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Possible damaged SE CRT - Hideous screech and no video
Posted by: raydeen on 2017-02-09 15:17:55
Ok, long story short: Bought an SE off of Ebay that had the blinking ? folder. I knew it meant bad drive or no drive. No problem. It had no internal drive, but the floppy worked. I made a system rescue disk, booted up, took a look at the specs (2MB RAM, etc.). Cool. I'll get a 50 pin SCSI drive. Got one, took the case off, and in the process of  pulling the power connector off the logic board, the back of my hand smacked the CRT. Didn't look like anything was damaged. I noticed the metal frame inside was really rusted out, due of course to the bad battery. I pulled it out and it had corroded things quite a bit but the logic board and every thing else seemed ok. Put everything back together, flipped on the power and got a nasty screech from the machine with no video. Did some troubleshooting (disconnected the speaker, new drive, etc.) but determined it was the CRT as that's pretty much where the sound appears to be coming from with the speaker disconnected. 

What do you guys think that I did, and from the above symptoms do you think it's something easily repairable/replaceable? Was it just coincidence and me routing around inside messed up a connection that  might have been just hanging on by a thread until I got my big fat hands in there?

I did look through some of the topics that I thought might have had an answer but didn't see anything that seemed to apply. If this has already been answered elsewhere, please direct me to the info.

Thanks in advance!
Posted by: Carboy7 on 2017-02-09 15:37:37
Smacked what part of the CRT? If you forcefully smacked the neck of the CRT, you may have damaged it...

I don't know any other instances where this has happened, so I'm at a :?: right now.
Posted by: unity on 2017-02-09 15:51:26
Sounds like you broke the neck/cathode. Examine again, carefully. Pay attention to the very end. Remove the board on the very end of the CRT, it pulls off and is keyed for putting back.
Posted by: raydeen on 2017-02-09 17:16:01
Well, here's some pictures. I honestly can't tell as I don't know exactly what I'm looking at and my vision isn't so good. 

2017-02-09 19.59.59.jpg

2017-02-09 20.00.45.jpg

2017-02-09 20.01.09.jpg

2017-02-09 20.02.00.jpg

2017-02-09 20.03.05.jpg

2017-02-09 20.03.19.jpg

2017-02-09 20.03.41.jpg

2017-02-09 20.04.04.jpg

2017-02-09 20.04.18.jpg

2017-02-09 20.06.01.jpg
Posted by: unity on 2017-02-09 17:31:17
Some pics are blurry, but sure looks like there are cracks all around the end there. Area around pins. Use a bright light and shine it around as you look.
Posted by: raydeen on 2017-02-09 18:45:30
I honestly can't tell if there are cracks or not. I can see that with the board put back on securely, when I power it up, there is some distinct electrical activity happening under the port on the board  (lot's of flicker as it's squealing). I'm guessing that a new CRT is the fix? If so, I may just go parts hunting to see if I can find an SE with a working tube, or I'll eventually gut it and stick my Raspberry Pi in there. I'd  rather not go that route yet as I've also ordered some blank floppies and a Syquest drive.

Live  and learn. Might just be a long term project. I probably need to just take everything apart anyway and see if I can clean all the rust or replace the internal chassis with one that isn't so nasty. I thought this was going to be an easy resurrection. 
Posted by: unity on 2017-02-09 19:30:59
It should be a subtle red glow, not what you described. So yes, I would say the CRT is shot.

Displays are easy to come by actually. There are a few on eBay. ALL compact Mac displays are interchangeable, excluding the Color Classic. So really your options are wide open to locate one.
Posted by: Compgeke on 2017-02-09 20:53:12
Yeah that describes a broken tube. I have one myself that does the same thing.
Posted by: Boctor on 2017-02-09 21:49:20
I may have a dying one, as well. There's a tiny, barely visible orange glow, but it's been like that for ages. Can picture tubes end up manufactured with an imperfect vacuum?
Posted by: techknight on 2017-02-11 12:48:33
Not usually, What happens is it develops leaks over time and becomes gassy. Or it can develop shorts. Gassy CRTs will give off a strong blue stream/glow around the electron gun when energized. 

But in the case above, it was physically broken. 
Posted by: BadGoldEagle on 2017-02-12 10:41:19
raydeen, where are you located? I'm in Europe and I have an extra CRT lying around. You can have it for the cost of shipping but if you're in the US, it will cost you an arm and a leg. Damn shipping rates!
Posted by: techknight on 2017-02-12 17:14:15
Just to ship a compact WITHIN the US has gotten ridiculous. To ship from NC to Maine was close to 60 bucks. 
Posted by: raydeen on 2017-02-13 15:32:38
raydeen, where are you located? I'm in Europe and I have an extra CRT lying around. You can have it for the cost of shipping but if you're in the US, it will cost you an arm and a leg. Damn shipping rates!
I appreciate the offer. I was able to find one on Ebay for $24 dollars or so plus another $12 for shipping or something like that. It hopefully arrives  unscathed on Wednesday. I'm going to take my time with this and have that be the last part that goes in. It's a good enough excuse  to take it apart and give it a thorough cleaning and get a new battery for the logic board. I want to get a steel brush and get most off the rust and corrosion off the frame. And if all else fails....well, it will have been a worthwhile learning experience. Thanks to all and If I do get it up and running, I'll post some pics. 🙂

Posted by: BadGoldEagle on 2017-02-14 01:48:36
Just to ship a compact WITHIN the US has gotten ridiculous. To ship from NC to Maine was close to 60 bucks. 
I paid $175 to have my Hyperdrive delivered to my front door. And that was actually cheap!!! FedEx wanted $350!
Posted by: raydeen on 2017-02-17 23:34:05
Ok all. More questions. I got the new CRT. Haven't unwrapped it yet as I'm working on getting the rust off the inside case. I've got everything completely apart and pretty much prepped to put back together. One thing I've found though is that the battery which had corroded had pretty much destroyed it's terminal. As I was looking over the board for any leaking capacitors or additional corrosion, I was checking out the speaker connector (seems fine) and the battery terminal, at which point I discovered that the contact nearest the speaker was pretty much gone. It just fell off - completely rusted/corroded, etc. Do I absolutely need to replace the battery and terminal or will things pretty much work without it?

Second question. The new tube didn't come with a yoke, so I'll have to transfer the old one over. Is there any safe way of taping the anode wire down somehow or insulating it so that I don't shock my butt into next week as I'm attempting to adjust the yoke? I'm planning on having my father-in-law help with some of this as he's got some experience with such things, but I'd rather not have either of us undergo any electrical shock therapy (although, it might help me out a bit). 

Also, anything I need to be cognizant of? I've watched (and re-watched) some YT vids on this stuff but knowledge is power. Thanks in advance for any tips and tricks.
Posted by: raydeen on 2017-03-12 05:42:19
Thought I'd update this thread with the outcome of it all:

Got the new CRT in, finally got the HD booted and initialized, added a Syquest drive (had to get a terminator), loaded 7.0.1, Clarisworks, After Dark 2.0, a couple of games (Might and Magic I still rocks!), Turbo Pascal and Think Pascal 4...having a blast.

I've named him Moby, because he was my white (well. kinda beige now) whale. Couldn't have done it without Tangi though. Got a new battery for her off of ebay - 5 to 6 hours on a charge.

http://www.ebay.com/itm/162200839956?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Getting a USB Ethernet to Wifi thing for her today, so we'll see how that works out. It should work as there's no drivers needed, just access to the unit's built  in browser to search for local wifi.

https://www.amazon.com/gp/product/B014SK2H6W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

In any case, thanks to all for all your help, support, and advice. 

2017-03-09 06.08.36.jpg

2017-03-12 08.04.40.jpg
Posted by: jimjimx on 2017-03-12 06:49:00
I may have a dying one, as well. There's a tiny, barely visible orange glow, but it's been like that for ages. Can picture tubes end up manufactured with an imperfect vacuum?
Cathode Ray Tubes, have a cathode heater (Filament), just like all other "Tubes / Valves"

That may be the orange glow your seeing.

The one time I broke the nipple, the ray gun was arcing blue....
Posted by: finkmac on 2017-03-12 07:41:54
Yup, I have a Classic with a broken tube that arcs like that whenever powered up.
Posted by: mraroid on 2017-03-13 08:01:39
Raydeen....

I don't understand how the USB Ethernet to Wifi thing would work.  Do you plug it into a ethernet port in your Mac?  How do you search for WiFi networks to connect to if it has no software?

I am looking for a easy solution for my Color Classic.  This might work??!!

Thanks

mraroid
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