Electrolytic capacitor replacement

[NH-GrizzlyBear]

Hi,

On one of Dave Jones videos, he talked about replacing capacitors; to use a higher uF value with a working voltage the same or higher if the value you're replacing is unavailable.  How much larger can it be?

I'm currently trying to fix a 'Panasonic DMR-E85H DVR' and one of the leaking caps was 56uF@35V.  The closest value in my stock was 100uF@35V.  Is this acceptable for the long term?

Also, I'm trying to locate a data sheet for a 'sub only coupler', part number B3PBA0000078 which drives a switching ic, part number C0DACZH00004 which gets its power supply filtered by the 56uF cap.

Any help is greatly appreciated!

[Simon]

Any idea what the capacitor is doing ? if It's a bypass capacitor bigger is fine although you could end up with a higher ESR that could cause problems. If it's say part of a filter you may want the right value.

[NH-GrizzlyBear]

Any idea what the capacitor is doing ? if It's a bypass capacitor bigger is fine although you could end up with a higher ESR that could cause problems. If it's say part of a filter you may want the right value.

D

Here is a portion of the schematic (a little blurry-sorry).  The cap high-lighted in orange is 56uF.

[Simon]

It's a bypass by the looks of it. Should be ok if your replacement is good quality

[NH-GrizzlyBear]

It's a bypass by the looks of it. Should be ok if your replacement is good quality

So, I can keep the 100uF?  Any ideas.how to get data sheets for the other parts in question, as VCC is mV and F/B voltage is also low, coming from Q1200 (only about 1V at the diode of the coupler).

[Simon]

Other than google voodo I can suggest much.

[marco99]

It's a bypass by the looks of it. Should be ok if your replacement is good quality

So, I can keep the 100uF?  Any ideas.how to get data sheets for the other parts in question, as VCC is mV and F/B voltage is also low, coming from Q1200 (only about 1V at the diode of the coupler).

Hi, I have the same DVD recorder and have to replace the 56uf  cap and 5 others that are leaking...how did you make out with the 100uf.

Thanks

[NH-GrizzlyBear]

It's a bypass by the looks of it. Should be ok if your replacement is good quality

So, I can keep the 100uF?  Any ideas.how to get data sheets for the other parts in question, as VCC is mV and F/B voltage is also low, coming from Q1200 (only about 1V at the diode of the coupler).

Hi, I have the same DVD recorder and have to replace the 56uf  cap and 5 others that are leaking...how did you make out with the 100uf.

Thanks

Turns out that the reason the 56uF blew was that both the 1.8V and the 3.3V regulators were failing under load! Changing the 100uF was moot.

[marco99]

Thanks for the info

[marco99]

I replaced the 56uF with a 47uF and 10uF in parallel (along with two 680uF and two 220uF)

It's working now......