6100 monitor rebuild

PrairieDillo

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OK, I have a 6100 out of a tempest that had original caps but seemed to work fine.

I think that I saw a replacement radial cap used down in the HV cage so it might have blown and been replaced at one time just to keep it working.

Well I've got a few questions.

I went the LV6100 route and changed that out first on the Main board. I did the caps as I had purchased the mega kit from bob sorta blindly and didn't need them all since the whole LV section isn't needed cause of hte LV6100.

Questions:

Frame mounted transistors, do you change these out if your monitor works fine?

The transistors that are on the deflection PCB screwed to heat sinks. Mine are working but should I change these also? It seems pointless to change transistors if they work. I'm not sure if the replacements from bob's kit are "upgrades"
http://therealbobroberts.net/k6100xlyot.html

In general changing EVERYTHING seems pointless so I'm trying to figure out what may fall out of range, need to be upgraded, or should be swapped for prev-maint.
 
If they work,I just clean them and re-apply heat sink compound.I haven't had any fail yet.That being said,I have found a few bad ones before.
 
I just figured that transistors don't actually fall out of range like a Cap.
 
For what it's worth, I got those transistors in Bob's kit and replaced my old ones. Those transistors run hot and I personally believe that 30 year old transistors are more likely to fail sooner than newer ones. And anything I can do to lessen the likelihood of damaging the tube is a good thing. Just my 2 cents.
 
I don't think it's necessary. While silicon can fail it really doesn't wear out or age like caps. It can help though with connection related problems
 
Yes, pull the bottlecap transistors and clean them of all thermal compound. That sh*t dries out and doesn't work worth a damn when dry. Get some replacement white silicone thermal compound (Fry's or electronics store) Make sure you don't use the stuff for CPUs (arctic silver etc. as some of these are electrically conductive). Use new micas if you have them otherwise place them on a flat surface and carefully wipe them clean. Apply a thin coating of thermal compound. PAPER thin is all you need. Not toothpaste thick. It is also a good idea to clean the monitor frame. I use a rag and WD40 and rub till the old stuff is gone.

Don't mess with the transistors on the deflection board heatsinks unless they are bad. The proper way to change them is to unsolder the transistors three legs and desolder the heatsink's 2 legs and remove as a unit.

I like the old bottlecap style transistors found on the monitors (2n3792 etc)as I think they were made with more durable (thicker) internal components able to withstand the heat better. If you wish, you can change them out with Bob's replacements as they will be clean already. Everything is rated for the load. I just think you might have a wider tolerance with the older ones. I could be wrong. Just my experience fixing about a hundred of these things. Don't throw away old transistors unless they test bad. You never know when you will need one.

Not sure what Bob is shipping for replacement transistors for the MPS transistors. These are getting to be unobtainium for the most part so hang onto those.
 
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I am about to do the same with a 6100 I will be selling shortly. It currently works fine and is really clean, but I'm putting in an LV2000 Lite, new caps and will clean and reapply white thermal compound where necessary. That's all that should be necessary. Maybe just keep the extra parts with the monitor as spares?
 
Yes, pull the bottlecap transistors and clean them of all thermal compound. That sh*t dries out and doesn't work worth a damn when dry. Get some replacement white silicone thermal compound (Fry's or electronics store) Make sure you don't use the stuff for CPUs (arctic silver etc. as some of these are electrically conductive). Use new micas if you have them otherwise place them on a flat surface and carefully wipe them clean. Apply a thin coating of thermal compound. PAPER thin is all you need. Not toothpaste thick. It is also a good idea to clean the monitor frame. I use a rag and WD40 and rub till the old stuff is gone.

Don't mess with the transistors on the deflection board heatsinks unless they are bad. The proper way to change them is to unsolder the transistors three legs and desolder the heatsink's 2 legs and remove as a unit.

I like the old bottlecap style transistors found on the monitors (2n3792 etc)as I think they were made with more durable (thicker) internal components able to withstand the heat better. If you wish, you can change them out with Bob's replacements as they will be clean already. Everything is rated for the load. I just think you might have a wider tolerance with the older ones. I could be wrong. Just my experience fixing about a hundred of these things. Don't throw away old transistors unless they test bad. You never know when you will need one.

Not sure what Bob is shipping for replacement transistors for the MPS transistors. These are getting to be unobtainium for the most part so hang onto those.

Awesome thanks... Bob threw in free white themal compound as well as new micas as his freebie to me so I have some new stuff there to put in. I'll just clean and re-dress the existing bottle cap transistors.
 
I've got two sets of working original bottlecap transistors for the 6100, would gladly trade them for the new transistors if you're interested.
 
Something I always struggle with is, what is better, original working ones, or new ones that are made in China...

I usually replace them but can't say for sure it's the best thing to do. At the least, replace the compound and even more important, make sure the the screws are tight.
 
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