iMac G3 DV Refurb

[displaced]

Hi all,

After my success with the SE, I thought I'd dig my nan's old iMac G3 DV out of the loft and see if I could get it working.

From what I remember, it works fine apart from one thing: the bottom third of the screen 'rolls up' under the rest of the display, and occasionally the whole display compresses vertically, with bright horizontal lines at the edges. When it was still in-use, a swift whack to the right-hand side would usually fix it for a while.

Given it was 'fixable' with a firm slap, I'm thinking there's likely a cracked solder joint somewhere in the analogue section. But while I'm there, would a recap be a good idea? The machine's 21 or so years old, but -- as with the logic board on the SE -- are the caps generally thought of as safe to leave untouched?

(as an aside, I've been watching this teardown on YouTube and... blimey, there's a lot of parts! Should be an... interesting?... one!)

 

[Elemenoh]

Do you have an ESR meter? That would help you test for caps that are actually out of spec instead of replacing all of them prophylactically.

 

[RetroViator]

After opening my iMac DV, I decided to proactively replace all the caps because I wasn’t sure the plastic would survive another attempt at opening the case. I would have replaced the flyback too, if replacements were available. I did replace the decaying speakers though.

 

[displaced]

Ah yes, excellent point — I’d read that the internal plastic frame is incredibly brittle.

I’ll start searching for a cap list (and a source for the speakers!)

Unfortunately I don’t have an ESR meter, but yeah, given the desire to open it up as few times as possible, I think I’ll just recap it!

 

[RetroViator]

Ah yes, excellent point — I’d read that the internal plastic frame is incredibly brittle.

I’ll start searching for a cap list (and a source for the speakers!)

Unfortunately I don’t have an ESR meter, but yeah, given the desire to open it up as few times as possible, I think I’ll just recap it!

I did test the caps in mine after removal, and they were still in spec, but on the low end of acceptable.

if you’re interested, you can read about my experience at https://retroviator.com/2021/05/29/apple-imac-dv/.

 

[Certificate of Excellence]

Hi all,

After my success with the SE, I thought I'd dig my nan's old iMac G3 DV out of the loft and see if I could get it working.

From what I remember, it works fine apart from one thing: the bottom third of the screen 'rolls up' under the rest of the display, and occasionally the whole display compresses vertically, with bright horizontal lines at the edges. When it was still in-use, a swift whack to the right-hand side would usually fix it for a while.

Given it was 'fixable' with a firm slap, I'm thinking there's likely a cracked solder joint somewhere in the analogue section. But while I'm there, would a recap be a good idea? The machine's 21 or so years old, but -- as with the logic board on the SE -- are the caps generally thought of as safe to leave untouched?

(as an aside, I've been watching this teardown on YouTube and... blimey, there's a lot of parts! Should be an... interesting?... one!)

I was told by my old neighbor (retired TV/electronics repair guy) that the cause of the 'slap fix" on crts usually is in fact dry solder joints at the CRT R/G/B electron gun joints and slapping it jostles those joints to provide a better connection returning normal function. Also slaps fixed loose tubes as well but thats older than what we're talking about here. I've not tried to do a CRT repair before myself (aside from discharging the crt when inside compact macs) but have a 21" trinitron that died last year (powers on but no picture) that I would love to get working again - unfortunately he passed away last year or I'd ask him for some help

 

[RetroViator]

I was told by my old neighbor (retired TV/electronics repair guy) that the cause of the 'slap fix" on crts usually is in fact dry solder joints at the CRT R/G/B electron gun joints and slapping it jostles those joints to provide a better connection returning normal function.

With compact Macs, the solder joints for the analog board's connectors are often cracked and need to be reflowed. It's a remarkably easy fix once you know what to look for. I suppose any joint subjected to high heat at significant voltage could be at risk.

 

[displaced]

Well, I’m halfway through the tear-down, and I’ve hit the ‘oh crap, the plastic CRT frame’s turned into a jigsaw puzzle!’ phase

I swear this stuff cracks if you look at it wrong. Easily the worst I’ve ever seen! I mean, it doesn’t just snap, it splinters across its surface.

Once I’ve discharged and removed the CRT, it’s gonna take a lot of patience and MEK solvent to get it back into one piece. Poor thing — it’ll never be quite so pretty again, but it’ll be working properly.

 

[RetroViator]

Well, I’m halfway through the tear-down, and I’ve hit the ‘oh crap, the plastic CRT frame’s turned into a jigsaw puzzle!’ phase

I swear this stuff cracks if you look at it wrong. Easily the worst I’ve ever seen! I mean, it doesn’t just snap, it splinters across its surface.

Once I’ve discharged and removed the CRT, it’s gonna take a lot of patience and MEK solvent to get it back into one piece. Poor thing — it’ll never be quite so pretty again, but it’ll be working properly.

Yep. Been there, done that.