Thandar TS3022S Repair

[TaylorD93]

Hi all,

Recently got my hands on a THANDAR TS3022S 2 channel PSU.

Typical THANDAR Linear design, but with the LCD 7 Segments instead of the older PL series LED Segments.

The only issue i have with it, is that the 2nd PSU Channel has had the Switch removed for the DC output. It was done a few years ago and the hole had a large Calibration Void sticker just fitted over the hole. The tag which came with the equipment said no power on. I traced the no power fault to a broken Line conductor at the plug, but i want to get a new switch to use the 2nd channel. Does anyone know where i might be able to find a replacement switch? i have no part numbers etc to use for reference etc.

I cant find any service manuals for this model online, and so far ive had no luck finding the Panel mount, with PCB solder terminations switch to directly fit to the PSU. I dont really want a big hole around the switch if i use a PCB mount toggle switch etc.

I think its quite an early model, based on the date code of the Caps it may be 14th week 1990, and has a single large 4700uF 63V cap per PSU channel, i have seend BD139 had a post on here of a similar model but had smaller parallel bulk caps, so i know the design was changed over time, but i dont know if the switches are all the same etc.

I did email TTI but ive not heard anything back yet, so hope someone here might be able to help


Any help would be appreciated will try to upload some photos this weekend.

[m3vuv]

dont know if this will help? https://www.eevblog.com/forum/testgear/ts3022s-services-manual-here/

[Andy Watson]

The key to finding the manuals is to search for TTi (or Thurlby Thandar etc.) S-Series.

I would also like to find exact switch replacements. I believe the originals are obsolete. The nearest substitute that I've found is a C & K 7201 (with bezel) - it fits, but not very well

[TaylorD93]

dont know if this will help? https://www.eevblog.com/forum/testgear/ts3022s-services-manual-here/

I saw that thread, a few posts down there was a link to another site, i tried the S series download. but it doesnt seem to match my PSU, different cap values etc. But will keep looking.

edit: im an idiot 

I found the service manual, thanks M3vuv.

Looks like i need 22219-0080 or a 22219-0110 switch

[m3vuv]

cool,just a simple case of finding one then

[TaylorD93]

Well i eventually found a solution to this, I found a C&K Switch 611/621 series would pretty much fit.

I contacted them, however after a quick chat they informed me that the usual Paddle type of switch for these PSU's, i.e. 621 series, had a MOQ of 100, and i wasnt 100% sure that the pins would fit.

So i bought the most convenient switch from Farnell, C&K DM61J12S205Q, Order Code:2931730

This was pretty much a perfect panel mount fit, however a few differences;

1) This is a 611 series, "Rocker" type instead of the Paddle type.

2) The Terminals are solder lug, so i looped some 20AWG tinned copper wire through the solder lug, then into the PCB holes. with some heat shrink over just for extra caution.

3) It was very very close depth wise before hitting the terminal/switch PCB. So it marginally fitted on mine, however others may have difficulty.


But overall, in my case, it fits, it works and can take the full 2A just fine So thought id pass it on as a possible solution!

[TaylorD93]

Calibration is a little out, but will get me by for now