WG k7000 and k4900

[sp0rk]

I have two monitors that suddenly have gone 'dead' on me.

1st - the 4900 - it was always a great monitor, worked for a long time.  I bought a TV alignment kit, because the horizontal picture was WAY over the edges.  the alignment didn't do much.  I had to take the chassis off the frame in order to get at the horizontal coil, and when I did, my picture went to a single long line (i have it set as a horizontal picture).  I foundt hat the two pins came loose from the neck to the board, when I pushed them back in, the picture came up fine.  Then, I twisted the coil a couple more clicks just to see if it would do anything.  When I turend the montior on, I get nothing.  No picutre.  Not even the thin line.  I checked all the cords, and they seem to be plugged in.  Did I somehow break the coil? 

2nd - I decided to replace this monitor with a WG k7000 that I had sitting arround.  I plugged it in, and all I get is smoke.  This monitor was working at one point, but I get no picutre, nothing, just some smoke.  The only thing that looks out of place is the setting where the anode cap comes connected to the board looks like it might be 'loose'.  I didn't try to push it down or anything, I'm not even sure if it's soldered on the board.  Could this have anything to do with it, or is my monitor just screwed?

If anyone has any ideas what could be easy fixes, I'm all ears.  For now, I'm just going to cap a working TM202G I have and use that.  I'd like to fix these, but if I can't, I'll just buy replacement chassis from alva.  It's cheaper, and less hassle.  Maybee it's something stuipd I'm missing though. 

Thanks!

[Q*Bert_OP]

Examen the flyback on the 7000. Is it cracked or burned(smoked)?

[Ken Layton]

The 4900 is well known for tons of bad solder joints.

The 7000 also has bad solder joints, just not as bad as the 4900. On the 7000 closely examine under a magnifier the connections at resistors R101 and R89. The original flybacks on the 7000 fail all the time. Penn-Ray.com has the flyback on sale in the latest sales flyer (you need to download it from their site) for dirt cheap (mention the salesflyer price to get the sale price!).

[sp0rk]

thanks guys. 

I will check them out after New Year's when I get a chance and let you know what I find.

I think it will end up being cheaper / worth it to get replacement chassis instead of repair them.  I think they are like $45 at alva last time I priced. 

[censei]

The CGA Wei-ya chassis are crappy, they don't have contrast adjustment! 

[Ken Layton]

I'm sorry, I beg to disagree. The Wei-ya chassis is good. The Jen Shinn chassis is crappy.

There's a lot of classic monitors that don't have contrast controls: Wells 4900, 4600, Electrohome G07, etc. The contrast control on a Wells 7000 is nothing but trouble IMO and monitors should be made without them.

Remember that when ordering a replacement chassis, the 7000 and the 4900 are different vertical impedances on the yokes. The 7000 is low impedance while the 4900 is high impedance. Remember also that while flybacks for the 7000 are plentiful (and often on sale like at Penn-Ray right now for $16) the flybacks for the 4900 were discontinued years ago and nobody makes a replacement flyback for it. So if a flyback problem is suspected on a 4900, a replacement chassis is the only option.

[censei]

wei-ya chassis for classic games (pacman, galaga, stargate, etc...) are good but for anything newier like street fighter, neo-geo, or mortal kombat, it's going to give one ugly picture because of not having contrast.

[sp0rk]

http://yp.bellsouth.com/sites/alvaamusement/

I don't see where it mentions anything about vertical impedances on thier order area.

The 7000 is what I will probably buy a replacement for, it's an 8-pin wells.  As long as I get that 8-pin, it should be fine, right?

(and I already have a wei-ya chassis for an electrohome.  I've been happy with it so far, and have played strikers 1945 and bubble memories on it)

[Ken Layton]

For the 8 pin k7000 you want the 1220-S chassis. You'll find cheaper prices on Alva's other website: http://alvaamusement.com

[sp0rk]

Just want to say - I finally got arround to ordering the replacement chassis, and I'm incredibly happy!  Alva shipped to me in arround 4 days.

I had two wells k7000 that I replaced, one was dead the other had some screen problems.  Both turned out great!  One of them is super, its by far the nicest looking monitor I have.  The other turned out ok, but is a little 'bright', I think it might be the tube, because it was kind of washed out on the wells k7000 as well, although it is much better now.

thanks for all your help! 

[Ken Layton]

Glad to hear it worked out ok. Were you happy with the prices from Alva?

[sp0rk]

Definatly.  It was $113 for both chassis shipped.  Not too bad considering they are in florida and I'm in michigan.  I will definatly turn to them for monitor chassis in the future.