Re: Scavenge LED strips from laptop (Backlight Repair)
That's right (Similar to figure 1 of your attached pdf file)....
stefos
Senior Member
Last Activity: 03-27-2023, 09:27 AM
Joined: 05-25-2012
Location: Alexandroupolis
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Re: Scavenge LED strips from laptop (Backlight Repair)
Can you please add a schematic how to power on the leds using the default pcb driver? I have a strip with 9 leds in series x 4 paraller = 36 total leds). Thanks !!...Last edited by stefos; 02-08-2017, 05:05 PM.Leave a comment:
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Hello. I have desoldered one by one tantalum capacitors and have found the shorted one. Thank you alot for your recomendations. -
- Do you have a bench PSU? it will able help you to finding the shorted.
- But if you didn't, then you can desolder one by one.
- Don't apply power till shorted has gone.
- First measure resitance on all big coils
- Then measure on all High side mosfet/ upper mosfet, D-S and otherwise
- report what result. -
Hello Friend and Happy New Year !!!
I would like to ask you if you can help me repair my laptop motherboard (TOSHIBA SATELLITE C50D AMD A4-5000, H000053400 PT10AN). Unfortunatly I can't find the schematic, but I have the bordview. I had left it for battery charging and when I came back and try to use it, the laptop was dead. No power at all. Tried some measurements with my digital MM and only 19v is ok. Using red probe of DMM to GRD and testing parts with black probe, found many caps shorted. In boardview all this parts related to +AC_BAT_SYS. So I believe that +AC_BAT_SYS is shorted... -
Re: PREMIER model DR-8460BTX 450W PSU recap
Dear friend thank you a lot for your advise !!!
I opened again the case and saw that replaced cap value is 22uF and other two capacitors near the small transformer value is 2.2uF....Leave a comment:
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Re: PREMIER model DR-8460BTX 450W PSU recap
The replacement x-fan works smoothly and quite silently in comparison with the original fan....Leave a comment:
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Re: PREMIER model DR-8460BTX 450W PSU recap
This psu uses 2.2uf 50v caps for the +5vsb. Is it better to use this value or 22uf and/or 47uf?
If leave the 12v without anything won't this affect psu stability?
Thanks for you help....Leave a comment:
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Re: PREMIER model DR-8460BTX 450W PSU recap
a) 12v--> (b) 12.49v (a) 12.51v
b) 5v--> (b) 5.181v (a) 5.183v
c) 3.3v--> (b) 3.363v (a) 3.365v...Leave a comment:
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Re: PREMIER model DR-8460BTX 450W PSU recap
The original fan was full of dust and was rotating hardly. I clean it but produced a buzzing sound while spinning.
Thank you all for you suggestions !!!...Leave a comment:
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Re: PREMIER model DR-8460BTX 450W PSU recap
I have replaced all of the electrolytic caps except the two big filter caps because I didn't want to spend too much value for this cheapy psu.
Filter caps measured at 321uf and 337uf with 0.58 Ohms ESR. The small one was rated 50v 2.2μf
Also I resolder the large load resistors on the output as suggested from friend momaka. The default registor values was for 12v -->117.8 Ohm, for 5v -->28.5 Ohm and for 3.3v -->15.8 Ohm.
At 12v I used 330 Ohm registor from another Premier psu and test...Last edited by stefos; 05-23-2014, 02:54 PM.Leave a comment:
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PREMIER model DR-8460BTX 450W PSU recap
Hello !!!
I got this psu from a friend and even there are many bulged caps, psu is still working but with stability issues as expected.
Even is a cheap one model, it's an opportunity to a newbie like me to proceed on recapping as this is the easy part of the work but....
I have read many threads so far about psu improvements and I wondering how this model can be improved. What parts do I have to replace and get e.g. better stability or watt output ?
Thanks a lot.... -
Re: Antec SL450P Smart Power Exploded!
Can you please share a photo of this action?
Thanks a lot....Leave a comment:
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
Replaced with 2 x C945 didn't fix the problem.
Used another T2 transformer with same continuity and got same voltage output (see image [470]). Problem remain.
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.
...
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
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.
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...Leave a comment:
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
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.
Desoldered 100 Ω, 620 Ω registors and 1N4148 diode tested and founded OK....Leave a comment:
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
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....Leave a comment:
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
Found 2 x 1N4148 bad and replaced, but still no go. Only +5vsb...
Last edited by stefos; 04-29-2014, 01:38 PM.Leave a comment:
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Re: Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
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)
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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...Last edited by stefos; 04-29-2014, 09:06 AM.Leave a comment:
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Trust 420W PSU DUAL FAN PW-5210 only +5VSB output
Hello @ll !!!
I am trying to repair Trust 420W PSU, model PW-5210 ([url]http://www.trust.com/en/all-products/14887-420w-psu-dual-fan-pw5210[/url]).
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...
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