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

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

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.

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,

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,

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.

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:smoke:

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,

Hi,

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