I have a Toshiba D29C255 (Toshiba Trisync) with:
Tube: Toshiba A68LTF356X
Controller+Neck board: Toshiba PD1843/PD1844
Spent a while troubleshooting with a friend last night who is much more knowledgeable about CRTs than myself.
Issues currently pointing to the flyback, a Toshiba TFB5085AD.
I plan to recap everything it just to rule any in-obviously bad caps out and test all the relays, diodes, etc. on the board.
----- Assuming that it is the flyback, which considering age and pre-failure symptoms seems likely -----
Replacements appear to be unobtainable.
There is a guy in Spain who appears to be manufacturing new units, but this isn't in his catalog. However, the TFB5076AD is.
This leads me to the following:
I also discovered that apparently some D29CR55's come with the same flyback?
These appear to be similar in function, with the exception that they are 15/24KHz and don't auto-switch, and are missing some other bells and whistles present on the D29C255
https://5nhledx26hgbdeqkw5jga5vkjy-...sid=bf9eedacacaeb68433e19d625d6cf327#p1163944
A lot of D29CR55's also seem to come with a Toshiba TFB5076AD.
I'm fairly quickly learning more about how these things work, and by my understanding so far the yoke windings, and possibly neck board need to match what the flyback is manufactured for (aside from the obvious pinout and power compatibility)
So my question is currently is: Are the TFB5076AD and TFB5085AD specced identically and therefore interchangeable? Does anyone here know?
How would I go about finding out if so?
Datasheets on CRT flybacks seem to belong in a museum and everyone is afraid of snakes.
My current working hypothesis is that I would need to check resistance and inductance of the primary and secondary windings, and compare for an exact or near-exact match.
By my logic (which is sometimes wrong): If the flyback insulation has gone bad, it shouldn't affect these values too much as logic dictates that is only really a problem when you have HV going through it.
Additionally, if I can spec the TFB5085AD, I may be able to have a suitable aftermarket product made by someone with the necessary experience and equipment.
So, I'm reaching out here in hopes that someone with more experience with these specific configurations may be able to offer some knowledge, and that I may document it here.
Thank you very much for any help.
Tube: Toshiba A68LTF356X
Controller+Neck board: Toshiba PD1843/PD1844
Spent a while troubleshooting with a friend last night who is much more knowledgeable about CRTs than myself.
Issues currently pointing to the flyback, a Toshiba TFB5085AD.
I plan to recap everything it just to rule any in-obviously bad caps out and test all the relays, diodes, etc. on the board.
----- Assuming that it is the flyback, which considering age and pre-failure symptoms seems likely -----
Replacements appear to be unobtainable.
There is a guy in Spain who appears to be manufacturing new units, but this isn't in his catalog. However, the TFB5076AD is.
This leads me to the following:
I also discovered that apparently some D29CR55's come with the same flyback?
These appear to be similar in function, with the exception that they are 15/24KHz and don't auto-switch, and are missing some other bells and whistles present on the D29C255
https://5nhledx26hgbdeqkw5jga5vkjy-...sid=bf9eedacacaeb68433e19d625d6cf327#p1163944
A lot of D29CR55's also seem to come with a Toshiba TFB5076AD.
I'm fairly quickly learning more about how these things work, and by my understanding so far the yoke windings, and possibly neck board need to match what the flyback is manufactured for (aside from the obvious pinout and power compatibility)
So my question is currently is: Are the TFB5076AD and TFB5085AD specced identically and therefore interchangeable? Does anyone here know?
How would I go about finding out if so?
Datasheets on CRT flybacks seem to belong in a museum and everyone is afraid of snakes.
My current working hypothesis is that I would need to check resistance and inductance of the primary and secondary windings, and compare for an exact or near-exact match.
By my logic (which is sometimes wrong): If the flyback insulation has gone bad, it shouldn't affect these values too much as logic dictates that is only really a problem when you have HV going through it.
Additionally, if I can spec the TFB5085AD, I may be able to have a suitable aftermarket product made by someone with the necessary experience and equipment.
So, I'm reaching out here in hopes that someone with more experience with these specific configurations may be able to offer some knowledge, and that I may document it here.
Thank you very much for any help.
Last edited:
