Leader Lbo-5825 Oscilloscope - Page 1
Forum section: electronics / repair

author: Alf Torp
author_rank: Newbie
timestamp: May 05, 2019, 12:55:54 pm
content: Hi,new to the forum, dabbling in electronics and repairing all sorts of stuff. Mechanics, electronics and more.I've scored a Leader LBO-5825 but I get no life in the crt. No trace or other signs of activity. I've been looking for any documentation on the LBO-5825 that I could find, but so far; zilch. Nada. Not so much as a comma.Can anyone here help out getting for instance the service manual, owners manual, schematics or anything like that? I'd like to get the bugger working again.Cheers,Alf TorpNorway

author: Chris56000
author_rank: Frequent Contributor
timestamp: May 05, 2019, 08:08:01 pm
content: Hi!Have you tried (carefully) seeing if the Leader badge is removeable? I'm fairly sure the LBO–5825 is a badged version of something you will find a manual for – it looks very much like something of Iwatsu manufacture to me, and Iwatsu do have schematics and service info in many of their manuals!Failing that, open up your scope and see if you can get me one or two of the PCB reference numbers!Chris Williams

author: pbarton
author_rank: Frequent Contributor
timestamp: May 05, 2019, 09:44:48 pm
content: Looks like the Leader LBO–5825 has two or three more buttons than a Leader LBO-516.The Leader LBO-516 Oscilloscope Operating & Service Manuals are available on CD from Artekmediahttps://www.ebay.com/itm/391537865516andhttp://artekmanuals.com/

author: Alf Torp
author_rank: Newbie
timestamp: May 06, 2019, 06:13:59 pm
content: Quote from: pbarton on May 05, 2019, 09:44:48 pmThanks, I'll check it out!

author: Alf Torp
author_rank: Newbie
timestamp: May 06, 2019, 06:15:37 pm
content: Quote from: Chris56000 on May 05, 2019, 08:08:01 pmThanks, Chris!I've opened it up and there are a lot of Leader branded components in there, so I don't know...The "main board" is T-33338-P1, then there is a board T-33288-P1. I've found the power board, with the rectifiers and some test points marked with what I assume to be the supposed voltage.Thus, I've found that the 12V, -12V (TP3 and TP4) is missing. Other test points are also showing erratic readings so I am thinking there is some busted voltage regulator business going on, though I'm having trouble pinpointing them.

author: Alf Torp
author_rank: Newbie
timestamp: May 07, 2019, 06:10:12 pm
content: Anyone know what the D859 is? I've not been able to find anything useful, my google fu is letting me down... This is from the power board.

author: pbarton
author_rank: Frequent Contributor
timestamp: May 07, 2019, 10:20:41 pm
content: If you go tohttps://www.manualslib.com/download/1232936/Leader-Lbo-524.htmland click where it says "Download PDF" you will receive a .pdf of the Leader LBO-516 service manual.There is a lot of commonality between your Leader LBO–5825 and the Leader LBO-516.On .pdf page 30 of 34 there is the power supply.Q1 = 2SD859

author: Alf Torp
author_rank: Newbie
timestamp: May 08, 2019, 04:31:27 am
content: Quote from: pbarton on May 07, 2019, 10:20:41 pmGot it. (your advice)Found it. (the 2SD859)Ordered it. (same)...and a couple of other likely suspects.I downloaded another service manual for the 516 yesterday, but interestingly, the schematics looked rather different. This one looks very similar indeed, so thanks again