Thread
Mac Classic 2 Problem Diagnosis.
Hey everyone!
I Bought a Macintosh Classic 2 off of Ebay for 10 $ (Plus 22 Shipping
) . It comes with a keyboard and a Mouse. The Description says that it starts up to a Flat line on the CRT and that the Vertical Sweep circuit is blown out. According to this site: http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html
They Say
"(1) The first thing to do is to check the P1 connector. If the problem is caused by connection/soldering failure of the P1 connector, you will see the burnt and/or charred P1 connector. Desolder, clean and resolder the P1 connector.
(2) If the problem still persists and the culprit is the U2 IC chip, replace it with a new TDA1170N chip.
When the U2 IC chip is broken, you may see another symptoms such as:
(1) The screen is shrunken to the upper/lower half of the monitor and the opposite half blacks out,
(2) The upper/lower half of the screen is extended in the vertical direction."
Does anyone know of this Problem on a Classic 2? The site above was made to repair the Macintosh SE and not any other...
Thanks!
I Bought a Macintosh Classic 2 off of Ebay for 10 $ (Plus 22 Shipping
) . It comes with a keyboard and a Mouse. The Description says that it starts up to a Flat line on the CRT and that the Vertical Sweep circuit is blown out. According to this site: http://www.biwa.ne.jp/~shamada/fullmac/repairEng.htmlThey Say
"(1) The first thing to do is to check the P1 connector. If the problem is caused by connection/soldering failure of the P1 connector, you will see the burnt and/or charred P1 connector. Desolder, clean and resolder the P1 connector.
(2) If the problem still persists and the culprit is the U2 IC chip, replace it with a new TDA1170N chip.
When the U2 IC chip is broken, you may see another symptoms such as:
(1) The screen is shrunken to the upper/lower half of the monitor and the opposite half blacks out,
(2) The upper/lower half of the screen is extended in the vertical direction."
Does anyone know of this Problem on a Classic 2? The site above was made to repair the Macintosh SE and not any other...
Thanks!
Lack of vertical deflection in a compact Mac is almost always caused by a poor connection. Resoldering (with fresh solder) the yoke connector should be performed as a matter of course. After doing so, pull out the cable and inspect the mating surfaces for oxidation, burning, etc. Repair/replace as necessary.
In very rare instances, the vertical deflection IC blows. IIRC, it is still a TDA1170 in the Classic II. This chip is very common, and probably still widely available. But resolder the yoke connector first, and see where things stand at that point.
In very rare instances, the vertical deflection IC blows. IIRC, it is still a TDA1170 in the Classic II. This chip is very common, and probably still widely available. But resolder the yoke connector first, and see where things stand at that point.
HI Mars478, I would tackle the vertical scan collapse first. As Tom said re-solder the connector and see it that works. The missing chime is most likely due to leaking capacitor on the logic board, the Classic II's are notorious for that. It's probably best to sort out one thing at a time. Just be careful not to run it too long with the white line showing, it will burn into the phosphorus, leaving you a permeant line.
Have you managed to download Tom's notes? http://68kmla.org/files/classicmac2.pdf The notes go into detail about the hazards of working inside a compact and how to discharge a CRT. The line is probably different because the CRT width is set wider.
Yeah I would. But you may not have to remove the analogue board to make the repairs.
According to Larry Pina's Mac Classic Repair book, most likely a horizontal white line is a symptom of a broken or cracked solder joint at connector BD1 on pin 1 on the bottom of the connector. The crack may also be on the width coil at LL2 or on the horizontal deflection capacitor at LL1.
In which case, all you need to do is remove the vinyl jacket and re-solder the joints at these locations.
Yeah, follow the advice you have been given here. Whacking the top of the case is not likely to hurt it, beyond what is already damaged, but it is a common remedy that might temporarily resolve this particular problem. What whacking it does is temporarily make contact with a weak or cracked solder joint, until the high frequencies running across it vibrates it apart again or the Mac gets jostled. Most likely in your case whacking the Mac caused a permanent break in the solder, too far apart to to be mitigated by this rough approach. If you allow it to sit power up for several hours, the expansion from the heat might allow a good whack to make a connection. Other other hand, it could further weaken other joints. The only way to fix this is to go in and re-solder the suspect joints.
This more or less confirms what most of us have been thinking.
Follow the good advice already given here, which is to resolder all joints that look suspect. Another thing to consider is replacing the capacitors on the analog board with new ones. By doing this, you will avoid the potential problem of leaking/bulging capacitors in the future. When working near the analog board, yoke, anode cap/lead and video board, make sure you have discharged the CRT to the ground lug first. This will ensure you are protected against serious injury. Possibly more importantly, take it very slow when working inside the machine -- knocking the end of the neck is easily done if you're not careful, and will result in a dead CRT.Hi, I left it running for about an hour and I got no video at all.Should I just resolder all the connections on the Analog board?
Arghhhhhh I WANT THIS TO WORK!!!
Chances are a cracked solder joint will not be visible to the naked eye. Take note of the locations I mentioned above per Larry Pina's repair instructions and re-solder all leads attached there, whether they appear to need it or not.
And yes your logicboard appears to show a leaky capacitor. It may need to be replaced, but definitely cleaned and probably re-soldered.
No you are going to identify the solder joints at the locations I and others specified above. If it is clear that the solder joint was scorched, and not just discolored, then you have a component failure as well. The best way to identify that is to look for scorch marks on the back of the white vinyl panel that covers the analogue board. Otherwise as pointed out earlier, cracks in solder joint are usually not visible without microscopic inspection. If you see any obvious defects, then by all means secure the connections. Otherwise, it is best to proceed location by location. If the places I have relayed from Larry Pina's book to not restore the Classic, I can give you a list of all the trouble spots to investigate. Though from the description of your problem, I gave you only those that applied.
In the time you've taken to post repeatedly, you could've soldered every joint on the analog board.
You've been given lots of good advice, why not take it? Solder -- don't just "reflow" -- the specific connections that have already been pointed out to you. The yoke connections are the first things to take care of. If you read the classicmac2.pdf doc, you will find advice that these connections should be resoldered whether or not you can see anything wrong, along with explanations for that advice.
The symptoms you describe are pretty common, and the likely solutions are well documented.
You've been given lots of good advice, why not take it? Solder -- don't just "reflow" -- the specific connections that have already been pointed out to you. The yoke connections are the first things to take care of. If you read the classicmac2.pdf doc, you will find advice that these connections should be resoldered whether or not you can see anything wrong, along with explanations for that advice.
The symptoms you describe are pretty common, and the likely solutions are well documented.
OK Thanks! I am just very nervous about screwing this up. I Played with soldering on an old PC Board and it was pretty easy so I am going to give it a go. This is my first (Hopefully) Useful Solder job ever.
Thanks to the support everyone has given, and sorry if I am pushy!
:beige: :b&w:
Thanks to the support everyone has given, and sorry if I am pushy!
:beige: :b&w:OK I soldered, I soldered the connections on the yoke. All the connections near the speaker.
Most of the CRT Controls as well. With new solder. I did some extra soldering on some suspicious joint, and I accidentally joined to solders together. I tried turning it on for a few seconds, it made a loud squeaking noise, and there was a bright light in the glass neck of the tube. I Quickly turned it off. I need to get a desoldering tool as well, but I do not know if this is progress or not.
Thanks!
Most of the CRT Controls as well. With new solder. I did some extra soldering on some suspicious joint, and I accidentally joined to solders together. I tried turning it on for a few seconds, it made a loud squeaking noise, and there was a bright light in the glass neck of the tube. I Quickly turned it off. I need to get a desoldering tool as well, but I do not know if this is progress or not.
Thanks!
OK So I de soldered the two joints I accidentally connected, and I resoldered half of the Vertical IC Chip.
It just displays no video, nothing at all. There is a faint orange light in the glass neck, and it makes a pop sound from the speaker at boot.
Would I have to replace the WHOLE analog board? or is it like the CRT or something.
Arghhhhh.
It just displays no video, nothing at all. There is a faint orange light in the glass neck, and it makes a pop sound from the speaker at boot.
Would I have to replace the WHOLE analog board? or is it like the CRT or something.
Arghhhhh.
Since nobody else has posted, I shall do so. By bridging two components together, and then applying power, you have most likely fried something on the analog board. Since I have limited hands-on experience with the insides of a compact Macintosh myself, do not take my word for it, but that is my initial thought. It might be a more sensible decision to simply acquire another compact instead of working further on your Classic II. Let this be a lesson to you in the future though - be less curious and take more time with repairs. It might be useful to let us know which joints you bridged.
Unfortunately wackymacs is right. You have killed something on that analog board, and possibly also damaged the crt (bright flashes emanating from within a crt are a very bad thing). Debugging that new problem (which is almost certainly more complex than the original one) on top of what you were already trying to do is asking a lot. You're better off getting another unit, and performing a transplant.
And if you need to solder anything in the future, please be sure to inspect your work very carefully before reapplying power. Haste is costly.
And if you need to solder anything in the future, please be sure to inspect your work very carefully before reapplying power. Haste is costly.
No, I bridged two joints on the same component...
There is not a bright flashing light in the back, its just a faint glow, like a lightbulb but VERY faint...
I'll take a picture. Would Washing the Mobo do anything? The MoBo does have some corrosion.
I really want this mac to work. Do you think a good idea is a replacement Analog board?
Arrrr.
There is not a bright flashing light in the back, its just a faint glow, like a lightbulb but VERY faint...
I'll take a picture. Would Washing the Mobo do anything? The MoBo does have some corrosion.
I really want this mac to work. Do you think a good idea is a replacement Analog board?
Arrrr.
Washing it probally will not help much of anything, you most likely fried something on the logic board, why you would power something while its obviously shorted out is beyond me.
Honestly seeing the progression of this thread I would not suggest you mess with another machine, there are things inside that could very well kill you. Along with your rushed, half hazard, total density, its just a recipe for danger
Find a machine on ebay that is in good working condition and be happy
Honestly seeing the progression of this thread I would not suggest you mess with another machine, there are things inside that could very well kill you. Along with your rushed, half hazard, total density, its just a recipe for danger
Find a machine on ebay that is in good working condition and be happy
noone was getting angry or slamming, if you look back on the thread what you might see is someone who really shouldnt be messing around with the insides of a mac, not following instructions, and when they did they did such a bad rush job they went and made things 10x worse
but I retract my statement, fry your mac, put your self in the hospital, do whatever you want because you have made it totally clear that is what your going to do anyway
And if you knew what you were doing you would not have killed your mac over a solder bridge
but I retract my statement, fry your mac, put your self in the hospital, do whatever you want because you have made it totally clear that is what your going to do anyway
And if you knew what you were doing you would not have killed your mac over a solder bridge
Thanks for your input spelling sheriff, don't you have somewhere else to troll
No. Both myself and tomlee told you that you've screwed something on the analog board. It's really that simple.
You clearly don't know what you are doing. Since attempting to repair this, you've made it ten times worse. If you knew what you were doing, you would NOT have "accidently" bridged two solder joints and THEN applied power.
Guys, a reminder from your friendly local mod, please remember to be nice to each other - I know we're all good at what we do, but remember we all had to start somewhere, and none of us are perfect - I remember when I first started playing with computers I made a few mistakes, as we all do.