|
with a lot of papers I am suprised its still working. Must have been kept in a air cond enviroment its whole life (I think humidity is a big factor in paper cap deterioration). Anyway being that you are new to this my advice on only a cap or two at a time holds true. If you goof something up it is much easeier to fix if you only touched a couple parts vs many. You are replacing caps to add relialbility not to fix a problem. Of couse evertime you pull a chassis out there is risk of breaking something. this is where a test CRT would be handy. you setup the chassis on a stand to hold it secure with the underside exposed, and have a small CRT installed so you can check it after each change. the kinds of problems you risk are:
wrong value cap replaced (you replace a .001 with a .01)
wrong voltage rating cap replaced (a 600v replaced by a 400v)
bad connection made (new cap lead not properly secured and poor connection results).
wrong connection made (disconnected from point A reconnected to point B)
(easy to do, take lots of notes and only remove and replace one cap at a time)
polarity not correct (on polarized caps that is).
solder splash (too much solder applied drips off, spashes on parts under it).
Damage to parts around the cap. Esp important around delicate coils. Ham hands not allowed near the underside of a TV.
Damage to term strips/coil lugs/tube sockets, too much heat and phyical stress can ruin your day, esy true on coil lugs and tube sockets. On those if it looks tough I just cut off the old part and pig tail on the new. Not as neat looking but MUCH less stressful to the other part.
Heat damage to early diodes (not ofter used on old stuff but not impossilble, esp around the video detector) Germanium based solid state devices are damaged by heat, proper heat sinks must be used when soldering near them.
induced shorts, some chassis can be very dense with parts (any color zenith as an example) if you are not careful its easy to push a part like a disc cap and move it so the leads short out (been there done that). So care must be used in how you hold the chassis and what its set on top off (shop rag under chassis balled up pushes part when chassis is set down on it, causing short).
thats about all rookie errors I can think of off the top of my head.
be extra careful on reading the cap values they are often not spelled out the way the old cap is, exp old cap .01 new cap 103.
I use a cap tester to check whats coming out to whats going in just to avoid that one mistake.
|