The best Sun Pro you've ever seen

[Pentium4]

Double forward, with huge heatsinks and good silicon. Currently trying to get the 5VSB to not run so hot. There's that 21Ω resistor on the bottom side and 33Ω on the top. Without the bottom one, the 5VSB runs at 8.45V I'll upload more pics later

[Pentium4]

Re: The best Sun Pro you've ever seen

The primary uses two Fairchild 9N90C FET's on the primary. The label claims 450W, which seems pretty honest. It looks to have two 12V rails with OCP. Controller on the secondary is PS222S https://cdn.badcaps-static.com/pdfs/...ec01b02f46.pdf

There is a Texas Instruments TL3843P on the primary. Uses an 80mm fan for intake and 120mm for exhaust. All caps were Canicon/CS/JEE/GL. Only one CS cap and two GL caps. The 2200uF 6.3V CS cap failed on the 3.3V after the coil. I think for two reasons: It was physically touching the -12V output rectifier, and it was 8mmx20mm. Seems small, must be GP (No series printed on it) The only other caps that failed was the 100uF 10V JEE on the -5V rail, and both 4700uF 10V Canicon on the 5V filtering. I was blown away that both 3300uF 16V JEE on the 12V filtering were okay. They tested 3367uF 0.02Ω and 3412uF 0.02Ω. Those caps I put in are 30mm tall, so look how big that those toroids are! The heatsinks are huge too.

I can't get the 5VSB to run correctly without the original 5VSB resistors, which seems odd to me. However, I had to replace the 5VSB output inductor, because a leg fell off the original one when removing, because it got so hot!

[domas]

Re: The best Sun Pro you've ever seen

Strange. Did you change 5vSB caps?

Idiotic design if it does so.

[stj]

Re: The best Sun Pro you've ever seen

the clearance between the fuse, thermister and the nearby low votage stuff is way to low!!

[momaka]

Re: The best Sun Pro you've ever seen

Double forward, with huge heatsinks and good silicon.

Seems like Sun Pro is definitely picking up a little - or at least in terms of components sizes. That output inductor is definitely ginormous !
However, the quality of the craftsmanship (if you can call it that) still looks poor. They really need to start paying their workers a bit more.

Currently trying to get the 5VSB to not run so hot. There's that 21Ω resistor on the bottom side and 33Ω on the top. Without the bottom one, the 5VSB runs at 8.45V I'll upload more pics later

8.45V!?!? That's a motherboard killer right there, or at least a competitor for the 250W Bestec 12E. Either Sun Pro seriously messed up on the design here -OR- something went wrong during manufacturing.
The 5VSB should be at most 5.25V without those two resistors. Is it a 2-transistor design or something else? Any suspicious caps near the 5VSB circuit?

the clearance between the fuse, thermister and the nearby low votage stuff is way to low!!

I agree. May want to add a plastic sheet to separate them or something.

[Pentium4]

Re: The best Sun Pro you've ever seen

Strange. Did you change 5vSB caps?

Idiotic design if it does so.

I did. I changed the original 1000uF 10V GL with 1000uF 10V nichicon PW, and changed the 330uF 10V JEE with 1000uF 10V nichicon PW.

the clearance between the fuse, thermister and the nearby low votage stuff is way to low!!

True. Although, I did move the thermistor to get a better view of the 5VSB.

Seems like Sun Pro is definitely picking up a little - or at least in terms of components sizes. That output inductor is definitely ginormous !
However, the quality of the craftsmanship (if you can call it that) still looks poor. They really need to start paying their workers a bit more.

Yeah, mainly the soldering side. I'll take a solder shot, but I've already redone a lot of the joints.

8.45V!?!? That's a motherboard killer right there, or at least a competitor for the 250W Bestec 12E. Either Sun Pro seriously messed up on the design here -OR- something went wrong during manufacturing.
The 5VSB should be at most 5.25V without those two resistors. Is it a 2-transistor design or something else? Any suspicious caps near the 5VSB circuit?

Yeah, and it ran at 5.74V when the computer was running. The lowest it's got was with a single 47Ω resistor. I'll try it with none and see what it does. Otherwise, I may have to do a everell style mod. Yes, it is 2 transistor.

[stj]

Re: The best Sun Pro you've ever seen

dying opto-isolator?
does it use a 431 ?

[momaka]

Re: The best Sun Pro you've ever seen

I'll try it with none and see what it does. Otherwise, I may have to do a everell style mod. Yes, it is 2 transistor.

Oh boy! Get the dim incandescent bulb tester ready! I still think it's a little early for 4th of July fireworks

Yeah, stj is on the right track - try a new 431 shunt and new optocoupler. Look for a critical cap too. Or perhaps the small 5VSB transistor on the primary driving the large 5VSB transistor is open or shorted?

[Pentium4]

Re: The best Sun Pro you've ever seen

Replaced the opto and TL431, even though they both tested good. It was doing the same thing. No critical cap in this design.
I tried with no resistor, and the voltage was all over the place, between 6.97 and 7.4V. So I tried something that I knew would probably be a bad idea, but I wanted to see if it would do what I thought it would, and it did. I installed just a 5Ω resistor, and the voltage was a stable 5.06V, but the resistor melted the heatshrink around it in about 20 seconds

[stj]

Re: The best Sun Pro you've ever seen

any non-electrolytic caps in the circuit?
specially film types?

[Pentium4]

Re: The best Sun Pro you've ever seen

Just ceramic

[momaka]

Re: The best Sun Pro you've ever seen

I guess try the optocoupler next. Before that, though (since you have the 5VSB transformer out), pull the small 5VSB transistor that drives the bigger 5VSB transistor on the heatsink. Check its B-C and B-E diode properties. If okay, put it back in and then try a new opto.

[Pentium4]

Re: The best Sun Pro you've ever seen

I had already replaced the optoisolator

pull the small 5VSB transistor that drives the bigger 5VSB transistor on the heatsink

Are you talking about the one to the left of "J22" ? I think it's a 945. I'll check tomorrow. The 431 I replaced is U9