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Equipment Repairs => Satellite and Freeview forum => Topic started by: Turnip on November 30, 2011,06:55:38

Title: Thomson DT16300-16 PVR
Post by: Turnip on November 30, 2011,06:55:38

Hi folks,

Had a couple of these in where after changing the three usual PS caps, the PS won't fire up - tends to pulse but no shorts are evident even when power lead to main board is disconnected.

Any thoughts - Thanks - Chris.

Title: Re: Thomson DT16300-16 PVR
Post by: Bambooz on December 02, 2011,08:10:32

changed startup cap?
usually 47µF 35-50V near SMPS controller IC

if they dry up, the PSU can't start and acts like there's a short on the output somewhere.
I usually replace all the caps once i'm in there (except the 400+V primary filter grain silo). Especially if they're all the same crappy brand as the obviously failed/bulging ones.

[rant]
I'm almost willing to bet the originals are CapXons.. worst crap ever.
I've fixed countless computer and STB PSUs with those.. they're like a pest.
A 10V 1200µF CapXon on 5V-Standby doesn't survive much more than a year without puking its guts out.. should tell you a lot about the nonexistant quality
[/rant]

edit: brainfart.. have you also checked the other end (mainboard) for shorts?

Title: Re: Thomson DT16300-16 PVR
Post by: Turnip on December 02, 2011,12:34:43

Hi B/B,

I noted that PS wouldn't fire up with supply plug disconnnected, changed the cap you suggested, as you do with caps in the hot bits area.

Confess - need the cash from obvious repair jobs, so won't rant about crappy caps - bring 'em on - Chris

Title: Re: Thomson DT16300-16 PVR
Post by: Keith on December 08, 2011,05:18:49

Hi Chris,

I have had the rectifiers on the secondary fail with this type of PSU, but not always s/c, sometimes they fail only under load! Maybe show a little leakage when reverse biased.

Keith