ST Nortel PNE-5 PSU Service & Recap

Repairs & upgrades.
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Steve
Posts: 2570
Joined: Fri Sep 15, 2017 11:49 am

ST Nortel PNE-5 PSU Service & Recap

Post by Steve »

Acquired a filthy 520 ST recently and just going through the process of servicing it. Here is the PSU.

Also, link to Icky's post about his PSU.

Chip is NE5561N
Caps are 2x 470uF 25V and 3x 4700uF 16V


Start to finish:

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Put some capton tape over the wires as I didn't like the idea of them being naked like that...

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Decided to ESR test a couple of the old caps to see how they were doing:

4700uf 16v:
5612uf
Vloss = 1.6%
ESR = 0.17 Ohms


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470uf 16v:
544.7uf
Vloss = 0.8%
ESR = 0.22 Ohms


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rubber_jonnie
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Re: ST Nortel PNE-5 PSU Service & Recap

Post by rubber_jonnie »

That is a nasty looking PSU, not keen on that potting or the bare wires. It's power without the price for sure........

I had to build one for my own 520ST, thanks for internals Meanwell :)
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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