates something is wrong. Keep it turned on and keep the leads on the pins to ensure voltage is correct or not.

You know... if you swear you didn't short it, you know what? I bet that power supply just happened to take a dump on you and coincidentally, did it while it was not plugged into the machine. Fuses don't always blow and power supplies can and do (often) leak wrong current out of 'em when they fail.

I bet it's bad and you can count your blessings it didn't take your Miggy with it.    The dim drive light was a pretty good indication a component was starting to fail. It's all diodes and caps now buddy!  lol

[Super TWiT]

Maybe its not my fault then. The first time, maybe it shorted but I didn't think so. The second time definitely not. There's an electronic repair shop down the street. Maybe I should have the look at it.

[save2600]

So, the whining doesn't mean its going to blow up and kill me?

LOL! Nah.

[Super TWiT]

There is an electronics shop down the street. They look like they repair pretty much anything. Should I take the psu down to him and have him look at it. I really feel like I shouldn't look inside a psu without knowing anything. I am a software guy!

[save2600]

There is an electronics shop down the street. They look like they repair pretty much anything. Should I take the psu down to him and have him look at it. I really feel like I shouldn't look inside a psu without knowing anything. I am a software guy!

Yep - that sounds like really sound advice at this point. PS for these machines can be had relatively cheap, so remember that before paying someone more than double-triple the cost of a replacement. I say double or triple because often, purchasing something that's been properly refurbished will last longer than something of this vintage that hasn't.

[Super TWiT]

I will go down there soon, and report back my findings. And to think I almost didn't say anything about the light! I don't know how much they charge. I only paid 35 bucks for the 500 and the psu together so... Also, how hard is the at power supply hack?

[save2600]

Good luck and let us know! Also, let them know what the stuff they may be working on is worth so that way, they know not to rape you on service. Mention that you'd like some preventative maintenance done too, like all electrolytic caps replaced. Same with the diodes/bridge rectifiers. Those things are small and they should be able to quickly give you an estimate.

[Super TWiT]

I wish I was competent enough to do this all myself. Sounds like I might be in for a pretty penny....

[save2600]

Also, how hard is the at power supply hack?

Not hard at all if you want to go that route. There's schematics out there and with a little common sense, you can wire it up to the blown power supply connector yourself. Amigakit sells an adapter already wired also, and maybe someone else on ePay.

-WARNING-

AT power supply and its wires dangling all over like an octopus out of water is FUGLY!  lol

[Super TWiT]

Hey, I don't know if this means anything, but when I turn on the power supply with nothing connected, there is no noise.

[ElPolloDiabl]

I can so good things about learning electronics and it is not hard to learn the basics. Learn Ohm's law, resistors, and then DC power supplies. It will give you the confidence to crack something open and replace fuses or clean up internals.

[ElPolloDiabl]

double post

[Super TWiT]

Good news! It turns out that I wasn't really testing it properly because I put the test probes against the pins not on the pins. Because of that I was getting the humming noise. I got good voltages (I will post) but I have one more to check: the negative 12 volt lead. Is it okay to use my meter's positive lead to check the negative 12 volt lead? It should be right? Because even though the positive lead is called positive, it actually excepts any voltage.

[save2600]

Sure, it'll just show the minus sign in front of the value -12 (or close to it) instead of 12 in the window.

[Super TWiT]

Okay, how do these voltages sound:

Pin 1 (+5 volts): 5.16 volts
Pin 3 (+12 volts): 12.19 volts
Pin 5: (-12 volts): -11.97 volts

All of these voltages sound good except Pin 5 seems a bit low.

No humming either! Before I must have shorted the pins against the ground container shield. Hmm.. sounds like a great way to mess up my psu. I know a little more than before as I have been reading up.