Re: Acer 42" LCD tv no power or stdby light
well its time for an update, I received the ic300 chip for $4 including shipping to New Zealand, soldered it in and tried it out, guess what. Its fixed and back to itself, thank you very much Budm for your help and diagnosis.
slowcap
Member
Last Activity: 05-05-2023, 04:26 PM
Joined: 02-24-2013
Location: nz
-
Re: Acer 42" LCD tv no power or stdby light
I have ordered a new ic300 chip, it part number is DLA001D pwm controller, will update when I put it in.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
Is that the ic300 ?Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
hi, I did follow both gates and both go to the IC300, I soldered a wire to the +ive and the -ive side of the large cap and checked the voltage when pluged in, and its 349 at rest then 415vdc when turned onLast edited by slowcap; 04-18-2013, 01:53 AM.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
UPDATE:
receiver the new mosfet's today, decided to not replace the driver ic as was willing to take the risk, soldered in the new fets and the old bridge rectifier, new fuse and plugged it in, to my surprise no pops or explosions, and the standby light is now on, so I pressed the power button on the remote and the light turned green, and that was it, no picture and no sound, I checked and there is no 24v for backlight and no 12v from power board, so all I have is 5v, there is .4v on the 24v line from the board to backlight,...Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
Ok , will replace the ic aswell, which are the gate drive diode and resistor that I should check/replace? ,
here are some much better pics, with same phone but with sunlight....Last edited by slowcap; 04-10-2013, 06:32 PM.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
That is exactly what seems to be happening, is there a way to test the gate drive circuit with the mosfets removed?, as I'm having to import them from uk to newzealand would rarer not blow up some new ones, I am looking to buy an oscilloscope in a couple of weeks, no help right now of course.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
Thanks for the reply have ordered the new mosfets from uk, will look at the other components tomorrow,
The post about replying was not directed at people who generously give up their time to help others, it was more intended for other people who ask questions and get help but never return to give the results, IMHO a lot of new threads could be avoided if a final post said "yes that fixed it" , I'm not talking about this awesome forum but from my hours of searching other forums and google results that don't...Last edited by slowcap; 04-10-2013, 04:18 AM.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
well I cant edit the last post anymore so will have to reply.
the mosfet is a n channel, number on it is 15n60c3, anyone know what it does? if it has shorted will this blow the fuse?
update: just unsoldered both FETS and both are shorted. will replace tomorrow.
Question. is there any point updating this thread? , just thought it might be useful for anyone else with problems of a similar nature. I hate it when people ask questions, get answers, then go away and not follow up with...Last edited by slowcap; 04-09-2013, 03:17 AM.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
here theres might be better.
just found the fuse now blown. replaced fuse and it blew it straight away. maybe the FET Q301?...Last edited by slowcap; 04-09-2013, 01:24 AM.Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
hi, the burn mark around the resistor is from the first cap discharge...Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
I replaced the resistor, it was 0.1ohms, was a carbon resistor but could only get a 5w wire wound resistor, the board had been out all night and when I went to put the resistor in had a few big sparks as cap discharged, about 4 sparks in total. all in and still nothing,
one photo is of the board and I have circled in red where the resistor sits underneath. the second photo is the replacement resistor (red circle) and the FET that it connects to (black circle) there is a cap that jumps the same gap as resistor,
...Leave a comment:
-
Re: Acer 42" LCD tv no power or stdby light
just found a blown resistor in the primary circuit of the power suppy, its resistor R841 can someone please tell me the ohms, board is a delta DPS-291APLeave a comment:
-
Acer 42" LCD tv no power or stdby light
The model is at4220b and power supply board is a delta dps-291ap , it happened after we unplugged it from the mains and then replugged it in, there is no standby light and it won't turn on, the fuse is good in primary power supply and we have 240v coming in, no leaking or bulging caps and nothing looks shorted or dry soldered, no power on pson wire , no 5v 12v or 24v on wires from the power supply board, I had power supply board out and looked it over, when I fitted it back in , I turned it on, heard a crackle from power supply board area and it powered up , with standby led and also turned on,... -
Re: Acer At3201w will power up sometimes
any update to this? I have the same problem, on a side note I hate how people ask questions and then go away and fix whatever it is they are fixing but never return to update everyone on what fixed the problem.Leave a comment:
No activity results to display
Leave a comment: