Hello all! A friend of mine and I will be restoring her G4 Diamondtron monitor which at the moment does not power on despite being in excellent cosmetic condition. Going to document what we find here over time in case it comes in handy for others. At the moment it still needs to be fetched from her storage unit but very excited.
Restoration of G4 Diamondtron Monitor Bondi Blue
- Thread starter applesos
- Start date
croissantking
Well-known member
Good luck but I’ve heard the flyback goes quite a lot on these.
Franklinstein
Well-known member
The Diamondtrons are Mitsubishi's off-patent Trinitron clones. Usually they have faults in the HV circuit as mentioned, but whether it's a dodgy flyback, some other failed component, or just poor manufacturing (i.e., bad solder joints) it's hard to say. I have one of these and a later ADC CRT of the same style and they both have power faults. I haven't cared enough to try to fix them yet because I have the rarer (and much smaller footprint) LCD for the G3 and I usually upgrade video cards with non-ADC types anyway so don't have much use for an ADC CRT.
Oh yeah I don't think the 17" ones are known to be too reliable haha. We've both been looking for something to work on and this seems like it's within our respective skillsets but complex enough to keep things interesting. A CRT has comparably few traces to to test & since it doesn't power on we have fairly little to lose in trying to fix it. Not thrilled about discharging all those high voltage caps though.
mac27
Member
A few years ago someone did a very nice YouTube video of the flyback transformer replacement on one of these, here is the link.
If it doesn't power on (no signs of life at all? no amber/green power button LED?), that would almost make me think it's something other than the flyback but I am not certain.
If it doesn't power on (no signs of life at all? no amber/green power button LED?), that would almost make me think it's something other than the flyback but I am not certain.
I've yet to give it a look in person but the flyback is almost certainly not the only thing wrong with it if it is bad. It's been in storage and at some point in the interim stopped powering on during tests. Can't really say anything with confidence until we get it on the bench.
Brief update - cracked it open this afternoon and since there is 1) a very visible arc 2) no "click pop zoom" when the short resets the image, this may be a rare case where the flyback itself is performing acceptably and the point of failure is cracked solder and dust. Going to thoroughly clean the PCBs, reflow the connections to the flyback, and give things a look with the scope.
