4900 chassis dead

paul400

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i aquired a 4900 monitor in addition to the pacman i just bought. no neck glow , getting the 120v to the chassis, swapped out a 4900 chassis and the tube picture looks great. looks like it has never been capped, order a cap kit, can a cap cause the whole chassis not to work? what would be some of the first steps to troubleshoot this chassis?
 
Agreed....

Do a full cap kit, check the chassis and neckboard over for bad solder joints, and see what happens then.
 
ok i recapped it last night and no go...checked R503 is measuring 167v and 174. should i check the hot and V.R. on there cases with monitor on right? what should be the correct voltages on these?
 
Check for cold solder points...the last 4900 I fixed that was dead had one on a larger resistor I think. I remember it was near the front edge of the chassis I believe (the side that normally faces the tube). You'll see some long traces that go from one side to the other.

I wanna say it was a ceramic resistor standing up on end but I may be thinking of a K7000. Its almost 3am here ;-)

EDIT: Now I remember...I think it *was* a ceramic resistor, and it wasn't a cold solder point, it was a lifted pad. You could BARELY tell at all...at first glace it looked perfect, but I think I bumped the chassis and noticed the solder point lift off the board. Used a heavy resistor leg to bridge it and all was well.
 
Last edited:
Check for cold solder points...the last 4900 I fixed that was dead had one on a larger resistor I think. I remember it was near the front edge of the chassis I believe (the side that normally faces the tube). You'll see some long traces that go from one side to the other.

I wanna say it was a ceramic resistor standing up on end but I may be thinking of a K7000. Its almost 3am here ;-)

EDIT: Now I remember...I think it *was* a ceramic resistor, and it wasn't a cold solder point, it was a lifted pad. You could BARELY tell at all...at first glace it looked perfect, but I think I bumped the chassis and noticed the solder point lift off the board. Used a heavy resistor leg to bridge it and all was well.

i wll go over the wohole board again and look at the joints,and that ceramic resistor
 
i was about to shelve this chasiss, but i gave it one more shot. replaced ic301 and r363 and picture!!! very happy had to show my wife.
 
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