English Amiga Board - View Single Post - Dead A1200 (+5V only 287Ohms against ground)

bebek · 04 June 2017, 22:50

Those resistors ar low value below 5 ohm and you will measure them as a short - it is correct. They are connected through caps to ground and as you said resistance there is correct. You are in wrong place. Turn it on and feel all IC's with finger. One of them may be hot. Same applies to all ceramic capacitors - be careful as you may be burnt. There is also resistor 4.7 ohm that provides power to modulator. This one may go hot too if modulator is faulty. Already had two fails like this.

R301 is 10ohm and most of meters will beep (some even up to 50-60 ohm) - it is correct.

04 June 2017, 22:50	#7
bebek Registered User Join Date: Dec 2009 Location: Poole UK Posts: 349	Those resistors ar low value below 5 ohm and you will measure them as a short - it is correct. They are connected through caps to ground and as you said resistance there is correct. You are in wrong place. Turn it on and feel all IC's with finger. One of them may be hot. Same applies to all ceramic capacitors - be careful as you may be burnt. There is also resistor 4.7 ohm that provides power to modulator. This one may go hot too if modulator is faulty. Already had two fails like this. R301 is 10ohm and most of meters will beep (some even up to 50-60 ohm) - it is correct.