Hantarex Polo 28 25KHz Hissing & Cracking - Flyback problem?

[mentalmike]

Hi, after a bit of advice. I bought a twin Daytona sit down cabinet back in 2010 with no game boards - UK spec 240V. I started to restore the cabs and had the monitor working in one of the cabs no problem - the other I haven't tried as I am still to work out what's in it but that's for another post. I never finished back then and the units have sat unused in my garage and then moved to my new house. I have now started again, thinking everything would be ok with this cab I turned the monitor on, after a couple of seconds it is crackling loudly and then hissing. I have done a bit of googling and found a post on here that seemed to sound very similar. I have since taken the monitor out of the cabinet to take a proper look. The flyback looks in great condition - just dirty.

Here are some pics

















Could all it need is a good clean? I want to try and avoid causing any damage more than I might have as when I last switched it on the pic was great. Should I try cleaning and then switch on or should I do anything else? I've read that seeing as I've got the monitor out I should re cap? Should I test anything? I have never worked on a monitor before so apologies if I have asked anything stupid or used terms incorrectly, just don't want to cause any damage!

Any advice much appreciated!

[grantspain]

it will be one of three things,

dirt/damp around anode cap-clean with delicate cleaning agent,possibly a little glass cleaner-do not get any into the hole and do not whatever you do remove the anti corona dope(thats the red-ish paint)
clean the cap itself and all along anode cable
dry off completely and use a hairdryer from distance if need be-not too close and not too hot

flyback tansformer may have developed a hole-if this is the case then a new flyback with be required

tube neck could be cracked-if this is the case then a replacement tube is required

easy way to prove what is at fault-power on cab in the dark and see where the arc is coming from,don't leave it on for too long though

[mentalmike]

Thanks for the reply!

Is isopropyl ok to use for cleaning? Does the paint look ok from the pic?

I'll give the cleaning ago tonight when I get in from work and check the tube for cracks - hopefully not this! Does everything else look ok from the pics? Do I need to worry about doing a cap kit or leave that for the future?

Sorry for all the questions!

[grantspain]

i do not know whether isopropyl will be too strong and remove the anti corona dope,you must have some glass/window cleaner

everything else looks ok

you will know if the tube is broken as when you power on you will get a purple firework display in the neck

polo rarely need many caps and they would never cause the problem anyway,get the machine running before considering preventative measures like monitor service

[mentalmike]

I think I have a better idea of what is wrong. Cleaned everything up, but still have the hissing - doesn't seem quite as bad. I tried it with the lights of and can see purple coming from the cap so its leaking. Any ideas how I can stop this? There is what seems a residue from where the cap may have been stuck on at one point

[grantspain]

now you have one of two issues,either the eht is too high due to chassis fault or it is just damp

another point to make is that the tube has not been operated for a long time so will need to run for a fair few hours

[mentalmike]

Thanks for your help - in the end I tried some Servisol Silicone Grease and that seems to have done the job!