Capacitor replacement in old ECU's

**petergoudie** · 08-08-2009, 09:50 AM

Dear Witzl. I'm glad that I have access to a Jaycar employee. I want to preface this that I am a fan of Jaycar and purchase most of my parts from there. However, I've found that over the last few years when I send an email to Jaycar about an issue or indeed, there was one item I purchased where the instructions said to contact Jaycar for a full data sheet, I never receive a reply to any of the messages. I am coming to the belief that Jaycar policy must be not be to answer emails even though it appears they encourage emails to be sent. Am I correct?.

**TERRA Operative** · 08-08-2009, 10:28 AM

Well I guess if you want good capacitors, you have to pay for them...

**Sciflyer** · 08-08-2009, 10:44 AM

Originally Posted by The Witzl

yeah in tantalum the range probably wont cover an entire ECU, as our range only goes up to 47uF, so the big 220uF and 100uF caps arent covered.... but in electro the range should be sufficient.

Worst case scenario is piggybacking a few caps to get the right value

Nope im talking about electros, i dont touch the tantalums. Piggybacking electros in an environment like a car ECU (hot, vibration, crowded PCB) is not a good idea imo, id rather get the correct cap straight off.

Plus they are dual layer boards which makes it a PITA as it is!

**TERRA Operative** · 08-08-2009, 06:33 PM

Hot melt glue solves the vibration issue.

**ara_ara_ara** · 09-08-2009, 11:22 PM

Originally Posted by Sciflyer

Sometimes you dont have a choice as some of the caps are in less common values/voltages/package sizes/temp ratings

Ive had to order from RS for ECUs and PC motherboards before as Jaycar/DS/Altronics etc dont have the correct caps, i know for a fact you cant get all the ones to do a Z30 ECU

there is a place in woodville which sells the full range of the caps for UZZ30 ECU.
i got my set from there.
if you need them still them then let me know and i'll find where i got them from.

**JetspeedCamry** · 10-08-2009, 08:20 AM

So how would you know if your ECU was having problems with leaking caps? Apart from the obvious not being able to diagnose a problem after everything else is changed, or replicating symptoms on another car with the same ECU swapped in...what other tell tale signs are there?

**takai** · 10-08-2009, 08:24 AM

The fact that when you pull the ECU apart you can see the caps leaking...

**YLD-16L** · 10-08-2009, 09:40 AM

Originally Posted by JetspeedCamry

So how would you know if your ECU was having problems with leaking caps? Apart from the obvious not being able to diagnose a problem after everything else is changed, or replicating symptoms on another car with the same ECU swapped in...what other tell tale signs are there?

As noted some will/may be visibly leaking.

The last ECU I had to replace the capacitors in had an issue where there was residual current in the ECU after the ignition being turned off which kept it partially powered up due to the ECU's internal relay remaining energised. It was a capacitor issue and once replaced it's been fine.

**TERRA Operative** · 10-08-2009, 05:45 PM

IMO, it's probably a good idea to replace the caps in an ECU of this age as a matter of course.

That way, you're not chasing your tail later to find the problem.