UPDATED Project - Kortek KT2932F - Powering on now, Very Weak Horizontal.

[NightWolfx03]

I have a Kortek KT2932F I am looking at, the horizontal width got screwy, so I was trying to see if something came loose in the monitor, a gentle tap on the frame and I got smoke and sparks from what appears to be the horizontal coil. I need to find a schematic for this board as well as see if I can find this coil ( right now all I can see is that it's not adjustable and has 7R5 printed on top ). The only question is that I have, since I am still learning, is that do coils just go bad or did something else cause this thing to cook? The monitor was running ( with a messed up picture) until the coil arced out.

~Night

UPDATE:

Go to my latest post, I have got the monitor to turn on now without the fireworks show.

[grantspain]

seen it happen with wg d9400,the horizontal drive transformer shorts out and takes a few components out also-bad manufacturing imo
post a photo of the coil
not worked on a 2932 but have worked on a fair few 2914-not sure if the layout is the same

[NightWolfx03]

Here's pictures of it

[grantspain]

that looks to be poor manufacturing
that is a completely different chassis to the 2914f

http://www.casinotech.com/kortek/tech_docs/info_tech_docs/parts_lists/KT2932_old_version.xls

not sure if thats correct version but it has coils and their values listed along with the position number on the circuit board

[NightWolfx03]

Hmm, not seeing it.  On this board it's in position L304. The heat shrink on the outside of the coil reads KE and the top of it reads 7R5. I also notice it does appear to have 2 separate coils, the thinner coil at the top seems to run back into the logic / processing side of the board, maybe it's for feedback or adjustment ?

[grantspain]

same coil is used on 2914f at position L701 on the schems

might be worth seeing if betson or suzohapp have this part

[NightWolfx03]

Seems like Kortek stopped making these coils. Now I'm stuck on a search for new old stock Linearity coils. So far, Suzo-Happ and Shaffer have told me I might just have to scrap the monitor or find a parts chassis.


BLEH 


I am partially tempted to, if it gets close to looking like scrap, maybe find some enameled type wire and try to rewind the part of the coil that shorted, for S**ts and Giggles.

[MonMotha]

I'm guessing you don't happen to have any specs on the thing?  Just a Kortek part number is of course kinda useless, but if you have actual specs, you may be able to match it to something you can actually buy.  I know of at least one smallish shop that still makes standard/stock linearity coils.  If indeed it's the exact same thing as a KT-2914F, I have a non-working unit (hope to make it work, but right now it's dead so I don't mind potentially making it deader) I can try to measure for you.

[NightWolfx03]

Well happ has the coil listed I think. 7R5 is apparently 7.5 uH. However, this coil has another coil on top, either I think for feedback or probably more to allow the control to adjust the screen. So I don;t know if a normal one would work on not.

[MonMotha]

Yeah, it's a dynamic linearity coil.  These are what lets the monitor adjust the linearity from within the OSD menus.

PREM has a selection of these that I think they still sell.  If you can't get something suitable from Happ, check theirs out:  http://www.premmagnetics.com/CRT

[NightWolfx03]

Happily after a few days Casinotech got back to me and they still have these coils for $5.95 so I am going to order 2 of them. Hopefully now, that coil was all that's wrong with my chassis. Though I might try and double check surrounding components as well. If there's anything that should be checked, lemme know so I don't burn up another coil. As I said still learning and help is always appreciated

~night

[NightWolfx03]

Well I got the coil in and tried to fire it up and I got a light show from the chassis, I think I have a resistor that is arcing / open. It's burnt to a crisp so I need to find out what it's value was. When the arcing stopped for a moment I got high voltage just as I was shutting it off. So I think it was running for a tiny tiny bit before I pulled the plug.

The Resistors R312 and R316 burnt and I cannot tell their values, I suspect I need to replace the diodes that are next to them as well, D304 and D305. And possibly the semiconductor device they are feeding that looks to be Q314.

If anyone knows what these parts are, that's be a big help.

I tested out most of the caps in the surrounding area and they seem fine, including the metal film / mylar ones.

Here's some pictures of where the light show occurred it also had a wonderful bouquet.

[NightWolfx03]

Another update.

Checking about I think I might have found another issue. Q314 ( IRF840 ) is showing 2.5 Ohms between the gate and the Source. And it shows 200 ohms between the gate and drain and the source and drain. I think it might just be shorted. So I am going to replace it. I am looking at the schematic for the 2938 monitor as I have not found the one for the 2932 ( most of the parts are close if not a match in rating)  I also wonder if I should check the SMPS controller, KA3883C that is controlling the IRF840 or if it's only going to be isolated to the IRF840. I am also going to replace the burnt resistors and the 2 diodes that are part of that network.

Any ideas throw them at me

[NightWolfx03]

Also replacing the 2 fusible resistors there as well, both that were hooked to the IRF840 are open circuit.   Looks like this thing went to town all over itself.

[NightWolfx03]

Ok, back to the Kortek.

I got it to power on, no smoke and fire this time, however I don't have much if any horizontal on the screen.

I have included a picture, any ideas where I should look next ?


I'm still learning and the kortek chassis is not familiar to me like the Wells ones are.