http://www.geocities.com/sharpshark2000/monitor

And currently, to avoid the problem, I had set my picture height to 80% of the original size.

I feel your pain as my 97F is doing exactly the same thing. The issue as far as I can tell so far is a Vertical deflection issue. I am attempting to diagnose the issue but without schematics it is rather difficult just finding my way around the layout, I am really, really rusty.

If we are lucky one of the really knowledgeable techs will pop in on this thread and offer some direction. I have a good digital camera and can provide shots of the components inside and would be glad to provide images that can help others to find the correct circuits and components in question. Once I find out myself.

I am assuming the veritical IC is located on the main PCB but I haven't even identified it yet.

Greetings,

I have found the issue on my monitor and suspect that my findings can aid you in solving yours as well. I discovered 2 bad caps, in the vertical deflection circuit, C407 and C410 (both had very obvious expansion indicating failure) they are identical 470uF 25V caps and should be readily available from any electronics supplier. I have provided a digital photo of the main pcb to aid in locating the caps on the board. In the picture they are on the opposite side of the vertical IC heatsink near the HV plug from the yoke. Everything is clearly labled in the photo to orient yourself and easily find the caps.

I hope this aids others as well.

Greetings,

She is definately good to go now as C407 & C410 were exactly the issue. I managed to pickup a couple of replacements for a cost of 56 cents. My before picture looked exactly as the first picture in the thread authors original post. Here is a look at an after pic.

Wow, I must say. Though this thread was dead. I was about to buy another monitor. Woah !! It's only that?!

Thanks alot and thinking about getting a picture is very nice. Thanks! =D

Now, I have to figure out how to remove the case. The up part of the case won't take off.

Ah! got the case removed. I just forced it.

Hey, I'm currently reading the "Electrical safety" part in
http://repairfaq.ece.drexel.edu/sam/crtfaq.htm

any hint to remove the board and work safely with this NES Accusynch 90 ?

Woot! Got the mainboard removed. I though I had to disconnect the HV cable from the flyback, but I got around that: I noticed there were a ground cable connected (not soldered) to the mainboard. Good thing all these cables aren't soldered to the mainboard.

Next step: identify and replace the 2 caps you mentioned.

C407 is round on the top
C410 seems ok, but I'll replace it anyway

The one between C121 et C143 is round on top, I'll replace it. 680uF 63V

Next step: find a good electronic shop around. >_<

Okay, the store didn't have exactly a 680uF 63V, but a 80V one. The guy at the store told be that it'll be fine. I hope so.

Now I soldered the parts. It's time to get the monitor together >_< and test it on an old vcard.

The shop where I bough my stuff was a little overpriced, but...

It works !!!! It works !!!! Alleluhia !!!!

Thx to you Baseline, you saved my monitor. I was surprised that I didn't break anything while dismounting/remounting the monitor, since I'm a total newbie in monitors and it's the first complicated stuff that I dismounted.

I should get a multimeter. These things sure are very usefull to find defects. Maybe I should get into monitor repair business... nah, that's a joke. I feel more confident with computer programming. hehe

Thx again,

Christian Gagnon

Excellent I am pleased to hear that you too were able to solve your monitor issue as well. It really was rather easy once the bad caps are located.

I have this exact same problem but with the NEC Multisync 95. I was hoping to maybe base it on the schematics of the Accusync, but I'm sure the board is completely different. If anyone can tell me which caps to replace on my model and their position, I would be very grateful.

Cheers

Hi a lot of manufacturers use similar chassis in different models.

If C407 & C410 are close to the frame output IC I would change them and see.

On the MS95F, AS95F Chassis N9902F C407 and C410 are indeed in the supplies to the frame IC U401.


Rich

I was hoping that this thread would give me some sort of clue about my problem, but I guess that's not in the cards... though I have an Accusync 90, my circuit board barely resembles the one in the picture. Nowhere that I can see are C407 and C410 to be found.

All caps look good (no expansion) and there is no evidence of burning anywhere. This monitor powers up fine, last about 30 seconds, flickers green, flashes white and then does black. The power LED remains green the whole time. If I turn it off and back on, the cycle is repeated.

Any ideas?

Hey guys, I'm having the same problem as described up top .. with only 80% of the screen being usable. I was running it fine, noticing that the longer I left it on, I could slowly creep the desktop picture up to the top of the display. Suddenly, the vertical and horizontal size controls slowly change themselves, and the monitor flickers off. Slight stench of burnt something and the monitor won't show any picture now. It powers on, clicks a few times - then nothing. Going to open it up to check the caps, but any other ideas?

Well I've found that the same two caps were bulged on my monitor, but nobody in my city sells 25v 470uF caps. I can get 470uF 50v, or 220uF 25v. Figuring it was only the maximum rated voltage, I purchased a pair of the 50v 470uF ones, plopped em in and now the monitor clicks a few times when turned on, but no display and the front LED doesn't even turn on. The fuse inside is fine, all cords appear to be connected, yet nothing. Any ideas? Is it because of the capacitor I used? If so, can I use 2 220uF 25v connected in parallelin place of a 470uF one? Please someone help!

Hi as long as the voltage is higher than the origional then its only the capacitance that matters.

Make sure you fitted them with the correct polarity.

Check other undisturbed electrolytics to see the markings on the capacitor and the board.

Rich

Thank you for your response and advice! I've double-checked the polarity, and both caps are seated properly, and all other resistors, caps, etc SEEM to be ok, but without a multimeter, it's hard to know for sure. No burn-outs on the board or other direct physical evidence. The only other cap that may seem cacked is a large 400v 220uF one. It's directly lined up with the power cord socket. I can't really tell if it's bulged or not due to the large surface area on the top of it. This is my only other guess, unless another component I can't fix is toasted. BTW in my previous post I mentioned that the front LED wasn't even turning on. Upon closer inspection, I realized that when I reassembled the monitor, the LED was bent back out of place, so it DOES turn on, you just can't see that with the housing on. *oops .. I feel stupid*. Anyways, thank you once again for you advice, I'll try this last cap and after that I may have to give up and keep on using my wonderful 13" 1024x768 monitor. :| Oh, another thing - according to NEC, the MultiSync 97F only supports up to 1280x1024 ... the model I have here went all the way to 1600x1200 and higher - to 1920x1440!!! I didn't even know that resolution existed. What the hell?

Does it make the normal start up sounds but with no picture.

If you removed the video card of the end of the CRT makes sure you have no bent pins when you refiited it.

Check to see if the heaters are glowing.

Rich

Well, when I plug it into both the tower and the wall socket, it clicks as it normally would, but instead of then bringing up the picture, it clicks once more as if it were powering back off. I'm not exactly what the heaters are, but I just sat down with the monitor after reading your message, having it plugged into a working system and powered on. Nothing appeared to glow, or even heat up for that matter. The front LCD stays lit, but nothing happens. The OSD cannot be brought up either. Pushing the power buttons yields similiar results to earlier. A couple clicks to turn on, then nothing. Clicks once more to signify it's off. I've checked the polarity of the new caps, they're fine. I've checked all internal wiring, everything is reconnected properly. Even the tiny little fuse is still fine. I am truly baffled by this box of glass, plastic and silicon.