Power Designs TW-4005 Service Manual/Schematic needed - Page 1
Forum section: electronics / testgear

author: GST_Greg
author_rank: Newbie
timestamp: June 13, 2019, 08:42:24 am
content: Anyone have a copy of the service manual and/or schematic for the Power Designs TW-4005?I'm usually pretty good about locating such things on the internet, but this one is looking tobe unobtanium at the moment...One side is having issues, and would like to repair it to working condition, as I do on all ofmy vintage equipment.Thanks in advance,Greg

author: GST_Greg
author_rank: Newbie
timestamp: June 19, 2019, 01:48:25 am
content: No one? Really??Ok, thanks.Greg

author: rsjsouza
author_rank: Super Contributor
timestamp: June 19, 2019, 03:16:44 am
content: I found the discussion below that gave me some hope to find it, but it seems the referenced manual is for the TW5005T instead.https://www.eevblog.com/forum/reviews/power-designs-tw-4005-teardown/For years I couldn't find a manual for my 5015A. I then found it on an eBay listing that was a short driving distance from my house. Unfortunately the company went bankrupt and probably their manuals are now ashes.

author: GST_Greg
author_rank: Newbie
timestamp: June 21, 2019, 09:03:50 am
content: Yep, I did find that post before posting my own thread.Hmmm... I guess i'll try to find a manual for one of the single supply versions andgo from there.Thanks for the reply!!Greg

author: PaulEE
author_rank: Newbie
timestamp: November 21, 2021, 07:43:51 pm
content: Do you still need the schematic for the 4005? I just bought "Model 4005,4005R" factory manual on eBay...happy to digitize and share if you so desire. I am pretty sure the TW4005 will be similar, if not identical. I have bought several of them; the 4005R is just the "wider than it is tall (R)" version of the "taller than it is wide (no R)" version.Lemme know...I know it's been awhile.PaulPianoman0488

author: rsjsouza
author_rank: Super Contributor
timestamp: November 21, 2021, 10:21:57 pm
content: Paul, if you are willing to do a good digitalization, perhaps consider placing it in K04BB, which is a great resource for test gear manuals.I personally have uploaded a number of manuals there and some of them were simply better copies of existing ones already roaming on the internet.I still have a few more to upload, including a decent schematics scan of the HP3314A.

author: PaulEE
author_rank: Newbie
timestamp: November 21, 2021, 11:38:03 pm
content: I may just do that. I do see the TW probably stands for "twin", but I believe the schematic would be almost identical, if they do indeed mean "twin = identical". It appears to be a popular supply, and I think it would be beneficial to digitize and post. Thanks for the suggestion, I do know the website you're talking about. I'll poke this post when I get to a machine that can do it (probably at work)...otherwise, it's me and a DLSR and GIMP hard-limiting it to black and white, which would probably work...Regards-Paul

author: rsjsouza
author_rank: Super Contributor
timestamp: November 21, 2021, 11:49:07 pm
content: Indeed good large format scanners are hard to come by. Especially ones that do not add heavy JPEG compression to the images.When I get my way with a good scanner, I scan in either colour or 256-greyscale at a minimum of 200DPI (600DPI for schematics, as minute details matter more) and using TIFF (If the scanner permits). The hardest are those HP large diagram/schematic pages, which usually need manual stitching. But my reason is that, if it is done once at a very high quality, a low quality/low bandwidth version can be created any day.

author: PaulEE
author_rank: Newbie
timestamp: September 27, 2023, 06:34:18 am
content: Sorry it took so long. I am going to attempt to attach my PDF here. I finished it tonight and began it late 2021. The way in which I corrected / cleared up the photographs varied, but it is all very legible; particular attention was paid to the schematic, of course. We all know how irritating it is to say "is that a 6 or an 8!?" whilst squinting at the screen. No squinting here. For the record, this took a few hours between 2021 and now, so if I see this on eBay it will be quite disheartening. I paid $20-$30 (can't remember) for the hard copy. The TW-4005 should essentially be a double of this circuit, but don't quote me, I don't own the TW-4005, just the regular 4005 and 4005R (rackmount? wider than tall version, see last pg).Enjoy, hope it helps someone.Edit: The max file size is 4MB and my HQ version of the PDF is ~8MB Posted here is the "portable" version, which is still legible but looks like crap to me comparing it to the HQ version. If you need the HQ version, private message me your email address and reference this thread. Thanks.