H89 Tantrum...

[Steven Hirsch]

<sigh...>

This is what happens when a 40 year old 20V tantalum cap sits on a nominal 18V
bus. I replaced all three of the input caps on the +- 18v rails. Would have
liked to do all of them, but I didn't have enough in the parts drawer.

[Glenn Roberts]

The only ones I’ve ever seen go are the ones on the 18v line. I think Heath only spec’d 25v tant’s there? Definitely need 35v. Those are the ones I’d focus on if your supply is limited…

Sent from my iPad

> On Dec 18, 2024, at 12:48 PM, Steven Hirsch <snhi...@gmail.com> wrote:
>
> <sigh...>

>
> This is what happens when a 40 year old 20V tantalum cap sits on a nominal 18V bus. I replaced all three of the input caps on the +- 18v rails. Would have liked to do all of them, but I didn't have enough in the parts drawer.
>

> --
> You received this message because you are subscribed to the Google Groups "SEBHC" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to sebhc+un...@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/sebhc/c837b222-c44d-5b41-6ba9-e34fce9c70a0%40gmail.com.
> <h89_tant.jpg>

[Steven Hirsch]

On 12/18/24 13:12, Glenn Roberts wrote:
> The only ones I’ve ever seen go are the ones on the 18v line. I think Heath
> only spec’d 25v tant’s there? Definitely need 35v. Those are the ones I’d
> focus on if your supply is limited…
>

They may have spec'd 25V, but my CPU board was fitted with 3.3/20V parts. I'm
surprised they lasted this long! I did end up replacing all (3) caps on the
18V buses. I must say it was colorful when it went - and I'm glad I wasn't
leaning over it at the time :-).