Electrolytic Capacitor Exploding

[Rein Wiehler]

I have a problem with a bunch of Diskless workstation, they are
exploding a filter cap near the CPU. The origional Part is a 1000uf
6.3v. I replaced them with 1000uf 16v. This new capacitor lasted
almost a year. I assume the ESR at the switching frequency is
generating too much heat.

Does anyone have a recomendation for replacing this failing Capacitor?

I am space limited. The origional cap is about 300 mil dia. by 600
mil height.

Should I increase the capacitance?

Should I increase the voltage rating?

Should I parallel multiple capacitors of reduced value? (spreading
the heat load?)

Should I attempt to find a custom capacitor with a lower ESR value?

Chuck Todd

does this happen to be a "ABIT" board. There was problem with low ESR
caps on those boards
rw

 

[Boris Mohar]

I have a problem with a bunch of Diskless workstation, they are exploding a
filter cap near the CPU. The origional Part is a 1000uf 6.3v. I replaced
them with 1000uf 16v. This new capacitor lasted almost a year. I assume the
ESR at the switching frequency is generating too much heat.

Does anyone have a recomendation for replacing this failing Capacitor?

I am space limited. The origional cap is about 300 mil dia. by 600 mil
height.

Should I increase the capacitance?

Should I increase the voltage rating?

Should I parallel multiple capacitors of reduced value? (spreading the heat
load?)

Should I attempt to find a custom capacitor with a lower ESR value?

Chuck Todd

See: http://www.niccomp.com/taiwanlowesr.htm



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/
Aurora, Ontario

 

[Chuck Todd]

I have a problem with a bunch of Diskless workstation, they are exploding a
filter cap near the CPU. The origional Part is a 1000uf 6.3v. I replaced
them with 1000uf 16v. This new capacitor lasted almost a year. I assume the
ESR at the switching frequency is generating too much heat.

Does anyone have a recomendation for replacing this failing Capacitor?

I am space limited. The origional cap is about 300 mil dia. by 600 mil
height.

Should I increase the capacitance?

Should I increase the voltage rating?

Should I parallel multiple capacitors of reduced value? (spreading the heat
load?)

Should I attempt to find a custom capacitor with a lower ESR value?

Chuck Todd

 

[Robbie Banks]

Try getting back to the motherboard manufacturer.

There was a piece in the IEEE spectrum last year about how they had fecked
up there electrolyte solution. Said that most manufacturers would replace
the part in question if it failed

 

[Dieter Wiedmann]

I have a problem with a bunch of Diskless workstation, they are exploding a
filter cap near the CPU. The origional Part is a 1000uf 6.3v. I replaced
them with 1000uf 16v. This new capacitor lasted almost a year. I assume the
ESR at the switching frequency is generating too much heat.

Try one of the OS-CON series capacitors made by Sanyo.

http://www.secc.co.jp/retri_e/os_rlt_index_e.html


Regards,
Dieter

 

[Chuck Todd]

Try getting back to the motherboard manufacturer.

There was a piece in the IEEE spectrum last year about how they had fecked
up there electrolyte solution. Said that most manufacturers would replace
the part in question if it failed

Already tried that, they say it is an enviromental issue!

Thanks,

Chuck Todd

 

[Chuck Todd]

does this happen to be a "ABIT" board. There was problem with low ESR
caps on those boards
rw

No, it is custom.

Chuck Todd

 

[Chuck Todd]

See: http://www.niccomp.com/taiwanlowesr.htm



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/
Aurora, Ontario

Thanks,
I knew about this problem, It is not the base problem in my case. My
problem is a design fault.

Chuck Todd

 

[John Robertson]

Digi-Key has a section of special low ESR hi-frequency capacitors,
find one that is rated as high a frequency as you can - the voltage is
probably OK @ 6.3V (size issues!) but if it is overheating then it
might not have been a hi-frequency cap.

A fan on that area might be a good idea as well...

Sometimes people forget that switching supplies are hi-frequency and
require special caps to reduce internal heating. Low ESR is only ONE
component of a hi-frequency cap AFAIK.

John :-#)#

I have a problem with a bunch of Diskless workstation, they are exploding a
filter cap near the CPU. The origional Part is a 1000uf 6.3v. I replaced
them with 1000uf 16v. This new capacitor lasted almost a year. I assume the
ESR at the switching frequency is generating too much heat.

Does anyone have a recomendation for replacing this failing Capacitor?

I am space limited. The origional cap is about 300 mil dia. by 600 mil
height.

Should I increase the capacitance?

Should I increase the voltage rating?

Should I parallel multiple capacitors of reduced value? (spreading the heat
load?)

Should I attempt to find a custom capacitor with a lower ESR value?

Chuck Todd

(Please post followups or tech enquires to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Chuck Todd]

Thanks for the Info.

I'll Check them out.

Chuck Todd

 

[Chuck Todd]

Thanks Dieter,

I will check Sanyo out.

Chuck Todd

 

[coolmos]

Thanks for the Info.

I'll Check them out.

Chuck Todd

Here are some possibilities:

United Chemi Con

KY6.3VB1000MH15 8x15mm Z=0.069 Ohm @ 100kHz/20C 6000hrs@105C
LXZ6.3VB1000MH15 8x15mm Z=0.09 Ohm @ 100kHz/20C 3000hrs@105C

Rubycon

JXA series
YXG series

Yageo

SC series
SM series

Good luck !