WG k7000 issues

starfighter2

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I have a Wells Gardner k7000 standard CGA monitor, think its a 19k7610 that i am trying to get running. It has new caps and flyback. At one point It would not turn on at all(no crackling of the monitor). I had a High reading on the ceramic resistor R301. I followed the Randy Fromm instructions but removing the shut of diode, and Q11 was still high +170 volts. the flow diagram indicated that it was a horizontal failure so I replaced IC4(STR3123), Q11 (2SD1398), and IC2(LA7823).

Know what happens is I hear the monitor start up(can hear the crackle of the monitor) but after about 2-3 seconds the fuse will blow and it will short Q11. I replace Q11 and the fuse, make sure that the middle leg of that componet is not shorted to the chases, turn the monitor on and hear it start up agin for a bout 2-3 seconds. But again it will blow the fuse and then short Q11 again.

Anyone have any ideas as to what is going on with this monitor?
 
in my opinion you replaced parts that may have not been bad.

the problem with the chart is that it does not tell you how to check a part.

check all of your work for solder bridges.

also check all of the caps to verify they are in the correct way.

you did not use arctic silver on any of the new parts you installed and on the VR and the H.O.T. you put in the insulators correct.

if you did it will blow the fuse. that is a conductive paste and should never be used for anything in this hobby.

check R101 on both legs to verify the pads and solder are not cracked.

Peace
Buffett
 
I will look at the caps since I did not replace them, They look like they where released recently. I did not use arctic silver just the insulators and did a continuity test to ensure that the middle leg is not connected to the chassis. the outer two are. Is that correct? R101 does not appear to be bad. Any other ideas?
 
test the H.O.T. as shown in this video.



did you wiggle R101 to see if the pads moved on the solder side.
it can look good but the pads/solder can be cracked.

if either side of R101 is not rite the chassis will never fire up.
give it the wiggle test and a continuity check.

a pic of the chassis will tell us if it has been capped or not.

plus a good re-flow of the chassis from the fuse to the flyback is needed and is what i do on every repair.

also make sure C57 is in there correct. it will give the fuse several seconds before it blows. if it is not correct replace it as it is damaged.
wile you have it out check all the caps to be sure they are all in correct.


Peace
Buffett
 
Got a little closer. At this point I hear the monitor start up with the crackeling noise. It will stay on with out bowing a fuse or q11. But there is no raster buy turning up the screen control and if I try to discharge the second anode with a high voltage meter, there is no pop and the meter does no show any voltage. This seems stage since I hear the crackeling when I start the monitor. I changed q11, ic1, the flyback, and resoldered 2 lose componets. I have a working classes and compared the major componets to make sure they where all close in readingand that there was not any componet unnessisarily grounded. I did not test every single componet yet.

Any ideas for next steps?
 
just because you hear the static in the beginning does not mean it is not kicking back off in a second or two.

pull one leg of D10 and see if the monitor fires up.

if it does you have a faulty VR.

if it does not then you still have a cold solder joint, broken trace or another part shorted and keeping it in HV shutdown.

Peace
Buffett
 
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