Thermaltake TR2-500 Primary cap bad?

[c_hegge]

Re: Thermaltake TR2-500 Primary cap bad?

I found a similar thing with the CWT branded version that now power's my brother's PC. I left the can controller unmodified, and it still doesn't run that hot.

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

The fan mod failed.

The 9.1kohm resistor made the fan run full speed after some minutes of normal PC use. I tried 10Kohm but it was pretty much the same.

Since I don't have bigger resistors laying around and the psu doesn't run very hot I let the fan controller unchanged.

[ben7]

Re: Thermaltake TR2-500 Primary cap bad?

I got the replacement caps I ordered!

2x1000uF 200V Panasonic UQ

With the new primary caps installed I get 162.5V across each capacitor.


I modded the fan controller circuit to make the psu run cooler.

I put a 9.1kohm resistor in parallel with the thermistor, as you can see in the last picture. The psu has not been tested yet with a PC, so I cannot be sure about its impact on the fan controller.

I want to thank everyone for your help and support.

Good job as always!

Cheerz

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

I got the replacement caps I ordered!

2x1000uF 200V Panasonic UQ

With the new primary caps installed I get 162.5V across each capacitor.


I modded the fan controller circuit to make the psu run cooler.

I put a 9.1kohm resistor in parallel with the thermistor, as you can see in the last picture. The psu has not been tested yet with a PC, so I cannot be sure about its impact on the fan controller.

I want to thank everyone for your help and support.

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

That voltage boost circuit is the definition of crap. The caps are going to drain even if they put Rubycon 105°C in there. Too much heat. Why spend money on that circuit (resistors, diodes and capacitors) when it is not going to last more than a couple of months? My theory is that they do this to trick reviews about efficiency.

Removing the caps was the first thing to do to disable that circuit. The caps were Teapo, completely dead as expected.

Not sure why they failed, either. I've seen high resistance resistors like that fail for no reason before, though.

Where were the failed resistors?


Out of curiosity I checked the bleeding resistors of more than 15 power supplies (fortunately I take pictures of every psu I open) and they all had values ranging from 150kohm to 250kohm. A Konig power supply had 1000kohm resistors! The only exception was the Jou Jye psus, that had 65kohm resistors. But those resistors were clearly of higher watts than the others, 1/2watt probably.

I assume that the 100kohm 1/4watt bleeding resistors of that Thermaltake were quite on the low side.

240AC*1.41=339V

339V/2=170V

(170^2)/100000 = 0.289W

0.289W is more than the maximum allowed 0.25W those resistors are rated. The voltage boost circuit might have made things even worse.

I hope the problem is solved with the 180kohm resistors I put.

[momaka]

Re: Thermaltake TR2-500 Primary cap bad?

I doubt if the boost circuit would have caused the bleed resistors to fail, though.

Yeah, I doubt it too. I didn't even notice the bit about the failed bleed/balance resistors, though. Yes, if they fail, they may cause the voltage across the caps to shift from one cap to the other, thus possibly over-volting one of the caps slightly.
Not sure why they failed, either. I've seen high resistance resistors like that fail for no reason before, though.

[c_hegge]

Re: Thermaltake TR2-500 Primary cap bad?

^
I think he removed the boost caps, which disables the boost circuit. I often do this to CWT PSUs. It's not needed and gets too hot. I doubt if the boost circuit would have caused the bleed resistors to fail, though.

[momaka]

Re: Thermaltake TR2-500 Primary cap bad?

I *think* I found your problem...
See the resistors and diodes next to that PFC connector (one of the resistors is labeled R88) in this picture?
...
Well, does that circuit look familiar?
Hint: *Jou-Jye primary boosting circuit*

I think you have the same problem here. I don't see the boosting caps, though. So maybe it isn't the same circuit. Any chance you can draw it out?

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

I placed 180kohm resistors rated for 1/4watt.

The voltage of each cap is 158V. That gives 0.139 watt, so the new resistors hopefully wont burn up.

[ben7]

Re: Thermaltake TR2-500 Primary cap bad?

I have seen 65kohm, 100kohm, 150kohm, 200kohm and 250kohm resistors on psus. I hope they will be ok. I try not to put parts on the underside for safety reasons.

Safety reasons? There usually is plastic under the circuit board to isolate the bottom connections. If it does short to ground, then the fuse should blow. If there is no ground in the wall socket, then it's not your fault.

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

I have seen 65kohm, 100kohm, 150kohm, 200kohm and 250kohm resistors on psus. I hope they will be ok. I try not to put parts on the underside for safety reasons.

[ben7]

Re: Thermaltake TR2-500 Primary cap bad?

If I use 200kohm resistors wouldn't that improve efficiency and help the power supply generate less heat?

Yes it would. But I think the resistors even out the voltage better if they are at a lower value. (more current can flow - but also more heat is dissipated)

Is it possible to put larger 100K resistors on the underside of the board?

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

If I use 200kohm resistors wouldn't that improve efficiency and help the power supply generate less heat?

[tom66]

Re: Thermaltake TR2-500 Primary cap bad?

(160^2)/100000 = 0.256W

That is 1/4W. Using a 1/4W resistor should be fine up to 70°C or so. I'd prefer a 1/2W or 1W for long term reliability though.

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

^
https://www.badcaps.net/forum/showth...eeder+resistor

See post #6. Anywhere between 100 and 200K should be fine, but both should have the same value.

Thank you!

I would just use the same value (100K). BUT, use a higher wattage one too - hopefully it won't burnout anymore!

-Ben

Higher wattage wont fit there.

Btw I removed the resistors and plugged it in again. Every cap now has 161-165V across its legs.

[ben7]

Re: Thermaltake TR2-500 Primary cap bad?

I would just use the same value (100K). BUT, use a higher wattage one too - hopefully it won't burnout anymore!

-Ben

[c_hegge]

Re: Thermaltake TR2-500 Primary cap bad?

^
https://www.badcaps.net/forum/showth...eeder+resistor

See post #6. Anywhere between 100 and 200K should be fine, but both should have the same value.

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

Put two good caps in there for a moment, and power it on. Take note of the voltage across each primary cap. Occasionally, if there is a problem with the PSU, one cap will have a higher voltage across it that the other, sometimes enough (greater than 200v) to cause it to fail.

open bleeder resistor.replace both.
i see this often in the plate supply in large linears.open bleeder means blown cap.BANG!!!

Bingo!

I followed your advice and checked the bleeding resistors.

They should be 100kohm according to the color code and that's what I got from one of them. The other resistor, the one connected in parallel to the capacitor that failed, is open.

I put 220uF 200V primary caps and plugged it on AC. The cap with the open resistor gets 235V across its legs and the other only 85v. The total rectified voltage is 320V.

Thank you very much for the insight! I am going to replace both of them. How many kohm I should put? Should I stick to the original value?

[goodpsusearch]

Re: Thermaltake TR2-500 Primary cap bad?

By the way, I don't know if anyone else noticed the 5vsb critical cap is a Teapo SK 47uF 35V 85°C. Yes, it's true. They chose to put an 85°C capacitor on 2 transistor 5vsb circuit.

One would expect that CWT, responsible for the Antec psus killing motherboards back in the 00s, would take a lesson and implement an IC (for example DM311) based 5vsb circuit or at least choose a cap less prone to failure.

We are talking about the same psu maker that uses Capxon caps on 5vsb output filter on the Corsair CX power supplies.

Shame on you CWT!!!

[kc8adu]

Re: Thermaltake TR2-500 Primary cap bad?

open bleeder resistor.replace both.
i see this often in the plate supply in large linears.open bleeder means blown cap.BANG!!!