I have a FSP350-60BT with one bad cap. It is a Fuhjyyu 1000uf 16v d8mm. I replaced it with a 1000uf 16v d10mm Rubycon YK, but the PSU won't startup. I test it with a PowerMax PSU tester and get nothing. I put the old Fuhjyyu back in and it starts. I then replaced the Fuhjyyu with a ChemiCon 1000uf 16v d10mm KZE and again it doesn't startup. Does anyone know of a replacement cap that will work for this PSU?
-
-
Re: Replacement for Fuhjyyu cap
Interesting - this is most probably a cap on the secondary side of the auxiliary flyback converter that generates +5Vsb. If it has a TOPSwitch power switch on the primary side, it may not reliably start with a larger capacitor on the secondary - a longer startup charge time triggers its internal overload protection, and it shuts down and tries to restart after a few tens of milliseconds, and keeps cycling thereafter.
This is the first instance I've heard of where an identically spec'ed replacement cap has caused problems - there is probably one other cap in the auxiliary flyback circuit which is marginal, maybe on the primary side. You may want to try with a lower-valued replacement cap - say 820/16, 680/16 or 680/25. -
Re: Replacement for Fuhjyyu cap
That´s for me the first issue too, i recaped a lot of 5v SB Topswitcher circuits with 1000uF to 1500uF without any issue.
But usually you should avoid caps larger than 1000uF may be you need less.
Have you replaced both caps in the o/p filter?
Try a GPO cap, if it is working with it, either lower the capacitance or try to use a older Low esr series with higher ESR.Comment
-
Re: Replacement for Fuhjyyu cap
2mm difference in cap size can cause such a big delay to cause PSU not to work *spooky*
Rubycon Rubycon RubyconComment
-
Re: Replacement for Fuhjyyu cap
Thank you each for your reply to my question. I have just tried using a Chemicon 16v 680uf KZE cap as a replacement but PSU still does not start. I will be followup on the other suggestions and let you know what results I get.Comment
-
Re: Replacement for Fuhjyyu cap
Probably there are other quirks like other bad Fuhjyyu caps? if yes may be you have to start from the begining.
Any way, you shopuld try to find the SMPS controler, usually a IC with 8 to 16 pins. there must be a smaller capacitor, wich is supplying the Vdd to the IC.
usually it is abouth 10uF to 50uF /25v to 50v.
Replace it withany cap near those values but 50v (GPO cap is ok, you don?t need Low esr there).
May be this solves your issue. If this cap is degrading, the IC won`t switch on, your PSu obviousely too.Comment
-
Re: Replacement for Fuhjyyu cap
my educated guess is the +12 rectifier is very leaky.
the ac popped the cap and now the new cap is a good short to the ac from the bad rectifier.
btw i have replaced that cap with a 3300@16 fm.
hey its all i had when i recapped that psu.
i am using that psu in this box now.
its been 6 months and no problems.
this psu has the cleanest +12 in town!Comment
Comment