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Thanks for the reply - couldn't see any electrolytic caps.
I've traced from the PWM pin 7 - which according to the datasheet is VCC.
From there i can see an PCB latch plug. I guess its unpluged at manufacturing but does give me "easy access" to powering the PWM externally.
On the otherside of...
Hi
Im new to repairing switch mode power supplies - so excuse my terminology.
I have two SMPS, one looks to be fairly complex and before i try to tackle that one i'd thought i'd start on the easier one.
The story is - it came out of a external USB drive. The SMPS supply looks pretty...
BRIAN YOUR A GENIUS....
IT WORKED..
I placed the CRO on its side - the right side down - thinking what ever is obstructing is probably pushing to far left from the right side - banged the table and it move - happy days.
Banged the table some more - it moved some more - and now i have a...
Thanks Brian,
Very much appreciate your time & input.
i kinda felt that it was the CRT. I actually found someone still selling a new CRT for about $130AUS + delivery - i don't know if that's allot for a tube - but since i blew up my multimedia worth $800 (bought 25 years ago) - in retrospect...
Thanks Peter,
Thats awesome - same here - happy to make some measurements too.
PS: i might actually call on that favour ;-)
Im currently having another issue with this CRO - which is ensuring my horizontal trace makes all the way to the right.. Theres another thread/post open at the moment...
ok - i've swapped the x plate connections to the CRT and found no change at all. ie: i still had clipping on the right side. I've then pulled out the CRT hoping to see if i can see something but the entire tube is covered with an anti-magnetic shield.
In otherwords the glass tube is lodged...
@betwixt - doh! swapping the x plate connections is a great idea - why i didnt think of that.. Will try that - and report back - thanks :-)
That will confirm if its electrical (circuit) or physical.
@burt007 - thanks for your reply - but its not the probe(s). I should be able to move/adjust...
Thanks for the response.
@BradtheRad - i'll check but generally i haven't heard anything rattle and i've had the CRO on it side, upside down, etc while measuring voltages. If i'd have to guess i say i'd lean towards the disc ending sharply.
While the disk is in the "middle" of the screen it...
Hi,
i can't figure this one out - any input will be appreciated - last time the response was great and ended up repairing my focus issue.
The Problem
My max horizontal defection doesnt 'deflect' across the screen. The trace cuts short on the right by -2.5mm from the right edge of the grid -...
i've checked the voltages with a multimeter - and after some minor adjustments - they're perfect. Adjusted the -15v rail also adjusted the 15 and the -14.5. Also adjusted the 100v. All good - i swear.
....but i think thats whats happening - its shifted the display sideways. Instead of the...
:lol:
Yea checked that. And im tripple checking everything i post now.
Adjusting the x position to the left - moves the entire scan to the left side and "off" the screen (perfect), however when i move it to the right it clips.
It clips 2.5mm short of the end of the grid - let alone scrolling...
SUCCESS - ITS FIXED - See pic.
synopsis
Ok long story short R77 was open circuited. Replacing R77 fixed it.
E-design your the man although i admit i led everyone astray with my "facts".
So basically i must of stuffed up and couldn't measure resisters if my life depended on it. :-)...
yup, placing a 2M2 resister on pin 8 to ground reduced my 10 scan lines to about 5 of them.
......and i blew up my TES-2360 multimeter (that one hurts) doh!
im going to replace the entire series of resisters & POT. (and multimeter)
thanks guys,
Yea, now that you mention changing the electrolytic caps - seems pretty obvious now. Even if there not entirely the fault it can't hurt. First thing they say in those article about "restoring vintage radios". (derrr)
I've ordered them in - there barrel shaped electrolytic and so...
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