Not a TV but

[mpatoray]

Solid state and with a CRT, I am working on an AT&T 55C terminal for a friend. A cap had popped in the Horizontal section taking out the HOT and some other components.

I have recapped this thing replacing all the crappy Elite brand caps with good 105 degree Panasonic. I found a replacement for the HOT, but not one of the fried diodes a GI8727, I cant seem to find a cross reference for it or specs online.

Does anyone out there have a cross book with this in it or a spec sheet so I can find a replacement?

Thanks,

Matt

[radiotvnut]

Where is the diode located in the circuit? Is it one of the diodes coming off the flyback?

[mpatoray]

Yep it is in that area, there was also a diode with the same part number near the HOT. It's one of those grey "squashed round" style silicon diodes.

[Findm-Keepm]

If it's a black epoxy diode, GI prefix is the maker, General Instruments. The 8727 sounds like a date code. Wyse made some AT&T monitors - what is the diode location, i.e. DXXX number. If it is anywhere near the FBT, use a fast rectifier. RGP20 series, MUR series or the like. If it is a glass diode, all bets are off, as it could be either a signal or Zener diode.

More info would be helpful. Generally, if you can give the semiconductor complement (listing) I can narrow it down by who made the thing. AT&T made very little of their computer stuff, so who the monitor was made by would also help.

Cheers,

[Findm-Keepm]

Originally Posted by mpatoray

Yep it is in that area, there was also a diode with the same part number near the HOT. It's one of those grey "squashed round" style silicon diodes.

Sounds like a BYV2X or BYV3X series diode - gray in color, not quite full spherical, with a black band on one end. Again, a DXXX designation would help.

If it is a scan derived supply (off the FBT), I generally use a BYV26D diode, as I have a stash of them. If it is a logic supply (5V), I'd use a RGP30 series didoe from a junk board -the RGP30's have a higher current rating than the BYV26D. The guidelines are 1) use a fast rectifier, and 2) use a high enough voltage/current rating to cover the draw.

Cheers,

[mpatoray]

Ok then part # RG3G
Location on board D403
No name on the boar, made in Taiwan, TCI-AJS 94V-0 looks to be an ID number on the board.

[zeno]

Originally Posted by mpatoray

Ok then part # RG3G
Location on board D403
No name on the boar, made in Taiwan, TCI-AJS 94V-0 looks to be an ID number on the board.

You can look up the FCC id # on the model tag at fcc.gov
to get the true make & model of the beast. Diode may also
be in pin ckt or an external damper. Trace out both ends &
let us know where they go will help. Monitors use some real
oddball stuff so be careful, even if you sub it there can be problems.
I would use the rubber fuse trick then be sure it isnt overheating.

73 Zeno

[Findm-Keepm]

Originally Posted by mpatoray

Ok then part # RG3G
Location on board D403
No name on the boar, made in Taiwan, TCI-AJS 94V-0 looks to be an ID number on the board.

Is RG3G printed on the diode? If so, an easy id. Your first post mentioned only GI8727.

Cheers,

[mpatoray]

Hi,

Both numbers are printed on the diode. Since the terminal is from 1987 I am sure the 8727 is the date code.