Componenets to Replace to Eliminate LZ Whine

[NotFitForPurpose]

Hi,
I see the post has been around a while, though in checking it before I dived in on my noisy XP model, I noticed a small wrinkle.

I think the XP PSU board I have a Whine / noise issue with is the same one and, I suspect one of the graphic markup 10 uF capacitor orientations is a little off.
You can see the orientation on the original does not match the Pads underneath it, though the shrink covers can be a little off and tricky to identify (Nice partial transparency was used on the original allowing confirmation)!

What matters here is which pad is used for the negative terminal.
Here's my proposal (see the 10uF part in the centre of the cluster):

Modified-ByteMyVdu-Psion-LZ Capacitors.png

Here's my XP Rev 5.1 board PSU for comparison with the original and the capacitors still in place.

20250412-XP-PSU Rev 5.1.jpg

I note, in my case at least, the noise is principally from the Piezo element. Modulated somewhat when the load changes e.g. the On/Clear key pressed. On removal of the Piezo element, as a result of back cover removal in this instance, there is a very low level whine from the inductor.

Anyway removing components and replacing them presents no concerns to me. When I get the replacement parts I will measure the ESR of the removed components and pop it in this thread.

If the magic smoke escapes, I will let you know if I manage catch it and get it back in.

[1333david]

All of my 4 line Organisers whine and none of the 2 line machines (touch wood). I'd love to get the caps replaced, but I'm in the same camp as Martin and wouldn't be confident to do the fix myself and risk writing off my Organiser!

[NotFitForPurpose]

Hi,
when you say all.... out of curiosity how many is all?

I wondered if the failure mode might be associated with the "Great Capacitor Plague", though couldn't find the manufacturer listed with the usual suspects.

So leaning to end of life, rather than dodgy electrolyte. I am minded to pop the cans open and see what can be seen, though I have no microscope. I am expecting it to have 'dried out', as I can't see any obvious residue on the PCB.

Like a lot of things, it's not especially difficult when you have developed a technique, otherwise you are likely to have problems. 40+ years of desoldering components (and now I write it - it does feel too long), perhaps if nothing else offers the opportunity for reflection.

P.S. I blew up my first electrolytic (and last) when I was 14. In those days they often had no pressure relief feature, I still don't like bangs. That's the day I learnt they were polarised!

[1333david]

"when you say all.... out of curiosity how many is all?"

Good question. The whine is on two LZ64s (one is really bad). I thought my LZ also whined but I've checked again today and it doesn't. So not as bad as I first reported but frustrating and makes me reluctant to get another LZ64 in case I get another whiner (there are enough whiners in my household already ). No whine from my four 2 line models. Your theory linking the great capacitor plague is interesting. I wonder if later models are affected more?

PS. Just seen an LZ listed on eBay with "It has an annoying squeal whilst on." Good of them to mention it in the description.

[thesourcerer]

If anyone is up for it I have a dozen or so LZ/LZ64s with a capacitor whine that needs fixing.
Incidentally I might mention I’ve only got about 5&1/2 teeth left after pulling the train!
I can accept that there might be a failure rate, so if anyone is looking for a few hours work you can give me a guesstimate.
I don’t think it worth doing on XPs at this point in time. I’ve got enough decent ones that I was selling a while ago for £10 or £15 pounds!
Another thing I would be interested in is EXE keys if anyone can make some decent copies?

[NotFitForPurpose]

Pulling the train - "Pray tell us about the train."?

To more mundane things, I fitted the new barge board, corrected and refitted the gutter, applied black silicone sealant, tidied the garage and mowed the lawn.

Fed-up after all that and as the cat moved from my 'work bench', I decided to investigate capacitors..
ESR 14.3 Ohms (@ 1KHz) for the supposedly 100 uF capacitor. At 20uF ish, there are some uF's and electrons all over some ones floor, somewhere. In my case at least they came out with very little fuss as expected. As this was as much of an exploration as anything else, it was easier to pop the lot out - than not. I won't re-fit the 'good' parts, more out of habit than concern - based on my measurements at least.

The replacement parts arrive this week, so we will so how the fix goes.
Some eye candy for those into PCB's
"It's all his fault over there, that one on his own!"

20250413_180544.jpg

Marked up part state

NFfP-Modified-ByteMyVdu-Psion-XP Capacitors.png

[NotFitForPurpose]

Hi,
pleased to say - Silenced, with only beautiful key clicks from the Piezo tweeter and Beeps when it's supposed to.

So I imagine this kind of fault likely to arise on CM, XP's as well as LZ model's.

Somewhat un-interesting eye candy- repaired and re-fitted PCB

20250414_192048 Post Repair.jpg

[NotFitForPurpose]

Hi,
well an interesting thing happened today... As it’s the holiday weekend, I decided to look further into the power supplies state. As there was no immediate issue I could discern, such as badly manufactured capacitors (see prior post).

So I started by plugging in my shiny new Battery Saver so I could use my USB power supply and automatically attached my USB power measurement device, out of habit really. My intention was to get my scope out and probe the PSU busses and switching waveforms etc.

Turns out, it was sucking ~20 mA more than it should, even when it was in sleep mode!

Here's why:

FLIR_20250418_044259_264.jpg

You just know nothing that's supposed to be only sucking uA should not be doing that!

Here are the offending beasties!

20250418_190705.jpg

It's now not only silent, but also sucking mere uA to spec.

I'm still musing as to the failure mode and true root cause.

So what I had hoped to show would mainly for others be just a capacitor change held in easy to access robust through hole locations, turns out to be quite a bit more involved. At least in my case.

Hope you enjoyed the update?
Never believe anything you read on the internet

P.S. Thanks Martin for the circuit diagram

[thesourcerer]

All I can say to that at the moment is Hmmm?

[amenjet]

So those components failed and you have replaced them? Was the coil broken somehow?
Any idea why these failed?

Sorry, lots of questions...