Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

[stefos]

Hello @ll !!!

I am trying to repair Trust 420W PSU, model PW-5210 (http://www.trust.com/en/all-products...ual-fan-pw5210).

When I checked the psu for the first time I founded in primary side:

1. Glass fuse was blown.
2. 2 x Power FET's MJE13009 was shorted.
3. 2 x 0.5 Ohm, registors (R4, R5) was burned.
4. 1 x Orange or Red + ? + ? + Gold, registor (R7).
5. 1 x 472 1KV capacitor missing one leg.
6. 2 x 10uf 50V was burned.

1, 2, 5 and 6 replaced with new one.
Because I couldn't found 0.5 Ohm (Green-Black-Silver-Gold) registor, I have used 2 x 1.2 Ohm.

R7 registor measured as 10K with my MM but I am not sure if it's the correct value. I used 2.6K registor instead.

When I switched on the psu with the light bulp in serial, I got in my psu tester +5vsb output only and no shorts.

Ic's are AZ7500BP-E1 and AZ339P-E1.

Can you please give me information to make it work? What else to check?

Thanks in advance.

[Escort Eagle]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

May be your Controller Section has gone . Specially the IC AZ7500BP . Check the voltage on IC PIN 4, 8 & 11 in both state (AZ7500BP). Check the two switching transistors (C945/C1815)- are they ok or not . And check T2 transformer's PIN voltage in both state . I think most probably your IC AZ7500BP has been damaged . This is why your MJE13009 has blown .

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

May be your Controller Section has gone . Specially the IC AZ7500BP . Check the voltage on IC PIN 4, 8 & 11 in both state (AZ7500BP). And check T2 transformer's PIN voltage in both state . I think most probably your IC AZ7500BP has been damaged . This is why your MJE13009 has blown .

I've changed both ic's with new one using TL494CN and LM339N but seems there was ok because voltages measurments was same as old IC's.

IC: TL494CN (PS_ON state ----- PS_OFF)
===============================
1: 0.5 m v
2: 4.427 v
3: 61.8 mv
4: 34.6 mv --- 3.364v
5: 1.496 v
6: 3.733 v
7: 0.5 mv
8: 1.602 v --- 2.365 v

9: 0.7 mv
10: 0.6 mv
11: 1.6 v --- 2.363 v
12: 10.35 v --- 10.37 v
13: 5.018 v
14: 5.018 v
15: 5.016 v
16: 472 mv


IC: LM339N (PS_ON state)
===================
1: 4.252 v
2: 35.1 mv
3: 5.018 v
4: 1.248 v
5: 0.792 v
6: 0.6 mv
7: 2.457 v

8: 1.334 v
9: 62.7 mv
10: 1.1 mv
11: 1.2 v
12: 0 v
13: 0 v
14: 4.2 mv

OPTO: (PS_ON state -----PS_OFF)
======================
pin 1: 5.079 v --- 5.075 v
pin 2: 4.010 v --- 4.008 v

T2 transformer (PS_ON state -----PS_OFF)
============================
pin 1: 1.560 v --- 1.617 v
pin 2: 1.560 v --- 1.617 v
pin 3: 1.560 v --- 1.617 v

Green color at PS_ON state does not have voltage, but on switching off state has 5.015 v.

When I shorted pin 4(DTC) with pin 7 (GRD) on TL431CN ic, psu didn't worked, only +5vsb output was ok.

Check the two switching transistors (C945/C1815)- are they ok or not .

Checked most of the transistor's and those in attached image. Can I make some voltage measurement to verify that are working as expected?

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

Found 2 x 1N4148 bad and replaced, but still no go. Only +5vsb

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

When I shorted pin 4(DTC) with pin 7 (GRD) on TL431CN ic, psu didn't worked, only +5vsb output was ok.

ops type mistake..

When I shorted pin 4(DTC) with pin 7 (GRD) on TL494CN ic, psu didn't worked, only +5vsb output was ok.

[Escort Eagle]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

1N4148 are damaged but Surprisingly C2235 are survived !!

When you are shorting 4+7 Pins, then what is the voltage in T2 Transformer Pin ??

Replace those Components with new one . Shown in the image . Let's see what happens .

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

When you are shorting 4+7 Pins, then what is the voltage in T2 Transformer Pin ??

I shorted pins 4+7 and power on psu with light bulp in series using psu tester.
Got +5vsb only.

1. Fan no rotation as always.
2. Voltage on T2 1-2-3 pins was 1.825v and produced 0.001v voltage drop every 10 sec. About 10-15 min later voltages was 1.750v.

Replace those Components with new one . Shown in the image . Let's see what happens .

Desoldered 100 Ω, 620 Ω registors and 1N4148 diode tested and founded OK.

[Escort Eagle]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

I told you to replace those components .

At the time of 4+7 what is the voltage at 8 and 11 PIN ??

Check the T2 Transformer - Is it ok or not ? 1,2 & 5 will give you continuity and 3 & 4 will give you continuity . Shown in Image "IM-01"

As far as I can Remember - I repaired a Power supply which Transformer was same like as yours . I can remember that power supply was not running . Every Parts was OK but PSU was not turning on !! Then I changed the T2 transformer but Power supply did not run !! At last I changed the Main T1 Transformer and PSU Started running . But Meter is showing Transformer is OK !! My Meter is giving continuity in both Primary side and Secondary Side . No side is open . That transformer still is in my vault . I have uploaded the Picture of that Transformer "IM-02" .

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

I told you to replace those components .

At the time of 4+7 what is the voltage at 8 and 11 PIN ??

Check the T2 Transformer - Is it ok or not ? 1,2 & 5 will give you continuity and 3 & 4 will give you continuity . Shown in Image "IM-01"

As far as I can Remember - I repaired a Power supply which Transformer was same like as yours . I can remember that power supply was not running . Every Parts was OK but PSU was not turning on !! Then I changed the T2 transformer but Power supply did not run !! At last I changed the Main T1 Transformer and PSU Started running . But Meter is showing Transformer is OK !! My Meter is giving continuity in both Primary side and Secondary Side . No side is open . That transformer still is in my vault . I have uploaded the Picture of that Transformer "IM-02" .

I had replaced the 2 resistors (100 Ohm and 620 Ohm) and 1N4148 diode, but the psu didn't work, so this is the reason I mentioned that those parts were tested and founded to be okay.

At the time of 4+7 what is the voltage at 8 and 11 PIN ??

Voltage measurements on TL494 IC was as following:

Pin 1: 1.3 mv
Pin 2: 4.930 v
Pin 3: 62 mv
Pin 4: 0.6 mv
Pin 5: 1.497 v
Pin 6: 3.706 v
Pin 7: GRD (0 v)
Pin 8: 1.591 v
Pin 9: 0.6 mv
Pin 10: 0.6 mv
Pin 11: 1.581 v
Pin 12: 10.37 v
Pin 13: 5.012 v
Pin 14: 5.012 v
Pin 15: 4.018 v
Pin 16: 517.8 mv

T2 Voltage on pins 1-2-3 was 1.751 v and continuity test was exactly as you refered.

Unfortunatlly I don't have this type of T1 transformer to try it out.My meter gives continuity in both 1-2-3 primary pins and 1-2-3-4-5-6 pins on secondary side.

[Escort Eagle]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

Your TL494 is switching properly . The Problem is laid after the IC to T2 Transformer . First Replace the Switching Transistors C2235 With C945/C1815 . Let's see PSU runs or not .

Still the PSU is not running then change the T2 Transformer . I think it will solve your problem . To change the T2 Transformer you must be careful that Vdd will be in side position and other two pins will connected with switching transistors . Shown in Image "IM-03" . And Primary side's Pin Continuity will also match with the Original one .

By the way - In primary side All Parts are OK ?? I mean Four 1N4148 Diodes and two capacitors which you replaced - are they in right direction ??

[stefos]

Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output

Your TL494 is switching properly . The Problem is laid after the IC to T2 Transformer . First Replace the Switching Transistors C2235 With C945/C1815 . Let's see PSU runs or not .

Replaced with 2 x C945 didn't fix the problem.

Still the PSU is not running then change the T2 Transformer . I think it will solve your problem . To change the T2 Transformer you must be careful that Vdd will be in side position and other two pins will connected with switching transistors . Shown in Image "IM-03" . And Primary side's Pin Continuity will also match with the Original one .

Used another T2 transformer with same continuity and got same voltage output (see image [470]). Problem remain.

By the way - In primary side All Parts are OK ?? I mean Four 1N4148 Diodes and two capacitors which you replaced - are they in right direction ??

Test out of circuit 4 x 1N4148 diodes and was ok and the new caps direction is ok too (negative polarity is facing pFET's).

Probably the problem exists on T1 transformer as you mentioned before.