Rhodes 100 watt suitcase cap sugesstions

[nosaj]

Got this Rhodes 100 watt suitcase
The regulator board is blowing fuses and burned traces on diodes cr1 and cr3 These are glass scintered diodes 3amp 100v Looks like a 1n5401 would be fine here.
I'm going to recapp it also The caps are all original White Mallory caps. The 500uf c3 and c4 what would be a suitable replacement would 470uf or 680uf be workable here? Got 470uf on hand.




Also the 11000uf caps are about the size of a soup can. Would these be fine here? https://www.mouser.com/ProductDetail...iPaiBdkYVdw%3d

nosaj

[Enzo]

470 and 500 are within each others tolerance. COnsider them the same.

[J M Fahey]

Yes, they are the same.
Only "old style" scales for capacitors often went "2-5-1" so it was common to see, say, .02uF , .05uF , .1uF and so on, since precision was 20% or worse.

Now manufacturing is more precise so they can follow a scale similar to resistors, thus the exact same 50uF cap is called 47uF today, 25uF became 22uf and so on.
And even if you upgraded to 680uF or even 1000uF (which would probably fit), no big deal.

[nosaj]

So for future things. If a schematic says +-20% for example a 1000uf cap I could go up or down 200uf since 1000*20%=200 Is this correct as far as figuring things?

Thanks,
nosaj

[Justin Thomas]

Generallyschematic tolerances are for voltages, at a prescribed set of test conditions. The parts tolerances are unique to the parts. If a resistor is marked at a 5% tolerance, it is out of spec, even if the schematic says tolerances are +/-20%.

Justin

[nosaj]

Generallyschematic tolerances are for voltages, at a prescribed set of test conditions. The parts tolerances are unique to the parts. If a resistor is marked at a 5% tolerance, it is out of spec, even if the schematic says tolerances are +/-20%.

Justin

And Electrolytics are what tolerance these days?

also have a trace that has lifted , it is similar to like the old Peavey traces. I used a fiberglass pen to scrub under the traces to get rid of any charring. Can i use super glue to reattach it to the pcb(seems to be a fiberglass pcb) or should I just snip it and run a wire between the points? It'd from CR1 to pin6 on the regulator board.

Thanks,
nosaj

[Justin Thomas]

I don't know what tolerance lutics are these days. My point was, that depends on the individual parts... If a schematic or BOM specs all caps are +/- whatever, it could be reasonably assumed all the caps are within that spec, but may be tighter, in which case again, a cap 4% out of spec for a 2% toleramce would still be out of spec. Doesn't mean the device will malfunction, though...

Justin

[J M Fahey]

If pad is covered in shiny bright clean solder, so you do not have to heat it as much as possible and wait (even if a few seconds) for rosin/flux to clean surface, but just melt solder (pre-tin the component you will add) , I bet Krazy Glue will stand the couple seconds solder is actually *molten*.
I use epoxy which definitely stands the temperature, simply because I make and recone speakers and always have it available within reach but for a quick fix, KG should work.

[nosaj]

Ok everything is fixed up. Looked through the many bins and found NTE5801 http://www.farnell.com/datasheets/1483202.pdf
Which I think meets what this parts list asks for for CR1 100v 3a.
http://www.fenderrhodes.com/org/ch11/fig11-5.html

nosaj

[nosaj]

Ok been burning it in sounds pretty good playing Pink Floyd through the cabinet.

nosaj
Thanks for the help guys