no power I get nothing over 3v much past the plug. there was a small white cube that look very melted. no marking on it. seems to have infinite resitance.
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12" Macintosh Monochrome CRT monitor
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Re: 12" Macintosh Monochrome CRT monitor
Where is this part located in the monitor?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: 12" Macintosh Monochrome CRT monitor
12" macintosh monochrome monitor
the part is right behind the power plug, the the Hot side of the plug first goes thru a large resistor then to this.
This is an old monitor the only reason I am trying to fix it is it is parts of a display for a museum and can't easily be replaced
the fuse is intactLast edited by Larry Offley; 05-05-2016, 07:17 PM.
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Re: 12" Macintosh Monochrome CRT monitor
Its most likley a current inrush thermister NTC. Is it in line with the ac circuit, are there any board markings for it (ie ntc1 or th602) it be could be connected between the ac line in and the bridge rectifier ac in.
If you open the white plastic there should be a disc between two metal contacts, you could try measuring the the disc, it should be around 3-5 ohms cold.Last edited by R_J; 05-12-2016, 05:50 PM.
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Re: 12" Macintosh Monochrome CRT monitor
Originally posted by stj View Postcheck the circuit boards for any name or model number that could be searched.
it's very unlikely that it was made by apple - probably made for them buy someone like NEC
numbers on the board
630-0001-a
820-0258-e (that looks like the board numbers they still use)
it says apple computer systems on the board
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Re: 12" Macintosh Monochrome CRT monitor
Originally posted by R_J View PostIts most likley a current inrush thermister NTC. Is it in line with the ac circuit, are there any board markings for it (ie ntc1 or th602) it be could be connected between the ac line in and the bridge rectifier ac in.
If you open the white plastic there should be a disc between two metal contacts, you could try measuring the the disc, it should be around 3-5 ohms cold.
all of the resistors and caps have marking next to them but nothing next to this.Last edited by Larry Offley; 05-12-2016, 06:24 PM.
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Re: 12" Macintosh Monochrome CRT monitor
This is a schematic I have of an apple color monitor that shows the th602 thermistor, I suspect the mono monitor has a silmilar ac input circuit.
If you ignore the degaussing circuit. you can see where your thermistor would be located, It that is it you could place a short (piece of wire) in its place just to check the monitor, but don't leave it that way as it would eventually blow the fuseAttached Files
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Re: 12" Macintosh Monochrome CRT monitor
The inrush limiter burn up can be due to short circuit, I would check the rectifiers, check the resistance between the +/- legs of the main filter cap at leastNever stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
Comment
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Re: 12" Macintosh Monochrome CRT monitor
Originally posted by budm View PostThe inrush limiter burn up can be due to short circuit, I would check the rectifiers, check the resistance between the +/- legs of the main filter cap at least
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