techknight
Well-known member
Welp, Another project on the table. Just picked up an Imagewriter II from Scott, And as expected, there are definitely a few things with these beasts that need attention.
1. You guessed it. Capacitors, Capacitors, Capacitors! A few of these just started to leak, while others appeared ok. But I decided to change every single one of them.
Getting this little bugger apart is definitely NOT easy. it takes quite a bit of thought, but eventually i did it.
First and foremost, Here is the driver board:
This basically is the Power Supply/Driver board. few things to note here, the two Sanyo-Panasonic proprietary STK-based power output ICs. Made for toshiba of course with thier own part number, but ive seen and changed enough of these to know exactly what they are. The one on the right is the voltage regulator output IC, and the one on the left is the stepper motor driver output IC.
This is the worrisome part, Even though these printers appaer to be fairly reliable, These power-pack ICs are definitely NOT known for reliability, So the first order of business is to recap this thing, and do some routine maintanance to keep these ICs cool and running under optimum conditions. Any slight variation, these ICs tend to fry themselves. If they do, well, its game over.
These ICs were used notoriously in integrated stereo amplifiers, and projection TV convergence applications, and some old tube-type RCA sets used them in the power supply, and they were known for failure. Ive changed a plenty.
So enough of that, You can probably see some spooge leaking from the left most tall capacitor, so they all gotta go!
Removed the cap, and shown the leakage.
Now here: I decided to remove the heatsink again, for routine service and mainanance of the STK power pack ICs. And the heatsink compound was dried and and crusty! Time to clean them up and re-grease the ICs. This will increase the service life drastically.
Here is the shot of the digital control board for the printer, and all of its capacitors that need replaced as well. Again, one of these caps had some spooge too!
and the solder joints on this board were really rickety. I touched most of them up already before I took this photo, but you can see clearly the ones I didnt and how bad they are.
This is undoubtedly the result of being in storage/outside/basement where constant moisture, and heating cooling cycles took place causing metal fatigue. Had to be fixed!
Oh and here is the undershot of the chassis:
More to come! as I dive into the thing mechanically. I may even retrobright the case too, because it is piss yellow, Even all the way through the plastic in the inside as well, which further proves my theory of environmental storage.
1. You guessed it. Capacitors, Capacitors, Capacitors! A few of these just started to leak, while others appeared ok. But I decided to change every single one of them.
Getting this little bugger apart is definitely NOT easy. it takes quite a bit of thought, but eventually i did it.
First and foremost, Here is the driver board:
This basically is the Power Supply/Driver board. few things to note here, the two Sanyo-Panasonic proprietary STK-based power output ICs. Made for toshiba of course with thier own part number, but ive seen and changed enough of these to know exactly what they are. The one on the right is the voltage regulator output IC, and the one on the left is the stepper motor driver output IC.
This is the worrisome part, Even though these printers appaer to be fairly reliable, These power-pack ICs are definitely NOT known for reliability, So the first order of business is to recap this thing, and do some routine maintanance to keep these ICs cool and running under optimum conditions. Any slight variation, these ICs tend to fry themselves. If they do, well, its game over.
These ICs were used notoriously in integrated stereo amplifiers, and projection TV convergence applications, and some old tube-type RCA sets used them in the power supply, and they were known for failure. Ive changed a plenty.
So enough of that, You can probably see some spooge leaking from the left most tall capacitor, so they all gotta go!
Removed the cap, and shown the leakage.
Now here: I decided to remove the heatsink again, for routine service and mainanance of the STK power pack ICs. And the heatsink compound was dried and and crusty! Time to clean them up and re-grease the ICs. This will increase the service life drastically.
Here is the shot of the digital control board for the printer, and all of its capacitors that need replaced as well. Again, one of these caps had some spooge too!
and the solder joints on this board were really rickety. I touched most of them up already before I took this photo, but you can see clearly the ones I didnt and how bad they are.
This is undoubtedly the result of being in storage/outside/basement where constant moisture, and heating cooling cycles took place causing metal fatigue. Had to be fixed!
Oh and here is the undershot of the chassis:
More to come! as I dive into the thing mechanically. I may even retrobright the case too, because it is piss yellow, Even all the way through the plastic in the inside as well, which further proves my theory of environmental storage.
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