Deer DR-A300ATX so close to decent!

[momaka]

Re: Deer DR-A300ATX so close to decent!

Bump: I have one of the gutless Deer/Allied/L&C which I had recapped earlier, and all was fine for years (8+ years), but the +5Vsb has finally died (i.e. no +5Vsb on power up).
...
What's the next thing to check

Since this is a 2-transistor self-osicllating circuit, my guess would be it went overvoltage or something equally catasrophic happened. You said the MOSFET was shorted, so check that the two primary windings on the 5VSB transformer haven't gone open circuit. Also check the Source power resistor for open circuit and the drive transistor (usually a C945 TO-92 device) for open and short circuit between pins. Change the 5VSB critical cap on the primary side (50V 22 uF, if I remember correctly). I highly suggest you check and/or change the optocoupler as well if you have a spare one.
Finally, check the snubber network on the primary winding of the 5VSB transformer.
... in short, check everything on the 5VSB . 2-transistors circuits tend to destroy parts when something goes bad, so check your new parts too, now. Also, I suggest using the series light bulb trick to prevent further damage to the 5VSB when testing it.

[linuxguru]

Re: Deer DR-A300ATX so close to decent!

Bump: I have one of the gutless Deer/Allied/L&C which I had recapped earlier, and all was fine for years (8+ years), but the +5Vsb has finally died (i.e. no +5Vsb on power up). All secondary caps from previous recap seem fine. Checked and replaced the main fuse and the (shorted) 2N60B MOSFET switch for the auxiliary flyback. However, +5Vsb doesn't come on, i.e. auxiliary flyback doesn't start up.

What's the next thing to check, and is the 2N60B the original MOSFET on these units? Is there any suggested upgrade or uprated MOSFET that works reliably for the auxiliary?

[everell]

Re: Deer DR-A300ATX so close to decent!

Here is information on that 2003 chip

https://www.badcaps.net/forum/attach...0&d=1391561507

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

Out of curiosity, what values does your PSU has for R1 and R2 (the 2 balancing resistors across the primary caps)?

Interesting. I recall mine were both 330k, but TELVM's were of different values. I guess that's another unexplicable Deer/L&C "thing" just like the 3.3V torroid coil swapping.

That was no mistake after all!!! They do it intentionally!!

I got an Allied 2006 psu with the same asymmetry in bleeding resistors!

R3: 462kohm and R4: 330kohm

I have no idea why they did this, but it might have impact on the caps. The caps are Koshin 200V 470uF and their capacity is:
481uF (in parallel with 462kohm R3)
465uF (in parallel with 330kohm R4)

Any input would be welcome at that point..

TELVM's thread: https://www.badcaps.net/forum/showth...586#post284586

[Th3_uN1Qu3]

Re: Deer DR-A300ATX so close to decent!

Fan controller?
Oh my! Your Deer really is fancy . I don't ever recall seeing a Deer with one.

I had one with huge heatsinks, EI-40 transformer, full input filters and full pi filters. Too bad it was full of Rulycons which is what killed it. It had so many bad caps of all shapes and sizes that it was not worth saving.

[momaka]

Re: Deer DR-A300ATX so close to decent!

Challenge accepted:
https://www.badcaps.net/forum/showpo...&postcount=524

Alright,

Notice how they replaced the torroid coil for 3.3V with an output filter choke!! This is incredible!

Yeah, that ANS LC-235ATX I posted in the same link above has that too. The funny bit is that none of the caps inside it have gone bad yet (at least not visually) and that PSU was in good use for close to 5 years.

The 2 balancing resistors are of the same value. I checked the color code on them, they are identical, but I can't recollect what values they were..

Interesting. I recall mine were both 330k, but TELVM's were of different values. I guess that's another unexplicable Deer/L&C "thing" just like the 3.3V torroid coil swapping.

The fan is Xinruilian. I think it still works because of the fan controller not stressing it too much.

Fan controller?
Oh my! Your Deer really is fancy . I don't ever recall seeing a Deer with one.

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

Now compare to this (the LC-B300ATX, that is. Same PSU.... well, design-wise):
https://www.badcaps.net/forum/showth...302#post224302

Out of curiosity, what values does your PSU has for R1 and R2 (the 2 balancing resistors across the primary caps)?

Also, what brand was the fan?

Challenge accepted:
https://www.badcaps.net/forum/showpo...&postcount=524
Notice how they replaced the torroid coil for 3.3V with an output filter choke!! This is incredible!

The 2 balancing resistors are of the same value. I checked the color code on them, they are identical, but I can't recollect what values they were..

The fan is Xinruilian. I think it still works because of the fan controller not stressing it too much.

You could cut the legs shorter and then solder thick piece of wire to them and then solder that to the board.
That's just an idea though. I have 1 rectifier like that that I want to use in a PSU but never got around to trying to see if that idea actually works.

Yeah, I could do that, but it's not worth the time. I already used that MBR20100 in another psu that had F12C20 with success. It had to do with the height of the screw holes on the heatsink.

[momaka]

Re: Deer DR-A300ATX so close to decent!

The best Deer/L&C I have got so far. It has even MOV protection!

Now compare to this (the LC-B300ATX, that is. Same PSU.... well, design-wise):
https://www.badcaps.net/forum/showth...302#post224302

Out of curiosity, what values does your PSU has for R1 and R2 (the 2 balancing resistors across the primary caps)?

Also, what brand was the fan?

The MBR20100 had very short legs for that psu and it was impossible to make good contact with the PCB no matter how much solder I used...

You could cut the legs shorter and then solder thick piece of wire to them and then solder that to the board.
That's just an idea though. I have 1 rectifier like that that I want to use in a PSU but never got around to trying to see if that idea actually works.

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

I don't have the equipment to measure that unfortunately.

[Pentium4]

Re: Deer DR-A300ATX so close to decent!

Nice! What's the efficiency like on yours? Mine at 110W was 72% and 180W was 73%

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

The -12V had a DON 470uF 16V capacitor that had started to fail. I replaced it with 470uF 16V Teapo SX.

[Pentium4]

Re: Deer DR-A300ATX so close to decent!

Very good power supply! What brand and series are the 4 caps that failed?

I know I wish Deer still made PSU's like these 2! DON caps, they failed terribly didn't they? The rest is that single Jun Fu, and the smaller ones are a mix between G-Luxon and Elite

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

This looks very similar to my old Allied power supply manufactured in Feb. 2002. Deer built better PSU's back in the day...

Very good power supply! What brand and series are the 4 caps that failed?

[Pentium4]

Re: Deer DR-A300ATX so close to decent!

This looks very similar to my old Allied power supply manufactured in Feb. 2002. Deer built better PSU's back in the day...

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

You sure the diode you put in isn't shorted? Also recheck your soldering on the 12v output cap.

My bad

The MBR20100 had very short legs for that psu and it was impossible to make good contact with the PCB no matter how much solder I used...

I ordered some MUR1620CT but I have to return the computer sooner than I receive the rectifiers, so I used an F12C20. The TO-220AB package will help in better heat dissipation than the fully insulated package of the rectifier it originally had.

did it still fire up before you started?
one step at a time and check your work at each stage.
but yes if that has been going since 2003 its had a good life.
see a ton of those branded allied here.recap and good as new.oil the fan too.

I oiled the fan, thanks for reminding me! I was surprised to see that it had some lubricant inside already. I don't know if it was in good condition though. It was not transparent.

[kc8adu]

Re: Deer DR-A300ATX so close to decent!

did it still fire up before you started?
one step at a time and check your work at each stage.
but yes if that has been going since 2003 its had a good life.
see a ton of those branded allied here.recap and good as new.oil the fan too.

[Th3_uN1Qu3]

Re: Deer DR-A300ATX so close to decent!

5vsb is ok but when shorting green to ground it doesn't power on. All the rails try to turn on for a second except the 12V.

You sure the diode you put in isn't shorted? Also recheck your soldering on the 12v output cap.

[goodpsusearch]

Re: Deer DR-A300ATX so close to decent!

1000:th post, congratz goodpsusearch!
With a name like that you know you just need to fix this PSU up, it deserves it

Thank you very much

Uprating the 12V rectifier and possibly the switch transistors (got any stray 13007s or 13009s?), and replacing the bad caps might give your customer another 2 or 3 years' service from that computer.

Well, about that, I replaced the UF1002F with an MBR20100, and the 12V cap (2200uF 16V) with a 3300uF 16V.

I also replaced the critical 5vsb capacitor (22uF 50V) because it showed 12uF and high esr.

5vsb is ok but when shorting green to ground it doesn't power on. All the rails try to turn on for a second except the 12V.

Could the MBR20100 be incompatible? I have used it at half bridge psus on 12V without any problem till now...

Why that cut in the secondary heatsink just above the +3.3V rectifier? To improve airflow? To save aluminum?

It is there for the PPFC to fit.

Is that PFC choke legit?!

I think it is real.

[ben7]

Re: Deer DR-A300ATX so close to decent!

Is that PFC choke legit?!

[TELVM]

Re: Deer DR-A300ATX so close to decent!

Why that cut in the secondary heatsink just above the +3.3V rectifier? To improve airflow? To save aluminum?