Hantarex MTC9110, Focus Issue

[dapsaille]

Hello,

 i own an old european cab lying around for months and i'm trying to give it a refresh 

 It has a mtc9110 Hantarex chassis with an unknow monitor.

 The problem is that focus isn't stable. Sometimes i get a sharp picture (rarely) and it start decrease to a blurry picture (can't read credits) or it may start blurry, stay blurry for 2 hours than become sharper then blurry ten minutes after ...

 Sorry if my explanation is not really technical 

Capkit has been done except for the polyester capacitors that handle HV for flyback (i have them but i prefer to be sure that flyback is ok before replacing them because i've read that a falling flyback may hurt them)
Capkit has resolved some color problems but not this focus problem.

 The focus knob seems to not work or verry little, but sometimes if i put focus at max on the knob, the picture get sharp then the chassis shutdown (fan stop and no picture, security i presume ?).

 So ... do you think the Flyback can be the culprit, or the monitor itself ?
 
 I know i'm asking for a voodoo session but i'm a bit lost and don't know where to search.

 I will double check welds this afternoon but last time i've checked visually, all was ok.

Thanks for your attention

[grantspain]

its most likely the flyback transformer but you should check the focus wire into the neck socket and the neck socket itself for dirty connection in the pin housing

it is possible that the tube is on its way out but no way of knowing unless you tested it with a fully working known good chassis

[dapsaille]

Thanks for your reply 

 I've already double checked focus wire and solders, looks like i need to change Flyback (hard to find at a good price in EU).

 I will reply when change will be done.

[grantspain]

not that hard to find,i have 30 sitting on my shelf

[dapsaille]

hehe 

 i said "at a good price" in France, the only reseller that have stock sell it for about 80$ ... too much for me

 It seems that i can get an Eldor at 25$ without shipping from Italia, i'm waiting for a response from reseller, if he can send it to France, i will get two of them (i'm pretty sure that i have another mtc9110 lying around in my arcade room so .. spare is my friend ..)

 There is some of them at good price in Portugal too, and i've seen some of them in Spain, but they won't deliver to France :x
 

[grantspain]

$25 is a very good price,anything less than $50 is a good price

[dapsaille]

Ok, i've just found a reseller at 20.54€/unit + 15€ shipping fee and 21% VAT ..

 a good deal for HR7107.