[sdiy] Tama Techstar TS305 repair

[Oren Leavitt]

mark verbos wrote:
> Hi everybody,
> 
> I'm trying to repair a Tama TS305 for a friend and I'm stumped. It 
> powers up and works for about 3-5 min before the -15 rail drops down to 
> ground. I have narrowed it down to TOM1's card and replaced the 8 bypass 
> electrolytics, but no dice. I may replace the tantalums C5 and C6 just 
> because they are tantalums, but they're not even going to the -15 rail. 
> Is there some problem that these have that I should know about? Doesn't 
> it HAVE to be a cap if it's slowly dropping a few minutes after power up?
> 
> 
> thanks in advance,
> 
> mark

Hi Mark,

Have you measured total current draw on the -15V rail with and without TOM1?
Excessive current draw could be causing a -15V regulator (assuming power 
supply is regulated) to go into fold-back current limit or thermal shutdown.
One guess..

- Oren