ACER AL1713m no power

[tahir anjum]

Re: ACER AL1713m no power

is there any equivalent for SG6841SZ..coz i can not find it in pakistan. thanks

[Welchs101]

Re: ACER AL1713m no power

thanks!

[PlainBill]

Re: ACER AL1713m no power

In post #27 i posted a question about a 10ohm resistor........can someone take a look at it and let me know what they think?

thanks. hope you all had a nice thanksgiving.

R1 is supposed to be a 10 ohm, .25 watt resistor. In this application it shouldn't make any difference if it reads slightly high, but just to stop you from bugging us, use the 1/2 watt resistor.

PlainBill

[Welchs101]

Re: ACER AL1713m no power

In post #27 i posted a question about a 10ohm resistor........can someone take a look at it and let me know what they think?

thanks. hope you all had a nice thanksgiving.

[newbie1]

Re: ACER AL1713m no power

Well, we share the same symptom & same IC problem (initially) but mine is of different monitor. To cut the long story short, now my HP f1905 is 'dead' likely to be caused by logic card (suspected EEPROM corrupted). Its ok. I keep moving on.. Anyway, I learnt & experienced a great deal from the FANTASTIC guys here, even though the monitor was not revived..

[Welchs101]

Re: ACER AL1713m no power

Newbie, what are the symptoms of your monitor?

I also had to replace the following capacitors:
C867:1000UF/16v => replaced with 1000uF/25V
C862: 1000uf/25v => replaced with 1000uF/25V
C865: 470Uf/25v => replaced with 470uF/25V
C22 and C6: 220uF/25V => replaced with 220uF/35V

also the resistor R852 may need to be replaced.

[newbie1]

Re: ACER AL1713m no power

congrats on the job well done..
mine is still dead after replacing the IC..

As for the resistor, frankly i am not too sure.. maybe the experts here can advise you..

[Welchs101]

Re: ACER AL1713m no power

Part SG6841SZ finally came in. I ordered it off ebay from someone in HongKong ......took a while but i am in no rush.

I removed the old part and put in the new SG6841SZ and BAM! Monitor came back to life.

So you were right.......the SG6841SZ was the bad part.

Question: Regarding the 10ohm resistor.
I think i should replace this resistor......dont you guys?
I have two resistors currently in my possesion that i bought years ago a radio shack for some reason or the other.
Type1: 10-ohm Metal Oxide resistor 1 watt 5% tolerance
Type2: 10-ohm resistor 1/2 watt 5% tolerance

Which one of these should i use....or should i not even use one of these?

Thanks again......

[Welchs101]

Re: ACER AL1713m no power

thanks! I am going to try and place the order today or tomorrow.

[newbie1]

Re: ACER AL1713m no power

thanks newbie1.

so the SG6841SZ is a valid replacement. thanks.

One question, i tried to download the pdf you mentioned in your post.....i had issues downloading it. do you have the actual pdf file?

thanks again.

here you go.

[Welchs101]

Re: ACER AL1713m no power

thanks newbie1.

so the SG6841SZ is a valid replacement. thanks.

One question, i tried to download the pdf you mentioned in your post.....i had issues downloading it. do you have the actual pdf file?

thanks again.

[newbie1]

Re: ACER AL1713m no power

if you look on page 2 of the SG6841 datasheet they are compatible.. SG6841SZ is the lead-free version of SG6841.. I have just used it to replace my faulty SG6841S..

[Welchs101]

Re: ACER AL1713m no power

Ok. I am now finally getting around to ordering the U850 device which is marked on the package as "SG6841S".

I think this is manufactured by fairchild but not 100% sure. I went to this web site and fairchild no longer manufactures this product. But i am not sure what to replace it with.

If you look on ebay you can find the "SG6841SZ" device but not "SG6841S".......what i am wondering is if the "SG6841SZ" device is an equivalent replacement. I thought i could get this info from the fairchild site but i am a little confused from its site because of the "not recommended for new designs" comment on the fairchild site.

Could someone help me ?

[Rtech]

Re: ACER AL1713m no power

Fun with Dick and Jane !!!!!Adult movie.............lol

[PlainBill]

Re: ACER AL1713m no power

Thanks again for the detailed explanation. I always bookmark them and re-read them over and over. I don't want to hijack this thread and get it off topic, but ...

In my area of "expertise", networking, I'm used to reading RFCs, IEEE documents and using protocol analyzers to get the correct "startup/handshaking" sequence. I know exactly what the first packet or frame looks like and what should happen next. I can solve networking problems with over 1,000 routers and switches with the help of the above mentioned.

The thing I find hard in this electronics area is the reading the schematic and understanding the various branches and their sequences. It all looks like "chicken and egg" conundrum. Any books or resources in this area to help would be appreciated.

Reading a schematic for an IPS (inverter / power supply) is no different than reading a newspaper. You didn't pick up a newspaper when you were six years old and start reading an article on the impact tourism was having on your city. Or even 'Orphan Annie'. If you were anything like me you started playing with alphabet blocks not long after you learned to crawl. By the time you were six you knew your alphabet and went of to school. I started reading with 'Fun with Dick and Jane', then progressed to more difficult works.

One of the serious problems in electronics today is the sophistication of the hardware. When I first begin to study electronics magazines such as Popular Electronics and Radio Electronics published 'build it' projects, complete with schematic diagrams and explanations of how the circuit worked. Today the SG6841 is far more complex than the six transistor radio project I couldn't afford when I was 15.

One problem with reading schematics is the sheer volume of information contained in one 8.5 x 11 page. But you don't read an IEEE document at a glance, you break it down into paragraphs, sentences, and even words. The power supply schematic breaks down into 4 sections - input, switcher, output, and feedback. The input is fairly easy to follow, but the other three contain some complex interactions, many of which I haven't bothered to analyze.

As far as getting started, the first step is to learn the alphabet - the symbols, and how the represented component works. I use analogy and arm-waving a lot. A resistor opposes the flow of electricity. A capacitor opposes a change in voltage by storing or releasing energy. An inductor opposes a change in current by storing or releasing energy. An NPN transistor works like a dam and weir for a wterwheel. When a small amount of work is done to raise the weir a large amount of water rushes through to spin the waterwheel and grind grain, saw lumber, etc. When a small amount of current flows from the base to the emitter it allows a large amount of current to flow from the collector to the emitter. And recently I learned the an N-channel enhancement mode mosfet works pretty much the same way, except instead of emitter, base, collector they are drain, gate, and source.

I am not aware of any online sources of tutorials equivalent to 'Fun with Dick and Jane', or even Dr. Seuss. I notice that Googling schematics for dummies did bring up a number of hits.

Of course, I am usually willing to lend answers - or at least ask leading questions.

PlainBill

[Welchs101]

Re: ACER AL1713m no power

FYI: I had a 10uf cap (C857) so i replaced C857 and then powered on the monitor just to see if it would come on. I did not expect it to turn on since SG6841 is thought to be bad but thought i would go ahead and try it.

Replaced C857 and it did not turn on as......

[Welchs101]

Re: ACER AL1713m no power

ok. I did find part SG6841 on ebay.

[Welchs101]

Re: ACER AL1713m no power

Thanks Bill.

In replacing SG6841 i looked this up on digikey and could not find it. Any ideas where I could find a replacement?

[retiredcaps]

Re: ACER AL1713m no power

Tutorial time for Welchs101, retiredcaps, and anyone else.

Thanks again for the detailed explanation. I always bookmark them and re-read them over and over. I don't want to hijack this thread and get it off topic, but ...

In my area of "expertise", networking, I'm used to reading RFCs, IEEE documents and using protocol analyzers to get the correct "startup/handshaking" sequence. I know exactly what the first packet or frame looks like and what should happen next. I can solve networking problems with over 1,000 routers and switches with the help of the above mentioned.

The thing I find hard in this electronics area is the reading the schematic and understanding the various branches and their sequences. It all looks like "chicken and egg" conundrum. Any books or resources in this area to help would be appreciated.

[alexanna]

Re: ACER AL1713m no power

Thanks PlainBill
I was looking very closely at this thread, and I searched SG6841 and there was a lot of info.
And found https://www.badcaps.net/forum/showthread.php?t=11584 post #4 and, what was confusing was the voltage that was reported at pin 3 being 4.52v. So I guess that as long as some voltage is getting to pin #3 and it is lower than expected and steady, the SG controller is suspect?
Thanks again for all the info
Al.