Possible that the crack happened later too. Like when it sat in the warehouse or when my buddy pulled the yoke. The arcing was inside the neck and puff of smoke came right off a spark gap on the neck board.
- Thread starter nem
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Hatsune Mike
Champion
Well, letting gas in is a pretty good way to cause HV arcing to places inside the tube, so I wouldn't be surprised if subtle physical damage was step 1. It could have been a small fissure that finally had enough.
This is an interesting thread. Would seem unlikely for chassis to be killing tubes especially physically blowing glass apart but if multiple people have the same issue it would be nice to see resolve. Where root problem exist.
from what though? that is result of problem not root of problem.
the flyback fails internally and sends the hv to unknown levels, I have not seen it blow the end of a tube off but i have heard reports from others that it does this.
I have seen a few fail to the point of excessive hv and the noise is quite disturbing, lucky I had no tube damage on these occasions
I have seen a few fail to the point of excessive hv and the noise is quite disturbing, lucky I had no tube damage on these occasions
Well, shit. Happens with a Toshiba PF too (PB9929).
Had no problems with this monitor before this. Then one day, no image, heard clicking from the chassis. Turned off the cab, was taking off the neckboard when I noticed there was movement in the neck. Ruh roh.
There's a post in a different thread here by @Hatsune Mike explaining why this possibly happens on newer tubes.
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Those chassis are use and scrap, on the main there is little board placed vertically it should control the hv but if something go wrong in this little bastard, the Cassis just kill the the tube in one sec , releasing itself in "overload protection" Or in the worst case just ready to destroy another next tube!!!
You will never be able to repair this little board and also you should not risk to destroy another tube!
You will never be able to repair this little board and also you should not risk to destroy another tube!
jimmyjames
Professional
Ive been looking at a replacement yoke and chassis solution but nothing good yet I tried a ms9-29 I got it to work but wasn’t happy. Chassis wise I’ve used Ms2932, ms2934 not happy with either. Blast is trash anyway, imo it’s my least favorite of all my cabs and I have a few.
Its a long story, in short, the reason of the death of those tubes is caused by the materials used to assemble the tube itsef, at late of 90' some materials gone out of low and thats why the chassis destroy the tube, basically due to this, there is a G1 leackeage and in the same time the HV control on the chassis become crazy and a blue lightning through the entire kinescope , the chassis may remain in protection state or with HV-Overload pcb in not working condition just ready to destroy another tube.
The same happned to the late professional broadcastting monitor from sony, BVMs D series and late production of BVMs F1 and A series, Back in the Day In our shop (autorized sony service) we just replaced both Tube, defelction board and PA board the one wich control the HV (those monitors are modular) and at that time we serviced lots of BVMs with 100.000 hours of usage wich had all minor issues but not with fryed tube those ones were all produced earlier. Some of the later production like the D32 was at 40KUSD! those ones often failed even after 10.000 hours , we still have in stock lots of those tubes still boxed l
On the Blast you can put a nanao MS9 with Hitachi tube, it should fit flawlessly and surely will be way reliable.
The same happned to the late professional broadcastting monitor from sony, BVMs D series and late production of BVMs F1 and A series, Back in the Day In our shop (autorized sony service) we just replaced both Tube, defelction board and PA board the one wich control the HV (those monitors are modular) and at that time we serviced lots of BVMs with 100.000 hours of usage wich had all minor issues but not with fryed tube those ones were all produced earlier. Some of the later production like the D32 was at 40KUSD! those ones often failed even after 10.000 hours , we still have in stock lots of those tubes still boxed l
On the Blast you can put a nanao MS9 with Hitachi tube, it should fit flawlessly and surely will be way reliable.
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Its a long story, in short, the reason of the death of those tubes is caused by the materials used to assemble the tube itsef, at late of 90' some materials gone out of low and thats why the chassis destroy the tube, basically due to this, there is a G1 leackeage and in the same time the HV control on the chassis become crazy and a blue lightning through the entire kinescope , the chassis may remain in protection state or with HV-Overload pcb in not working condition just ready to destroy another tube.
The same happned to the late professional broadcastting monitor from sony, BVMs D series and late production of BVMs F1 and A series, Back in the Day In our shop (autorized sony service) we just replaced both Tube, defelction board and PA board the one wich control the HV (those monitors are modular) and at the time we serviced lots of BVMs with 100.000 hours of usage wich had all minor issues but not with fryed tube those ones were all produced earlier. Some of the later production like the D32 was at 40KUSD! those ones often failed even after 10.000 hours , we still have in stock lots of those tubes still boxed l
On the Blast you can put a nanao MS9 with Hitachi tube, it should fit flawlessly and surely will be way reliable.
So it is the tube not the chassis that is causing the CRT to go to air?
Neck board from chassis from what I can gather
The chassis is definitely involved. My Blast tube blew when the faulty Yaton chassis was attached to it.
I think the point being made is that it only happens on newer tubes, not old ones. I've never heard of a A68KJU96X ever blowing up.
I think the point being made is that it only happens on newer tubes, not old ones. I've never heard of a A68KJU96X ever blowing up.
They surely removed that chassis from a tube with sight g1 leakeage, in this condition the monitor works but with some flicker on bright white-flash at full screen due to the hv starting to violently increase, this condition will last few minutes or hours then the whole monitor autodestroy, some of those tubes just loose emission at cathodes , the chassis will last longer but with an unacceptable dimm picture, poor contrast no decent white level.
And yes the chassis was the most advanced one ever made by Nanao simply do not match with the so fragile Toshiba tubes of its later production, the weirdest its that Orion acquired all Toshibas patents to make 29" Tubes also for arcade but those tubes are very reliable.
About Sony BVMs pro monitors later production, Sony engineers said us to not try to repair the faulty PA board risking to destroy a New tube wich was high expencive but just replace both PA board and Tube then after Years they "addressed" the issue with a New firmware wich basically reduced the beam level, the white-contrat was still very good but never Magical like before the firmware update. Also I remember that they claimed the PA board was just impossible to repair only scrap, after a death of the tube.
Interestingly enough, I have some Blast City compatible Orion 29" tubes handy and have a spare MS2933 chassis to pair with it. Will get to pairing them together soon. Woot!
