K7000 blows fuses

mecha

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snatched a K7191 (think that's the model) from a T2 cab a year or so ago that didn't power up at all. I threw the kitchen sink at it replacing the HOT, VR, flyback and new caps, but didn't touch C36 or C38.

what I didn't realize when I went to test it after rebuilding was the large resistor on the side (R301?) was actually cracked in half.

I ran a continuity check on C36 and I'm getting a reading, that means it's not shorted? what, if anything, could have been damaged powering it up with R301 cracked in half? I replaced it with one from another parts chassis I have and it blew the windings off the fuse I put in it clean off. lol

please help, thank you :)
 
did you check the 6 diodes in the rectifier/degauss circuit.
and D13 - D18 also.

if you put your meeter on the beep setting and it beeps at you constantly when you measure across C37-38 something is bad.
it possibly may have blown your H.O.T again. also you put the insulator back behind your H.O.T.

also check and see if the filter cap is shorted.

if R301 was bad you may have smoked the regulator again check to see if it is shorted. and did you put the insulator back behind it.

check all that and see what you find. you may have to pull parts out of circuit to get a proper reading.
if C38, the VR the filter cap or the H.O.T is bad it can give you a false reading on other parts.

Peace
Buffett
 
I reinstalled the insulators the same way I always do lol. so I doubt it had anything to do with that.

what I'll probably do is shotgun it with all the parts you said to check from another parts chassis that were relatively new and hope it works. as I mentioned, C38 was the only part I didn't check, I for some reason didn't think it was important enough... silly me, that's a horizontal circuit part!

I wanna say I checked out all the diodes and they were fine, but I'll go over them again. I don't know what condition that chassis was in before I got that cab (that I've since auctioned off) all I know was it, like several other games I received in that trade I made, had the neckboard just hanging, so who knows if someone powered it on like that or not.
 
If you get a zero or beep reading across a cap, pull it and test again. if you still get it, it's shorted. You should not get one from one side of C36 to the other, although the four-legged kind WILL read as a short normally between the two legs on each end.

Now, go test C38...
 
yea i have around 40 untested K7000 chassis here to fix in my spare time. got most them in a lot/bulk buy from a fellow Klover.:) gives me something to do when i am Bord.
i am expecting at least half of them to need C36.


it is a very important part i have seen it bad allot.
so test it if it beeps at you its probably bad. but if the H.O.T is smoked again. you may get a false reading as they are directly connected to each other. so you may need to test C36 out of circuit along with the H.O.T.

Peace
Buffett
 
It's funny. I've done a ton of K7000's, and have only seen a handful with a shorted C36. One actually blew on me during testing. But I've seen almost every "blowing fuse" K7000 to need a C38 - and a diode or VR, too...
 
my meter doesn't beep, so do I want it to just say 1 (I think that means open right?) or do I want a .001 reading (continuity)

I know that sounds so stupid and boneheaded.. especially considering all the things I've fixed over the years now.
 
my meter doesn't beep, so do I want it to just say 1 (I think that means open right?) or do I want a .001 reading (continuity)

I know that sounds so stupid and boneheaded.. especially considering all the things I've fixed over the years now.

Actually, I believe it an l (lower-case L) meaning "overload". You do NOT want the .001 reading from one pair of legs to the other pair of legs.

Some caps will measure as a very low number (sometimes even negative) at first and then slowly climb up to the overload reading as the cap charges up from the voltage your meter is sending to it during diode/continuity test. This is fine. it's the constant .001 that is the problem...
 
Didnt get to mess with it yet, was too busy doing preventative maintenance on another K700p changing out the flyback... Got a little spooked the other day by the line fuse being blown on my MK2.

if it helps any though, the C38 gave me no continuity reading on the one this threads about. Does that mean its open and not working, and thus could be the problem?
 
you should get an ohm reading.
but not a dead short. open is a good sign.

check to see if your H.O.T to see if its shorted.

Peace
Buffett
 
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