Sanwa monitor woes

[Mr-Megalo]

been a while since I had to post in this part of the forums.
I'm hoping someone can shed some light on this, I recently bought a Sega Astro City which has the 15/24khz Sanwa monitor, I do however have a slight and no re-occuring problem. The monitor is set in 15khz mode

When I first power up the cabinet, for the 1st minute or so it sometimes makes the most horrid god-awful screeching noise (very very similar noise to 56k dial up modem noises) and then just stops. the noise is also very very very similar to the noise a monitor makes when its not sync'd (when you've twisted your Vertical so far that the screen is all wavey and broken up) even tho the screen is perfectly sync'd.

originally I thought I had fixed the problem as it stopped doing it all together, but recently I changed my JAMMA game inside (was running SFA3 on CPS2 - now running SF3.3 on CPS3) and when I powered up the next day, the screeching noise had returned.
It makes the noise when the monitor is cold, but also if I have had the machine switched on for an hour (or more) and then power it off for 10 minutes or so and power back on, the noise returns. I powered the machine up from cold this morning and there was no noise, however I powered it down and tried it again after about 30 minutes and the noise was back.

does this sound like I'm going to need a cap kit? any ideas or advice would be muchly appreciated as always
cheers chaps

[dabone]

Maybe this link will help..



http://www.arcaderestoration.com/index.asp?OPT=3&DATA=57&CBT=24



Later,
dabone

[Mr-Megalo]

dabone - thank you very much for the link, that is my exact problem so its good to know its a failry easy fix, I can get my TV guy to come round and have a look at it.

Thanks 

[Mr-Megalo]

sorry to drag up an old thread, but I've (well my TV guy) just sorted the problem on my Astro monitor

to start with all dry joints on the chassis have been addressed as there were a couple starting to show, some worse than others, also the weird high pitch noise/56k modem noise was indeed from the transformer, anyways, its all been tightened up and as mentioned dry joints have been sorted and now the monitor is crisp clear and noise free ! ! !

Man I f*&^in LOVE this cabinet  - Mad props to killercabs for supplying me with this uber peice of sexayness