Transistor socket corrosion in 4xx series Tektronix scopes - Page 1
Forum section: electronics / repair

author: rhb
author_rank: Super Contributor
timestamp: July 01, 2018, 10:43:32 pm
content: Does anyone have a good solution for rehabilitating a piece of gear that has been in storage in a humid climate for 15 years?Are there potions that will *safely* clean the sockets? I've got a Tek 465 and a Dumont 1060 I'd like to revive. Both are socketed semiconductors throughout. I plan on using a hot air system and liquid flux to rework all the solder joints, but removing the sockets and directly soldering the transistors is not a very attractive proposition.

author: Kosmic
author_rank: Super Contributor
timestamp: July 01, 2018, 11:42:47 pm
content: Deoxit d5 improve metal to metal contact and help remove corrosion. So I would probably try that first.But how much corrosion are you talking about ? Replacing the sockets might be a option too.

author: particleman
author_rank: Regular Contributor
timestamp: July 02, 2018, 12:39:05 am
content: Quote from: Kosmic on July 01, 2018, 11:42:47 pmWhat he said^^I remove the transistor wipe the leads with a q-tip soaked in deoxit and wipe the socket squeezing a little into the socket. Make sure you double check the leads are socketed when you replace them. I was working on a 465 a few weeks ago and bent one lead. No sweep when I turned it back on. Took me forever to find the transistor that I bent the lead on. I usually do the edge wipe ICs also.

author: rhb
author_rank: Super Contributor
timestamp: July 02, 2018, 02:25:07 am
content: Quote from: Kosmic on July 01, 2018, 11:42:47 pmI'd rather just sell the scopes than replace all those sockets. At that level of effort I'd get rid of the sockets and eliminate the problem completely.While it seemed like a good idea at the time, it was actually really stupid. The transistors are much more reliable than the sockets.

author: particleman
author_rank: Regular Contributor
timestamp: July 02, 2018, 03:04:05 am
content: Quote from: rhb on July 02, 2018, 02:25:07 amLet me know the price. I would love to have another 465 to work on.

author: rhb
author_rank: Super Contributor
timestamp: July 02, 2018, 09:29:41 pm
content: Quote from: particleman on July 02, 2018, 03:04:05 amThey are pretty awesome. Just reading the service manual makes you feel good. You can feel the passion of the team that produced that series of scopes. I'm probably going to buy a refurbished 485 that the seller tells me is super clean. It won't be cheap, but he repaints the hosuing and replaces failure prone caps, etc. He goes through a pretty detailed procedure. Digital scopes do some really nice things, but the great virtue of an analog scope is there are no bugs that only the OEM can fix.

author: particleman
author_rank: Regular Contributor
timestamp: July 02, 2018, 10:21:40 pm
content: Quote from: rhb on July 02, 2018, 09:29:41 pmI bet you will be getting one of my cases with your 485 I just sold him a few. 485 is a great scope I have 2 of them.

author: tggzzz
author_rank: Super Contributor
timestamp: July 02, 2018, 11:28:00 pm
content: Quote from: Kosmic on July 01, 2018, 11:42:47 pmI've removed the transistor, used a jeweller's screwdriver to put a tiny dtop of D5 on each socket, and reinserted the transistor. Has it helped? Don't know, but it hasn't harmed.Rather than replacing the sockets, I'd simply solder the transistor nito the socket -but I've never found that necessary.