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Testing a Quadra 660AV Power supply..
Posted by: tthoms on 2019-04-02 16:55:46 So, as I try to restore the Quadra, I thought that I'd start with the power supply. Searching the forums, I didn't find anything related to the pin configuration for the 9 pin socket that goes to the motherboard. I took a volt meter to it and this is what I found: Positive lead (Black) to Negative lead (Blue): Voltage seems to oscillate between 3-4 volts. Positive lead (Yellow) to Negative lead (Black): Voltage seems to oscillate between 7-8 volts. Positive lead (Red) to Negative lead (Black): Voltage reads in at 4.2 volts Any idea what that means? Assuming that Black is ground, it seems noisy at least. I looked for a way to open the PSU, but I can't seem to find anything that isn't taking a screwdriver and prying the sheet metal apart. If there is a useful trick, I'd love to hear it. Thanks for any advice you can offer.
Posted by: tthoms on 2019-04-03 16:00:10 So, I figured out how to get into the power supply. At first glance, everything looks good. No bulging capacitors, the board looks really clean, until.... There seems to be a lot of grease or goo around the transformer. Is that normal? if not, can you replace them?
Posted by: Unknown_K on 2019-04-03 16:47:08 My 660av came dead and I ended up replacing my PS and it worked. I meant to see if I can fix it but have not got around to it (fixing PS is not my favorite thing to do). Anyway I might dig it out this weekend and take a look. Are there more then one model of supply for the 660av?
Posted by: Unknown_K on 2019-04-03 19:28:26 Well I was down in the lab working on a DELL and the PS was close by so I took a look at it. Astec AA16990 Apple 614-0022 Capacitor ,Voltage, marked uf, test uf, Ohm, Voltage drop % c25 , 10, 470, 544, .19. 1.3 c27 , 25, 220, 212.5, .19, 1.2 c11, 25, 47, 49.39, 1.2, .9 c28, 16, 1000, 917.4, .18, 1.3 c29, 16, 1200, 1095, .09, 1.3 c26, 10, 2200, 2216, .06, 1.8 c9, 200, 330, 312.6 , .11, .7 c10, 200, 330, 305.5, .14, .4 c45, 10, 220, 236, .28, 2.0 c46, 25, 47, 48.7, .95, .9 c30, 35, 10, 10.96, 4.9, 4.1 C30 seems a bit funky at first look at the numbers.
Posted by: tthoms on 2019-04-03 20:26:33 My 660av came dead and I ended up replacing my PS and it worked. I meant to see if I can fix it but have not got around to it (fixing PS is not my favorite thing to do). Anyway I might dig it out this weekend and take a look. Are there more then one model of supply for the 660av? Not to my knowledge, but I'm new at this.
Posted by: tthoms on 2019-04-03 20:31:38 Well I was down in the lab working on a DELL and the PS was close by so I took a look at it. Astec AA16990 Apple 614-0022 We seem to have the same model. Capacitor ,Voltage, marked uf, test uf, Ohm, Voltage drop % c25 , 10, 470, 544, .19. 1.3 c27 , 25, 220, 212.5, .19, 1.2 c11, 25, 47, 49.39, 1.2, .9 c28, 16, 1000, 917.4, .18, 1.3 c29, 16, 1200, 1095, .09, 1.3 c26, 10, 2200, 2216, .06, 1.8 c9, 200, 330, 312.6 , .11, .7 c10, 200, 330, 305.5, .14, .4 c45, 10, 220, 236, .28, 2.0 c46, 25, 47, 48.7, .95, .9 c30, 35, 10, 10.96, 4.9, 4.1 C30 seems a bit funky at first look at the numbers. I haven't even looked at the capacitors. Does your transformer have orange grease/ goo on it? I'm also curious about the voltages that you get out of the motherboard connector.
Posted by: Unknown_K on 2019-04-03 21:05:05 Looks like glue or epoxy to me.
Posted by: tthoms on 2019-04-05 20:52:56 I found a link discussing this PSU in depth: https://www.badcaps.net/forum/showthread.php?t=62455&highlight=astec+aa16990 It seems you can't measure the voltage output unless the PSU is under load. I'll see what I can figure out.
Posted by: tthoms on 2019-04-06 15:46:28 Using a 12 auto lamp (the kind for static timing adjustments) the new readings are: Yellow 11.8 V Blue 10.9 V Red 4.3- 4.4 still some oscillation on this circuit.
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