[Nottingham] need new wireless hub

Martin martin at ml1.co.uk
Tue Jun 7 09:19:10 UTC 2011


On 6 June 2011 23:26, James of the family Moore
<jmthelostpacket at googlemail.com> wrote:
[---]
> psu if you buy it from China, they tend to cook after a while.

Not sure for actual point of manufacture but I've just had two
capacitors explode on a 12v switch mode PSU from a long established
company in Taiwan. It's a type that isn't easily sourced that fits
into a shaped housing, so I thought I'd do a quick fix and replace the
capacitors...

Mmmm... Whereupon I discovered that only two out of a group of four
capacitors had been installed. The installed two likely blew due to
overheating due to their poor ESR. Higher spec replacements were
physically too big to fit... Some deft rearranging and resoldering
fixed that. Trying to reassemble the unit gave a rather strange
unnatural fit... And one of the heatsinks had been precision cut to
avoid non-existent components. Bulk multi-function part or?... A
flange on the heatsink had been formed the wrong way so that the
heatsink was upside-down! Getting that to fit had then forced another
heatsink to be awkwardly placed... I just wonder if the two capacitors
had been left out for cost-cutting or for bodged manufacturing
convenience! Anyhow, a bit of metalwork later and everything fitted
back together nicely, complete with some additional ventilation slots.
All now runs sweet and cool.

Adding up time, that one must now rate as one of the most expensive
switch-mode PSUs ever! Then again, trying to get a replacement would
have taken a few days in any case, even if I could order just the one.

All good fun, all for the sake of shaving a few pence off a component cost.

Cheers,
Martin



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