Another G07 CG0 question

[eccs19]

Guy on Fleabay has a chassis for my G07 CB0.  He claims it keeps blowing a fuse. (see link)  Any idea what would be causing this.  Would it be work buying this to replace mine that is tempermental?

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=6247447352

Best Regards

[grantspain]

blowing the fuse on power up is likely to be some sort primary fault on the mains input-eg short ptc on degauss,diode short(bridge rectifier),mains smoothing cap,transistor.
no harm in getting another chassis for parts if its cheap,whats your intermittant fault on the original?
sounds like the guy spent alot of time on this chassis though,he has changed the lopti,hot and new caps-not much else left apart from what i have previously mentioned-perhaps he has been looking in the wrong place.

[eccs19]

blowing the fuse on power up is likely to be some sort primary fault on the mains input-eg short ptc on degauss,diode short(bridge rectifier),mains smoothing cap,transistor.
no harm in getting another chassis for parts if its cheap,whats your intermittant fault on the original?
sounds like the guy spent alot of time on this chassis though,he has changed the lopti,hot and new caps-not much else left apart from what i have previously mentioned-perhaps he has been looking in the wrong place.

Link to my original problem which we were never able to solve. (Ken was a great help I might mention)

http://forum.arcadecontrols.com/index.php?topic=45704.0

[grantspain]

well cant tell you anything about mame ,but know a bit about monitors .
if i had this fault i would first change the game pcb(but you cant do that)or get a signal generator on the monitor,next using verticle size bring picture in quite a bit,then adjust horizontal hold and verticle hold to see if there is a difference.
if you had a standard arcade cab i would say this is just an adjustment issue-many monitors have adjustment pots hidden well on the chassis that are not marked for the such likes as pincushion perhaps one of these is not right,have you always had this fault or was it something that just happened?

[grantspain]

sorry just read your previous post,so your fault now is a pulse on the picture on one side-where is your isolation transformer mounted?

[eccs19]

Actually the problem is that the left side (Horizontally mounted) has a slight shake to it.  I'm not that worried about that problem, as I don't really see it when I'm playing.  The main problem is that on the right side, when it's first turned on, the picture curls up (about 1 inch on the very right).  Once it warms up, it gradually straightens out, but on the occation it will actually start to curl down.  I can adjust this with the controls for the monitor, but once it's turned off, it gets screwy again.  If memory serves me right, the curl exists even if I compress the picture. (I hope you inderstand what I mean)  Cap kit has been installed, Sync kit installed, a couple of other caps / resistors have been changed.  Have tried it with the degauzer disconnected. I think I had Ken stumped, along with a few others.  I'm open for more suggestions.  I pulled out the Pot, and tried to get a replacement, but they didn't have any in stock, but the guy checked it with his multimeter, and figured it was OK.  Hope this is not to confusing.

[grantspain]

yep got your measure,well i dont think its a pot,problem is as it warms up the problem goes-well that points to a cap,but you have changed them all.so we have to look elsewhere.i have had a similar problem with pentranic monitors which at my last company we had about 300 of-there was two problems that caused a similar fault(i know its a different chassis but most monitors suffer from similar problems).
firstly there was a smoothing cap on the frame chip circuit which was mounted near a heat sink-also there was a multitude  of unmarked pots one of which turned out to be a verticle hold pre pot,check your schematics to see if you have unmarked pots which in the schematic are explained.i am sure your problem is not as complex as you think its sound like there is an adjustment on the edge.

[eccs19]

Forgot to mention (don't know if it's important or not)  This is not mame, but actual Mr.Do! PCB.  I am waiting for one more part, then within a month should be mame.

[eccs19]

yep got your measure,well i dont think its a pot,problem is as it warms up the problem goes-well that points to a cap,but you have changed them all.so we have to look elsewhere.i have had a similar problem with pentranic monitors which at my last company we had about 300 of-there was two problems that caused a similar fault(i know its a different chassis but most monitors suffer from similar problems).
firstly there was a smoothing cap on the frame chip circuit which was mounted near a heat sink-also there was a multitude  of unmarked pots one of which turned out to be a verticle hold pre pot,check your schematics to see if you have unmarked pots which in the schematic are explained.i am sure your problem is not as complex as you think its sound like there is an adjustment on the edge.

I did check previously for any pots that were not called out (same thinking as you), and didn't find any on the main board.  There were some on the board that's on the back of the tube, but they never changed anything with that respect when I was adjusting things before.