Personal LaserWriter NT PSU Capacitors

[zuctronic]

Hi all, I thought somebody might find this helpful as I've seen a few "dead personal laserwriter" posts here.

I have a couple Personal LaserWriter NT guys that are at different stages of dead. When I received them, neither one would power up. I found a new old stock replacement PSU on eBay that only achieved partial success. The printer would power up, I could see it via AppleTalk and query the specs, but it wouldn't print a test page. Finally, I bit the bullet and disassembled the PSU and removed all the electrolytic capacitors, replacing them with what I believe are acceptable replacements. After installing this re-capped PSU, I do get a test page but it's pretty awful. The toner is fully fused to the paper, but there are dark blotches all over the page and it's mostly illegible. There are absolutely more f'ed up caps in the beast, so I'll be going back in for more over the coming weeks.

I believe this printer shares the same PSU with other personal laserwriters.

To any brave souls wishing to follow in my footsteps, here is a list of the caps from the PSU:

PSU PN = RG1-2298

C5 = 200v 680uf
C10 = 63V 22uf
C14 = 35v 220uf
C15 = 25v 47uf
C18 = 25v 100uf
C19 = 35v 470uf
C21 = 35v 47uf
C22 = 25v 100uf
C25 = 10v 1000uf
C26 = 10v 1000uf
C30 = 10v 1000uf
C32 = 50v 1uf

... and a digikey cart link to order the same ones I used:

https://www.digikey.com/short/rnzc3qzw

I hope this helps somebody!

 

[danda]

Wow, thanks for the comprehensive list of caps - I may try and repair some of mine (although then I'd feel even worse about throwing it out after...).

The toner is fully fused to the paper, but there are dark blotches all over the page and it's mostly illegible.

Likely to be the toner cartridge, and the infamous wiper blade it contains. The HP 92275A (or 75A as it's also known) didn't go out of production that long ago, so you can probably find one that's still decent.

 

[zuctronic]

Wow, thanks for the comprehensive list of caps - I may try and repair some of mine (although then I'd feel even worse about throwing it out after...).


Likely to be the toner cartridge, and the infamous wiper blade it contains. The HP 92275A (or 75A as it's also known) didn't go out of production that long ago, so you can probably find one that's still decent.

After replacing every other capacitor in the printer with no discernible improvement in print quality, I think you may be right. I haven't found a source for replacement wiper blades for that particular cartridge... and I've tried a few "new old stock" replacement cartridges that exhibit either similar quality or worse.

If the cartridges can't be refurbished, I'm afraid it won't be easy to get this working like new.
I've also got a LaserWriter 16/600 PS that does nearly the same thing and it's got a 98A cartridge in it with likely the same wiper blade problem. I've found a source for new wiper blades here:

Wiper Blade EXWB20 (10 pack)

Buy compatible wiper blades to remanufacture HP 92298A, 92298X, Canon EP-E toner cartridges (Printers:HP 4, 4+, 4M, 4M+, 5, 5M, 5N, 5se, Brother HL-960, 1260, 1660, Apple Laserwriter Pro 600, Pro 630, 16/600PS, Canon LPB-8N, 860, 1260, 1260+, EX)

quickfillonline.com

But first I'm going to try a 2007-manufactured cartridge that is on the way here now.

As far as this thread / post are concerned, the PSU capacitor replacement did repair the PSU, and resolved the problem of the printer not powering on, fuser fault, not fusing toner fully to the paper, and possibly other intermittent issues.

 

[3lectr1cPPC]

Great list - I'll add the values to my cap reference library on my website.