broken oscilloscopes - Page 1
Forum section: electronics / testgear

author: Arlen moulton
author_rank: Regular Contributor
timestamp: November 13, 2014, 07:31:37 am
content: If I said to you that I was going to buy two broken Philips analogue osciloscopes for £10 what would you say?

author: godFather89
author_rank: Contributor
timestamp: November 13, 2014, 07:45:09 am
content: It depends but most likely they're hard and not worth to fix. If you can and reuse their good components, 10 pounds is a good price.

author: tautech
author_rank: Super Contributor
timestamp: November 13, 2014, 11:11:51 am
content: Quote from: Arlen moulton on November 13, 2014, 07:31:37 amWithout the sevice manual.Any apparent physical damage.To cover nearly all bases try for a 3rd for a few pounds more.Hope you have the knowledge of CRT HV and a MM capable of up to 3 KV and as is often needed to repair scopes.....another scope.

author: daqq
author_rank: Super Contributor
timestamp: November 13, 2014, 11:51:04 am
content: I'd ask about the types, and whether you want/need an oscilloscope and if you are really that interested in a scope. 10 GBP isn't that much, it'll at worst make for an interesting teardown. Also, occasionally, if you have two broken things with different faults you can combine them into one good one.

author: GEuser
author_rank: Frequent Contributor
timestamp: November 13, 2014, 01:21:58 pm
content: I would say , what's a Packet of Cigarettes worth , or a Rum and Cola and then decided after those extreme calculations ..

author: Monkeh
author_rank: Super Contributor
timestamp: November 13, 2014, 07:30:42 pm
content: Quote from: Arlen moulton on November 13, 2014, 07:31:37 amI'd say good luck.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 13, 2014, 11:46:27 pm
content: At that price, probably worth buying even if they're not economical to repair. You can at least get two vintage teardowns...

author: orin
author_rank: Frequent Contributor
timestamp: November 14, 2014, 12:17:53 am
content: Might learn something trying to repair them...At work, my boss got 3 dead Leader 'scopes locally for $20 each and we have spent a few bored moments fixing them. We had not quite the right manual to start with which made for some entertainment where the manual called for 100V on one power supply, but this version was only 80V... and the rail was down. It turned out all I had to do was ask - Leader emailed me the correct service manual within a day of asking about it!The fixes were mostly in the low voltage power supplies. Dead bridge rectifiers, a dead 7912 and a couple of dead transistors, a previous bad repair of a trace (probably broken replacing one of the voltage regs/power transistors). Finally, one had a dead transistor in the vertical final amplifier. All parts could be sourced locally as NTE equivalents, some even at Radio Shack! All that's left is to properly clean the range switches and we'll have a couple of good 50MHz 'scopes. The third doesn't have a case and is definitely a spares unit. Economical repair? Not if we charged for our time, but that wasn't the point.

author: nctnico
author_rank: Super Contributor
timestamp: November 14, 2014, 12:28:33 am
content: Repairing stuff is very helpful to sharpen fault finding and measuring skills which will help a lot while developing your own circuits.

author: Macbeth
author_rank: Super Contributor
timestamp: November 14, 2014, 01:21:53 am
content: Quote from: tautech on November 13, 2014, 11:11:51 amHaha. My first ever scope was a Telequipment D61, it would not trigger. I managed to wangle a service manual from the tech guy at my local college. All the ECC83 valves etc were fine. I actually used the scope to investigate itself and found a shorted germanium diode which I replaced with an 1N4143. Worked a treat after that!

author: tautech
author_rank: Super Contributor
timestamp: November 14, 2014, 01:50:10 am
content: Quote from: Macbeth on November 14, 2014, 01:21:53 amI had a D83 for a good while, large beautifully sharp display that I miss even today.But DSO's for me now.....

author: Ether
author_rank: Contributor
timestamp: November 14, 2014, 02:38:50 am
content: How coincidental, I was just deciding whether I should drop cash on 2 Hitachi V-212 scopes in "unknown condition". Apparently, the seller picked them up from an old warehouse and has zero idea whether they are working. I'm itching to throw the dice.

author: Macbeth
author_rank: Super Contributor
timestamp: November 14, 2014, 03:23:52 am
content: Quote from: Ether on November 14, 2014, 02:38:50 amIf they are dirt cheap - and you can find a service manual - then they are definitely worth it. Even if you never use them in anger, fixing stuff is always rewarding.That is one thing I utterly hate about the modern Chinese test equipment - Try and find an honest service manual? I mean they resort to idiocy like scraping off part numbers on the chips.It's only because of utter heroes that can reverse engineer Rigol, Hantek, et al. that their products are so popular in the amateur market. Come on you Chinese bastards, you are relying on free software from decades of open source Linux to develop your kit, but don't give back? It really is scummy, even if not technically illegal in China, perhaps.

author: Ether
author_rank: Contributor
timestamp: November 14, 2014, 04:05:14 am
content: Depends on whether you call 40 USD a piece worth it. But that argument is pretty much invalid for me because I personally like Hitachi oscilloscopes as compared to other brands, especially their layout. I'll probably pick up a couple to cure my boredom.Quote from: Macbeth on November 14, 2014, 03:23:52 amYeah, I agree with that. I haven't tried fixing Chinese oscilloscopes before but my friend who does it to turn a profit has more than a few nightmare stories. Most of the issues are normally frustrating to diagnose and it pays to know Chinese because the Chinese radio forums can actually be quite helpful.

author: poorchava
author_rank: Super Contributor
timestamp: November 14, 2014, 06:58:43 am
content: At that ptice I'd buy them even if only for parts or as a decoration. Such scope contains shitload of buttons, knobs, pots and the like, which normally may cost few bucks a piece.

author: GEuser
author_rank: Frequent Contributor
timestamp: November 14, 2014, 07:27:23 am
content: Quote from: Ether on November 14, 2014, 04:05:14 amDon't they haveLargerletters in computers over there

author: KJDS
author_rank: Super Contributor
timestamp: November 14, 2014, 08:08:15 am
content: Quote from: GEuser on November 14, 2014, 07:27:23 amThey do, but it's cheaper to send the smaller ones from overseas