imac analog board caps

[mbates14]

Here is my other story of replacing caps.

I found an imac in the miami oxford campus dumpster, its a G3 500, with 128mb ram, blah blah blah.


So, I get it out, take it home, first thing I check are motherboard caps. non are physically damaged. So, i powered it up, it chirped, bonged, screen lit, started booting.

i bout hit the floor when it was working perfect. I'm like WTH??

so then the monitor went psyco. I knew they tossed it for something.

so i broke it all down, took me hours just to figure out how it came apart.

and well what do you know. Two blown nichicons right off the flyback secondaries. and countless countless bad solder. but right under those two caps, was a heatsink to the motherboard. Well, thier convection cooling methods suck balls.

the heat right into the analog board next to big caps. Nice one apple.

replaced the caps, resoldered all the transformers and coils. and resoldered the CRT socket, it was horrible. and resoldered the scan board/CRT board.

booted it again, and wow. I have a little more green. so it looks normal.

and what do ya know, it NEVER does it again. it works fine. Now im looking for a keyboard to try to crack the passwords to the osX logon. its panther or tiger, I can tell by th elogin and the boot screen. and I dont have the install CDs to tiger or panther. just jag.

[MD Willington]

We live in a throw away society, would you expect anything less...LOL

Plenty of computer parts in the dumpsters around campus here...May graduation.

[mbates14]

true. Sad, but true. Hey, beats me from paying 100 plus shipping on ebay for an iMac. one mans trash, is another mans treasure.

Another thing that makes me mad, they will throw 100% working fans, and televisions away. WTF.

[dmahalko]

replaced the caps, resoldered all the transformers and coils. and resoldered the CRT socket, it was horrible. and resoldered the scan board/CRT board.

Did you discharge the CRT before doing any of this? If not, maybe you were just lucky.

The picture tube itself acts like a giant capacitor, and it can store thousands of volts plus a fair bit of current for weeks after the monitor was last turned on or plugged in. (There are often safety circuits to discharge this power but there's no way to know if those are working, without checking with a high-voltage test probe.)


Before anyone else tries replacing caps in a monitor/TV, please take a look at this CRT Safety info before doing any work:

TV and Monitor CRT (Picture Tube) Information
sci.electronics.repair FAQ

[mbates14]

LOL. LOL. omg lol. Yes I discharged the CRT. Ive done electronic work for years, I just now stumbled across this forum. Weee, that would feel good. Not that I havent done it of course.


Actually, the flyback in these models have bleeder resistors. It will bleed off any voltage from the CRT after the unit is powered off for several minutes. I use a screwdriver and ground just to be sure.

Ill never forget the time several years ago when I forgot the monitor was live when I tried to remove the anode. OWWW.

[kc8adu]

a friend here works for the city and goes around the ud ghetto at moveout.
last year we got a 12x24 room full of stuff that way.
including p4 desktops,2 tb array still containing mp3's porn, movies,ect several 19" lcd's ect.
i guess the parents have deep pockets and will pay for new next year.

true. Sad, but true. Hey, beats me from paying 100 plus shipping on ebay for an iMac. one mans trash, is another mans treasure.

Another thing that makes me mad, they will throw 100% working fans, and televisions away. WTF.

[bushytails]

send me some of it. you can keep the porn though. :P

around here you're lucky to see a p2.... hell, a garage sale I stopped at a couple weeks ago wanted $450 for a barebones duron 750 system...

--Randy

[kc8adu]

change the ones on the psu while you are at it.
high failure rate.if you see fuzz on edges of images the psu caps are to blame.

we get them here often and nicknamed them icraps.
they are pretty but thats all.

Here is my other story of replacing caps.

I found an imac in the miami oxford campus dumpster, its a G3 500, with 128mb ram, blah blah blah.


So, I get it out, take it home, first thing I check are motherboard caps. non are physically damaged. So, i powered it up, it chirped, bonged, screen lit, started booting.

i bout hit the floor when it was working perfect. I'm like WTH??

so then the monitor went psyco. I knew they tossed it for something.

so i broke it all down, took me hours just to figure out how it came apart.

and well what do you know. Two blown nichicons right off the flyback secondaries. and countless countless bad solder. but right under those two caps, was a heatsink to the motherboard. Well, thier convection cooling methods suck balls.

the heat right into the analog board next to big caps. Nice one apple.

replaced the caps, resoldered all the transformers and coils. and resoldered the CRT socket, it was horrible. and resoldered the scan board/CRT board.

booted it again, and wow. I have a little more green. so it looks normal.

and what do ya know, it NEVER does it again. it works fine. Now im looking for a keyboard to try to crack the passwords to the osX logon. its panther or tiger, I can tell by th elogin and the boot screen. and I dont have the install CDs to tiger or panther. just jag.

[RJARRRPCGP]

Re: imac analog board caps

send me some of it. you can keep the porn though. :P

around here you're lucky to see a p2.... hell, a garage sale I stopped at a couple weeks ago wanted $450 for a barebones duron 750 system...

--Randy

I can build an Athlon 64 system for that much. LOL.