WG6100 blows F100 & F101 on powerup

scottz29

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Just completed my 6100 rebuild. Did the Zanen cap kit, the 'extra parts' kit from the 6100 FAQ (ordered parts myself from mouser), and installed an LV2000.

When I power the game on, F100 and F101 blow immediately.

I did replace the chassis transistors, but I've checked several times and none of the collectors are shorted to the chassis. Also took several good pictures before disassembly, and everything seems to be connected properly.

I also smoke-tested the deflection board by connecting it independently, and it worked fine -- LV2000 powered up, verified all my voltages and no fuses blew.

Help!
 
I had a space duel do that,it ended up needing the edge connector on the pcb cleaned.The game played blind so I never checked it until I tried everything else.
 
Apparently you put the mica insulators between all 6 of the transistors and the frames?

Well, the first thing you do is unplug P100, P600, and P700 to see if it still blows. If it does, then I'd check around your LV2000 installation to make sure you did it right or if there's a solder bridge leftover when you were removing parts. Might check those diodes there by the big caps, too.

if it doesn't, then check Q102 and Q103 to make sure there isn't a short there somewhere (even if it isn't on the collector).

If the fuse doesn't blow and everything still looks good, plug in P100 and see if the fuse blows. If so, check those transistors in the back - Q603, Q605, Q606, Q703, Q705, Q706 - and the diode nearby each...
 
I just tried that, and same result + magic smoke. I presume the magic smoke is from R106 which is in the degauss circuit?

I'm running out of fuses, and this is somewhat discouraging at this point. I figured it was a transistor problem on my part, but I believe those three connectors take the major transistors out of the equation.

After I installed my LV2000 and capped my deflection board, I hooked that board up independently (per the LV2000 instructions) to test voltages. I didn't blow any fuses at that point.

Now I'm really stuck.
 
Try measuring your voltages from your power brick. If you're getting the wrong voltage it would blow up. Try disconnecting your HV unit and see if the deflection board fuses blow up...
 
I was able to squeeze off one more quick test before leaving for work this morning. Disconnected the connector from the HV cage (P900), fired up the game, and still blew F100 AND F101 immediately.

The only thing left connected to the deflection board at this point is P101 and P701...

I'll disconnect the rest, and test again. But I've tested the deflection board by itself once before and no fuses blew.

Any more ideas? This is getting frustrating.
 
I was able to squeeze off one more quick test before leaving for work this morning. Disconnected the connector from the HV cage (P900), fired up the game, and still blew F100 AND F101 immediately.

The only thing left connected to the deflection board at this point is P101 and P701...

I'll disconnect the rest, and test again. But I've tested the deflection board by itself once before and no fuses blew.

Any more ideas? This is getting frustrating.

If you fried the chassis mount transistors, you may have to disconnect those last two connectors in order to bring it up without blowing fuses.
 
Well, I finally picked up a multimeter with a diode setting. Not sure how I got along without it.

Anyway, apparently whatever caused the circuit to blow when I hooked everything up, it took out my LV2000 board, and a bunch of transistors and diodes on my deflection board. All 6 frame mounted transistors still tested good.

Both transistors and all the diodes on the LV2000 are toast, D100-103 are toast, and Q603 and Q703 are toast.

As I said, I tested the deflection board by itself right after I finished rebuilding it and it worked fine. Something caused this failure after I connected everything. I noticed the BU207 bottle-cap transistor mounted on the HV cage was shorted. Could this have caused the whole thing?

Now, after I connect P701 (from neck) and P101 (from HV cage/chassis ground screw) the following pins short (steady beep on conductivity test) to the chassis:

pin 6 of P100 (which is supposed to give me my -26v)
pin 5&6 of P700, and P800

I am assuming this the result of all the shorted components?
 
Well, I finally picked up a multimeter with a diode setting. Not sure how I got along without it.

Anyway, apparently whatever caused the circuit to blow when I hooked everything up, it took out my LV2000 board, and a bunch of transistors and diodes on my deflection board. All 6 frame mounted transistors still tested good.

Both transistors and all the diodes on the LV2000 are toast, D100-103 are toast, and Q603 and Q703 are toast.

As I said, I tested the deflection board by itself right after I finished rebuilding it and it worked fine. Something caused this failure after I connected everything. I noticed the BU207 bottle-cap transistor mounted on the HV cage was shorted. Could this have caused the whole thing?

Now, after I connect P701 (from neck) and P101 (from HV cage/chassis ground screw) the following pins short (steady beep on conductivity test) to the chassis:

pin 6 of P100 (which is supposed to give me my -26v)
pin 5&6 of P700, and P800

I am assuming this the result of all the shorted components?

All of that shouldn't be grounded to the chassis as you know. You probably have a short somewhere that is not in a component. Check all the connections, sloppy solder joints, etc. Don't forget to check the HV cage and neck boards too since once you connect those it could ground the deflection PCB if the short existed on the other side of the connection. Given that you did the LV2000 install and it was working before being connected, I would actually start with the other boards.
 
One other thing my silly ass has realized in the meantime....today I carefully read Bob Roberts' page on the 6100 additional parts kit (http://therealbobroberts.net/k6100xlyot.html). He mentions that the WG 6100 FAQ document incorrectly recommends a 1N4007 rectifier diode for D100-103. Can someone please update this?

As I did not purchase Bob's kit (I don't believe it was in existence at the time I ordered all these parts), I ordered the Zanen "get well" kit, and ordered the additional parts from Mouser myself (this game has been in storage for several years and I'm just getting around to fixing it now). So, unwittingly I installed 1N4007's at D100-103, and are now toast obviously due to the fact that are severely underrated for that circuit.

Well, I've ordered the (correct) replacement parts...I will redo my continuity tests and post results in a couple days. The continuity to the chassis on those pins really has me stumped.

Thanks for everybody's help so far. You guys all rock.
 
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Ok, finished repairing the blown deflection board. Things seem to be working properly. Among lots of other fried stuff, I had a blown diode on my LV2000 which was shorting alot of connector pins to ground.

2 questions:

  • Pin 2 & 3 (blue & yellow) on connector P701 (yoke connector I believe) are each still shorted to ground (and therefore shorted together). Normal or not?

  • Is it ok for the collector on Q603,604,703,704 to be shorted to the heatsink? I didn't put in mica insulators, since there weren't any to begin with. The heatsinks aren't anywhere in circuit, so I didn't think this was a big deal, but wanted to check anyway.
Assuming this is all good, I'll test the deflection board separately, and verify my +-26v. Assuming that tests out, is there any good way to test the HV cage separately also? I don't want to go through this again.........
 

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Pin 2 & 3 (blue & yellow) on connector P701 (yoke connector I believe) are each still shorted to ground (and therefore shorted together). Normal or not?

Both 2 and 3 go to ground through a 1.5-ohm resistor each. So, while it reads as a short, if you switch over to resistance test, you'll probably get a reading of about 3-ohms.

Is it ok for the collector on Q603,604,703,704 to be shorted to the heatsink? I didn't put in mica insulators, since there weren't any to begin with. The heatsinks aren't anywhere in circuit, so I didn't think this was a big deal, but wanted to check anyway.

Yes, that's fine.

is there any good way to test the HV cage separately also? I don't want to go through this again.........

Not really. Inspect it for burnt diodes (you can test the too) first, before you power up. Also, the orange wire on the HV cage connector goes to the neckboard. Where it attaches to the neckboard is the spot to measure your B+. It should read +180vdc. Adjust the pot in the center of the HV cage if it's not. Use a long plastic screwdriver to adjust it...
 
Ok good news, I got the deflection board rebuilt, LV2000 board lights up and I have my +-26v on pins 3 & 6 of P100.

Now should I proceed by just putting the entire monitor back together and connecting up everything, or should I plug connectors in one by one and test after each connection?

If the latter, in what order should I connect? I just want to proceed with caution this time, so if something does go wrong, I can at least tell the point at which it did.
 
Ok good news, I got the deflection board rebuilt, LV2000 board lights up and I have my +-26v on pins 3 & 6 of P100.

Now should I proceed by just putting the entire monitor back together and connecting up everything, or should I plug connectors in one by one and test after each connection?

If the latter, in what order should I connect? I just want to proceed with caution this time, so if something does go wrong, I can at least tell the point at which it did.

I would test all of the transistors if you have not before connecting them to the deflection board. If they are all Ok, I would just connect them all then test. If that goes well, I would just hookup everything else since at that point it is just the neck board and HV cage your adding.

You might wait to see if anyone's got a difference of opinion, but that is how
I would do it.

-VJ
 
Update...
Gone over the HV cage with a fine tooth comb. After replacing a few questionable parts, I'm still getting 'short' readings.

Namely the BU207 bottlecap transistor mounted to the HV frame. I get continuity between the base/emitter, only when the transistor is installed. I tested it out of circuit and it's fine. Collector is not shorted to the frame.

Same thing for a few other diodes on the board - they read bad in circuit, but test fine when I pull one leg.

wtf is going on?
 
Update...
Gone over the HV cage with a fine tooth comb. After replacing a few questionable parts, I'm still getting 'short' readings.

Namely the BU207 bottlecap transistor mounted to the HV frame. I get continuity between the base/emitter, only when the transistor is installed. I tested it out of circuit and it's fine. Collector is not shorted to the frame.

Same thing for a few other diodes on the board - they read bad in circuit, but test fine when I pull one leg.

wtf is going on?

Parts can read bad in circuit due to the characteristics of the circuit itself. That is why you have to pull them out and re-test when they are bad in circuit. A simple example is resistors. When you measure a low Ohm resistor in circuit, you almost always get a good measurement. If you measure a high-value resistor in circuit, allot of times it won't read correctly because there is another path through the circuit with less resistance between the two points your touching the probes.

Is there proper insulation on those cage mount transistors? Did you pull the cage out from the monitor, or is it hooked up in the monitor during your tests?
 
I am testing the hv cage separately. True about resistors but should a base/emitter test on a transistor register as shorted? That definitely seems not right. Not sure where to go from here.
 
Remember there is a transformer on that HV board - the flyback, remember? You're probably reading your "short" through the flyback windings.

If you think it's fixed, hook it all up and see what happens...
 
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