johnc12

yes i wont... Ill place it on my archive for safety.... Soon when Ill be working on APC Ill be able to fix that problem... rar

yes i tried it with my old motherboard and also with new ones... and the same problem occurs... I still haven't tried to replace the mosfet... I think tomorrow and I will post here what happend.... :)

I'm not a qualified electrician but supplying higher power to a camera like yours damages internal parts like IC especially sensitive chips that only needed a little supply in them... try what ante said... he's an expert on this. ;D but I think theres a little possibility that you could repair it by you're self.... :)

Aw... hehe... thanks for correcting me. I'll try to review my audio electronics basic :( I think the project is quite expensive and I think troublesome in my part. I've been studying Communication Electronics but when I shifted computer my focus turned into it. But I think I'll give it a try and try to post with my finish pic... :) I asked about this project because I want my extra sony speaker to be connected into my computer..... to really enjoy the sounds without buying new stereo speakers... thanks a lot ;)

I have seen that you've used 555 timer and this circuit is a basic up and down counter I believe. In my school we used atmel 2051 to design down and up counters, timers and etc. or combination. We also used a decoder 74ls47 in our design, but our project is kinda expensive because a we bought the micro controller for $ 8. Try to find designs in the internet. :) goodluck

hehe. Ante, I tried to check the UPS using you're diagram but it shows only little similarity on the pcb. The mosfets, resistors and caps are hard to find and not the same as irf740. My supervisor and I decided to indicate the problem and declares the unit defective and will be replaced... thanks ante... ;)

mr rich did you mean all ceramic and electrolytic caps near the flyback???? ante, do you want me to replace CVBS and check video in circuit in the monitor right? i'm still working in the flyback area and havent replace anythin yet. But I will post any progress. I'm off every sat and sun.... I cant work it this days.... ;D

ante, what do you mean by input connector? All I have here is a video in and AC power in. ???

Yah thanks for that. I was planning to use my broken tip 60 watts solder on it. And i'm kinda hesitant to do so. I also found some site that shows a particular problem like mine, but the monitor model is different. The problem is pointing to the same parts as what you've said. It says that I have to check IRF630A (problem shorted), capacitor 150uf 400v caps and R720 (9.3k) but my R720 is 100k near the flyback and see if it is burned but it is not. ;D I don't know if it still has something to do with my video cable not connected or connected to the cpu. ??? I'm still confuse of it.. But thanks for the help ante... :)

i see now. by reading some materials and some of you're ideas it is now clearer to me. what you've given is a active crossover which uses op amps to drive the speakers and I also seen a project in this site a two way crossover but it is a passive one or the a simple one because it only uses caps, resistors and inductors.. correct me if i'm wrong... :) does the project here (two way crossover) can be use in stereo amp?

hmm. can play both mid and hi? so when i make a 3 way crossover my other satellite speaker can be connected to the mid.... :-\

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graduate of two vocational course in the same year.... Electronics Engineering Technology Major on Communication/Consumer and Computer Electronics MSU-IIT, Philippines..... LOLz.. hehe ;D

hi audio guru, do I have to connect my two satellite speakers to the tweeter output??? what will happen if i do that? johnc

I see, the irf740 is in parallel with 3 irf740 also. I can see that it is found near the ceramic caps and the source. There are also some burned resistors and transistors near the mosfet but it is too small to determine, and I think they are defective too. I would be glad to see you're APC 500 schematic and see if it matches on my unit here. Thanks ante. johnc

hmm... ante i found the mosfet near the flyback and but i'm kinda confuse on how to test the irf630a while it is on the pcb. I'm also afraid to desolder it using my handheld pump and 40w iron. Hope you could help a newbie... :)

Helow guys, Well as a new guy here in office I don't have any knowledge in troubleshooting.... After the busted monitor, now my problem here is the APC ES 500 model BE500-PH. I can't find any schematic that could help me and APC refuse to give me one... My problem is this, my UPS wont start and I found out that one of the MOSFET (IRF740) is burned. I replaced it with a new one but the unit still wont power on. Hope you guys could help me troubleshoot. I have 3 more UPS, the same unit and similar problem, unit wont turn on. I will really appreciate any help that will come. If you have question, don't hesitate to ask. :)

by the way. i didn't touch any component in the PSW. The one I replaced in on the flyback the capacitor 47uf 200V on pin 3. When i turned it on not connecting the video cord on my cpu the monitor power led and other 8 leds are all in standby mode. But when I connect the video cord on my motherboard the problem that I stated on my first post occur.... I hope this doesn't sound confusing guys. hehe.. ante? hehe :D

i'll try checking the supply and feed it... haha thanks ante ;)

Helow guys, i have here in our office an AOC 14" color monitor model 4vn. the screen suddenly turns white and blurred when use for at least 45mins. one of my friend told me to replace the cap near the flyback. so i replaced the 47uf 200V cap to which i think is the problem. after that i tried to connect it back to my cpu but a new problem occur. the monitor turns on but the power led suddenly turns orange (means off). the other 8 leds is just blinking. what could have cause the problem.... ???? i hope someone can help me. i also try to find some service manual and schematics on google but the picture is so unreadable. any help is appreciated... if you have some question please do ask. thanks... :)

hi, hope someone can give me a schematic diagram or datasheet of my AOC color monitor model 4vn. The google gives me a lot of resources but it is so small and details is so unreadable. Thanks in Advance.. ;)

hmm. i tried charging it using my atx power supply and when i measure the voltage it reads 12 Volts... Is it good???

try checking schematics for your monitor by searching using its model number... :)

helow i have here a 47uf 260 V capacitor. My problem is how to test this... what reading shall i get when using analog voltmeter set to Rx10. thanks in advance... :)

thanks audioguru and MP.... i'll try to see if my speaker has a built in filter in it.... but i think it has... just to make sure.... :)