Also you should replace the one LV power supply cap, 2200uF at 50VDC.
This one will "never" go bad.
Blocked
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If this 5000A had the F1040 driver boards in it, they MUST be replaced with the F6013 boards.
This is an important Sansui Service Bulletin, and a proper way to go about repairing those early 5000A units, and any 5000 models made afterwords afterwards using the defective boards.
It is not an option, it's mandatory, for safety reasons and possible fire hazard.
The new boards are available through online sources if you check.
Playing around with trying to repair the original F1040 boards is foolish to bother with.
I've done enough of them in the shop to know.
This is an important Sansui Service Bulletin, and a proper way to go about repairing those early 5000A units, and any 5000 models made afterwords afterwards using the defective boards.
It is not an option, it's mandatory, for safety reasons and possible fire hazard.
The new boards are available through online sources if you check.
Playing around with trying to repair the original F1040 boards is foolish to bother with.
I've done enough of them in the shop to know.
Order placed All 5 as you linked. should be here on Monday. Thank you for awesome help. Your guidance greatly appreciated. Once repaired i`m gonna keep it for a long time, I like how it looks and happy with functionality.
Mine has 6013 boards in it, thank you for reminder. Do you know what is the difference between them?
Those diodes are just fine. I already knew that, since with bad diode(s) there would have been
much worse symptoms than what you described.
Do you have some of this? You'll probably need it on the pots and switches.
DeoxIT(R), #D5S-6 - CAIG
While you're waiting look it over real well, and measure the four emitter reistors too.
Each should be 0.3 ohms, but if your meter is not accurate, at least make sure they all
seem to be about the same value. Subtract the meter lead resistance from the reading.
If those resistors are ok, I'd just replace the five capacitors and then use it for a while.
Then if you like it and want to put in the effort, replace all the other electrolytics in the unit.
There are a fair number of small ones, so it would be a significant amount of work, but it
shouldn't cost too much more.
Each should be 0.3 ohms, but if your meter is not accurate, at least make sure they all
seem to be about the same value. Subtract the meter lead resistance from the reading.
If those resistors are ok, I'd just replace the five capacitors and then use it for a while.
Then if you like it and want to put in the effort, replace all the other electrolytics in the unit.
There are a fair number of small ones, so it would be a significant amount of work, but it
shouldn't cost too much more.
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My meter shows 0.3 ohm on all 4 resistors.
My meter kinda slow measuring sub ohm resistance and only to tens of an ohm. Should probably get myself a better one.
Sounds like you are on the right path.. Actually capacitors that sit unused for decades will deteriorate more quickly in many cases than ones that are used on a periodic basis at moderate temperatures. (Heat is the enemy of component life.)
In a case like this a failure might result in the destruction of a part you may not be able to replace. I normally replace and then troubleshoot after. In many cases all of the odd problems just disappear with cap replacement provided that the unit in question was not put away broken.
Share some pictures as you go! 😀
In a case like this a failure might result in the destruction of a part you may not be able to replace. I normally replace and then troubleshoot after. In many cases all of the odd problems just disappear with cap replacement provided that the unit in question was not put away broken.
Share some pictures as you go! 😀
I see. I have limited experience replacing old components as you might noticed. I’ve had 80 years old radio with perfectly fine capacitors. It was stored for at least 50 years. Popped new tubes in there and it worked like a charm. Another interesting thing happened in my beloved GFA-5800 when rectifier bridge died. Upon replacement fired right up without replacing those soda can sized capacitors. Worked a decade after that before recapped strait up.
Them McIntosh protection circuits with small nichicons going bad in relatively short period if time.
I’ll post pictures in every step repairing this sansui. I have a warm feeling about it future thanks to unspeakable kindness of this board members.
Them McIntosh protection circuits with small nichicons going bad in relatively short period if time.
I’ll post pictures in every step repairing this sansui. I have a warm feeling about it future thanks to unspeakable kindness of this board members.
It's just common sense to use a Variac to slowly bring up the line voltage on old equipment
that has not been in recent use, at least if there are no visible problems to correct first.
But since you had already run it, then we go on to replacing the obvious components.
Since the emitter resistors all measure the same, let's assume they are ok for now. They probably are.
that has not been in recent use, at least if there are no visible problems to correct first.
But since you had already run it, then we go on to replacing the obvious components.
Since the emitter resistors all measure the same, let's assume they are ok for now. They probably are.
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It's been a few years since the last 5000 was on my bench....
Offhand, without the schematics in front of me, I can't give you an answer.
Looks good. When you first turn it on, please use safety glasses and stand away from the unit.
Have DVM(s) already attached to the new capacitors, to check the voltage.
By the way, it is important to not over tighten the mounting clamps.
They could pierce through the capacitor's wrapper and violate the voltage isolation.
Have DVM(s) already attached to the new capacitors, to check the voltage.
By the way, it is important to not over tighten the mounting clamps.
They could pierce through the capacitor's wrapper and violate the voltage isolation.